tag:blogger.com,1999:blog-24810336222290070112024-03-04T22:05:20.787-08:00Railway Bob's Railway RestorationsUnknownnoreply@blogger.comBlogger31125tag:blogger.com,1999:blog-2481033622229007011.post-70341913527205906732014-04-22T20:18:00.001-07:002014-04-22T20:44:11.147-07:00What To Do When Canadian Tire No Longer Stocks The Part??<div style="text-align: center;">
<b><span style="font-size: large;">World Hancock 24-M-L-46 Air Motor Reverser Lever Missing</span></b></div>
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<b><span style="font-size: large;">Cab Restoration CPR 4-6-4 Royal Hudson #2858 </span></b></div>
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<u><b><span style="font-size: large;">At Canada Science & Technology Museum</span></b></u></div>
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<span style="font-size: large;">A project of Bytown Railway Society's "Dirty Hands Club"</span></div>
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<span style="font-size: large;">Bytown Railway Society's "Dirty Hands Club" has been restoring the cab of CPR 4-6-4 Royal Hudson #2858 at the Canada Science & Technology Museum in memory of long-time and founding member, Duncan Dufresne. The DHC has encountered many challenges in this project, not the least of which is missing parts, parts that have rusted or corroded, or parts that no longer function. </span><br />
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<span style="font-size: large;">When parts are no longer available from commercial sources, they have to be made from scratch. The parts can be made from standard metal bar stock using a metal lathe and a Bridgeport milling machine, or in the case of the Air motor reverser lever, cast in silicon bronze using the "lost-wax" method. </span><br />
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<span style="font-size: large;">This is but one small chapter in that restoration. </span><br />
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<b><span style="font-size: large;"><u>Step 1</u> - Find an original. Take Measurements. Take Photos. </span></b><br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpkPn6UAeyCQiEsJ5qsez6PG9zRqy6Hu9BO0Ei_WOYTFsEXTu0WqEvqhj18yVsOi5wobtPZ28LnIGEM0Yl-WMoP5bXEXZqwAAbJctzC24Gw6H0FYz_a0y-jlqpxWfaGrBv9pcCVbfDkWU/s1600/Img_5487-4.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpkPn6UAeyCQiEsJ5qsez6PG9zRqy6Hu9BO0Ei_WOYTFsEXTu0WqEvqhj18yVsOi5wobtPZ28LnIGEM0Yl-WMoP5bXEXZqwAAbJctzC24Gw6H0FYz_a0y-jlqpxWfaGrBv9pcCVbfDkWU/s1600/Img_5487-4.jpg" height="348" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: large;">Photos & Measurements From #2850 At Canadian Railway Museum "Exporail"</span></td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEixOhcNCrSE2OXwKy8JalMqSdYDHIq1oT0qWZjp9vH5G6UZ0jcS16PN3EWU5ozGnz3CjZ_WFbgw5-O4nifSeHQo4Ns6S_2t44-kVcmKArm36XaEiAiXTDUR4J23meAYrvv1okhg0w6Qu7Y/s1600/Img_5487-3.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEixOhcNCrSE2OXwKy8JalMqSdYDHIq1oT0qWZjp9vH5G6UZ0jcS16PN3EWU5ozGnz3CjZ_WFbgw5-O4nifSeHQo4Ns6S_2t44-kVcmKArm36XaEiAiXTDUR4J23meAYrvv1okhg0w6Qu7Y/s1600/Img_5487-3.jpg" height="318" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: large;">Photos of Air Motor Reverser Lever On CPR 4-6-4 #2850 at Canadian Railway Museum "Exporail"</span></td></tr>
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<span style="font-size: large;"><b><u>Step 2</u> - Make A Wooden Pattern</b></span><br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgh-WHMpSBTbE1DGGU2fQwVazaA_KYDdd7Z8aXydTi08snwdshl3okWQWrrRrZjrCBOvinTQ3cgPvme5J6uR896Y9v03DdO684606-nOj4o7Zm7lhgsIfi2eoTfI6seI6n4OlfZpaABGno/s1600/Dscn0094-2.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgh-WHMpSBTbE1DGGU2fQwVazaA_KYDdd7Z8aXydTi08snwdshl3okWQWrrRrZjrCBOvinTQ3cgPvme5J6uR896Y9v03DdO684606-nOj4o7Zm7lhgsIfi2eoTfI6seI6n4OlfZpaABGno/s1600/Dscn0094-2.jpg" height="228" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: large;">There are 16 pieces of wood in this pattern.</span> </td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjM45qxHkCxpMnfHYCvGFf7XwVzFSUR-_HL1GmAkZoMp5kvmZTi9MJv6nzR82lMyh1RU5J7G8W8CNerb0M3JhKi2gHM4mVM0A_8nOTu1r0PD4CIh-vKfErfV1ET2DOYgDvniE5v67-vnNk/s1600/Dscn0048.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjM45qxHkCxpMnfHYCvGFf7XwVzFSUR-_HL1GmAkZoMp5kvmZTi9MJv6nzR82lMyh1RU5J7G8W8CNerb0M3JhKi2gHM4mVM0A_8nOTu1r0PD4CIh-vKfErfV1ET2DOYgDvniE5v67-vnNk/s1600/Dscn0048.jpg" height="388" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: large;">Wooden Pattern of Air Motor Reverser Lever Before Painting</span></td></tr>
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<span style="font-size: large;"><b><u>Step 3</u> - Make RTV Rubber Molds From The Wooden Pattern</b></span><br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgByAqjez6VXcCKidzTer-pUWpE9bnOdbgJREW_0mjbirvgd0thvRI96n04stl4Q3oOWcwHmAd5Bj6UdCfxgJGQwLJyJAe-32xGy2KHzAIfczuqu08beeNXfnUBomlgHWvy0Du_Y025rV8/s1600/Dscn0115.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgByAqjez6VXcCKidzTer-pUWpE9bnOdbgJREW_0mjbirvgd0thvRI96n04stl4Q3oOWcwHmAd5Bj6UdCfxgJGQwLJyJAe-32xGy2KHzAIfczuqu08beeNXfnUBomlgHWvy0Du_Y025rV8/s1600/Dscn0115.jpg" height="472" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: large;">Making The Second Half of RTV Rubber Molds</span></td></tr>
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<span style="font-size: large;"><b><u>Step 4</u> - Make Wax Patterns From RTV Rubber Molds For "Lost Wax" Casting</b></span><br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjAX4j5a0fiQJH7ZFsNADGSlTILvHheVnumn5DynnWAuSnia5aV6F_xdAeIjC-MRwQA8bkz0WCUSzonKjTwxuYCxrdmjEKhq8YVzn7mDagdJ8pb6dkefUU_R1WYBWSDyprCftOmVFCiob0/s1600/Dscn0204-2.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjAX4j5a0fiQJH7ZFsNADGSlTILvHheVnumn5DynnWAuSnia5aV6F_xdAeIjC-MRwQA8bkz0WCUSzonKjTwxuYCxrdmjEKhq8YVzn7mDagdJ8pb6dkefUU_R1WYBWSDyprCftOmVFCiob0/s1600/Dscn0204-2.jpg" height="262" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: large;">Wax Patterns Being Made. Adding Sprues, Gates & Risers. The Completed "Lost Wax" Tree - Ready For Ceramic Slurry.</span></td></tr>
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<span style="font-size: large;"><b><u>Step 5</u> - Prepare Wax Patterns For Casting</b></span><br />
<span style="font-size: large;">Coat the "Lost Wax" tree in a slurry of ceramic shell and silica sand. Allow the slurry to air-dry. Repeat 8-10 times.</span><br />
<span style="font-size: large;">Fire the ceramic shell at 1700F for 30 minutes to melt out the wax and to create a ceramic mold. </span> <br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEibxOMBDRsX3CAS5k2YvszzHffG73K1daLv7bgbdunY4sB8X2GlOXqv6gUZfzkfaQPnanptvbpSqDg-zZUnZZ-16RfDbgnRlAeox9gwnhYaX0k5Wni8DaYtUVuyVEwDlKAjhIRgACFr0Fg/s1600/Dscn1632-2.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEibxOMBDRsX3CAS5k2YvszzHffG73K1daLv7bgbdunY4sB8X2GlOXqv6gUZfzkfaQPnanptvbpSqDg-zZUnZZ-16RfDbgnRlAeox9gwnhYaX0k5Wni8DaYtUVuyVEwDlKAjhIRgACFr0Fg/s1600/Dscn1632-2.jpg" height="356" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: large;">Ready For Baking. Wax Being Melted & Shell Being Fired. Ceramic Mold Ready For Pouring Bronze</span></td></tr>
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<span style="font-size: large;"><b><u>Step 6</u> - Melt & Pour Bronze</b></span><br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhmhP_ZfktTtKP7f3pSMgaGDOUifAKk5itbQm2X3TQ2MdIiKmWDHbSjEuOAUuTUSCyoixtWatOCv5haJnFufpjmDYu3b6D6jYmG06I0nJTxOPIpurT1I2uanWnPAFFR-NoKFE0AQ5FD07Y/s1600/Dscn1637-2.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhmhP_ZfktTtKP7f3pSMgaGDOUifAKk5itbQm2X3TQ2MdIiKmWDHbSjEuOAUuTUSCyoixtWatOCv5haJnFufpjmDYu3b6D6jYmG06I0nJTxOPIpurT1I2uanWnPAFFR-NoKFE0AQ5FD07Y/s1600/Dscn1637-2.jpg" height="330" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: large;">Melting The Bronze - 2200F. Pouring Molten Bronze Into Ceramic Molds</span></td></tr>
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<span style="font-size: large;">The wooden pattern was made by "Jedi Master" Ross Robinson and "Master
Caster" Bob Moore from measurements taken by John Bryant and Andy
Cameron at the Canadian Railway Museum, "Railexpo", at St Constant, QC. RTV rubber molds and wax patterns were made by Bob Moore. Bronze
castings, ceramic shells, and wax trees were made by Bronze Sculptor
Dale Dunning and Ryan. </span><br />
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<span style="font-size: large;"><b><u>Step 7</u> - Straight Out Of The Mold, Ready For Finishing</b></span><br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiDsO_iVwx-NwS6wlwjpfs1x75TK2oSHF3pHMfk2dJO6uXhNL7hgnqosbBRe67CP40WjLAlnIk7EmgB_KZsbcPDYDlnalc_auJZP0dypSVt657a2iHOX-q9c-BnnPuywvotGY-3Pw_hgDY/s1600/Dscn1656.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiDsO_iVwx-NwS6wlwjpfs1x75TK2oSHF3pHMfk2dJO6uXhNL7hgnqosbBRe67CP40WjLAlnIk7EmgB_KZsbcPDYDlnalc_auJZP0dypSVt657a2iHOX-q9c-BnnPuywvotGY-3Pw_hgDY/s1600/Dscn1656.jpg" height="412" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: large;">Ready For Finishing</span></td></tr>
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<span style="font-size: large;"><b><u>Step 8</u> - Machined, Fitted, & Installed</b></span><br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjEWk-hQXM7nPHRsDVR4jzCZ6HsveLwcRXDTrcyhOryk4EEEkd1SIkRxN_-OFqZXGrt4m_gXDFu4K7VfCqFWax3-A3ZkyqXVmtCFhLorhwu5Qw319WZU5z53BtKA4s6-h55N7BUlGPgP1c/s1600/Dscn1673-2.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjEWk-hQXM7nPHRsDVR4jzCZ6HsveLwcRXDTrcyhOryk4EEEkd1SIkRxN_-OFqZXGrt4m_gXDFu4K7VfCqFWax3-A3ZkyqXVmtCFhLorhwu5Qw319WZU5z53BtKA4s6-h55N7BUlGPgP1c/s1600/Dscn1673-2.jpg" height="412" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: large;">Machined, Fitted & Installed</span></td></tr>
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<span style="font-size: large;"><b>From Start To Finish</b></span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj78_U6NtPEUlr9ZuGDRjOulKSSAwVjrXE5j2IiowC-N0hS0wwm0rpc4bXZZa2ZcGJ4O7ReVn_ub9-6c8tC8Hqs4wMFcXW6BOGr6NvHQlXecqIilV74dz22HS5y7qc3ullDVvxPtQgQlQs/s1600/Dscn1662.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj78_U6NtPEUlr9ZuGDRjOulKSSAwVjrXE5j2IiowC-N0hS0wwm0rpc4bXZZa2ZcGJ4O7ReVn_ub9-6c8tC8Hqs4wMFcXW6BOGr6NvHQlXecqIilV74dz22HS5y7qc3ullDVvxPtQgQlQs/s1600/Dscn1662.jpg" height="590" width="640" /></a></div>
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<span style="font-size: large;">The "Dirty Hands Club" (a very, very informal crowd) gathers most
Wednesday and Saturday mornings at the Canada Science & Tech Museum to work
on the #2858 project and in the restoration of its fleet of operating
rolling stock. You can find them right in the back of the Museum
complex in Building #2495. Just follow the train tracks. <br /> </span><br />
<b><u><span style="font-size: large;">Some Other Bronze Castings With Their RTV Rubber Molds</span></u></b><br />
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<span style="font-size: large;"><br />Bob Moore</span>Unknownnoreply@blogger.com1tag:blogger.com,1999:blog-2481033622229007011.post-7121965405759961432014-04-22T15:48:00.002-07:002014-04-22T15:48:12.106-07:00Pyle Nuts - Part 3 - Pouring The BronzeSo far just a place-keeper. Unknownnoreply@blogger.com1tag:blogger.com,1999:blog-2481033622229007011.post-24409944480454322052013-07-20T16:45:00.002-07:002013-07-29T18:48:13.054-07:00Pyle Nuts - Part 2 - Wax Patterns & InvestmentsNow that we have <a href="http://railwaybobrestorations.blogspot.ca/2013/07/pyle-nuts-part-1-making-mold-box-rubber.html" target="_blank">our mold box and rubber mold made</a>, we are ready to produce wax patterns that replicate the Pyle nut. <br />
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<span style="font-size: large;"><b><u>Making The Wax Patterns</u></b></span><br />
A trip to the grocery store and we had some paraffin wax that we could melt. Wax should NEVER be melted by direct heat or flame! Very hazardous! A trip to the local Sally Ann and we picked up a rice-cooker. For our melting pot, a tin can rescued from the recycle bin did the job.<br />
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Poured about 1" water into the rice cooker, plugged it in. Placed a chunk of paraffin wax in the tin can, placed it in the water and let things heat up. After 15 minutes or so, we had molten paraffin wax. This is VERY hot so be careful!<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEigZGCL_obqXEpaVLl0-hSFE7YQnbSatG7ehdiKA-9lvmmp6LmHOkKfbn3V7GwAo7OvpErIIUcuqKvZlBsRuX6p6qrhvppP8Er0xixtslyGMZQX7Rl7Y55WUvDAdRHpukTxwtttFSesxjM/s1600/Dscn0083.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="532" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEigZGCL_obqXEpaVLl0-hSFE7YQnbSatG7ehdiKA-9lvmmp6LmHOkKfbn3V7GwAo7OvpErIIUcuqKvZlBsRuX6p6qrhvppP8Er0xixtslyGMZQX7Rl7Y55WUvDAdRHpukTxwtttFSesxjM/s640/Dscn0083.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Getting Ready For Pouring Wax</td></tr>
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While the wax was melting, we put some duct tape over one end of the rubber mold. A large rubber band kept the four pieces (the two mold-halves and the two mold boards) tightly together. Just in case we had some accidents, we placed the mold assembly into a large plastic lid (from one of the DHC's large cans of Folger's coffee).<br />
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Using some angled gas pliers, we lifted the tin of molten wax out of the rice cooker and slowly poured the wax into the top of the mold. <b>Make sure you are wearing safety glasses for this part! Molten wax can splash. </b><br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-iaprZLmHj92RtBtdMHY900dobXofU8XOTIaoWOhJBffDtHC1QBlRk87q1M1vd8ycSBdd1zio_1WS-QvUJfxkd7r055mdwjr0CrA0HKuh3v8Cr1S3gBxUFVXWqIqkGXwETTOV1kdRSHA/s1600/Dscn0082.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-iaprZLmHj92RtBtdMHY900dobXofU8XOTIaoWOhJBffDtHC1QBlRk87q1M1vd8ycSBdd1zio_1WS-QvUJfxkd7r055mdwjr0CrA0HKuh3v8Cr1S3gBxUFVXWqIqkGXwETTOV1kdRSHA/s640/Dscn0082.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Pouring Wax</td></tr>
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We let the molten wax cool for at least 30 minutes as the centre of the mold would still be liquid. As the wax cooled, the wax in the sprue started to shrink. This is normal as wax expands when liquid but shrinks when it turns solid.<br />
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We then removed the rubber band and slowly pried the two halves of the rubber mold apart. Voila! A perfect wax replica of our pattern. Now to make a whole bunch more. <br />
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<span style="font-size: large;"><b><u>Mounting The Wax Patterns</u></b></span><br />
Now that we have our wax patterns made, we next have to mount them on a central wax sprue. <br />
<br />
<br />Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2481033622229007011.post-30767793312076681282013-07-08T13:36:00.003-07:002013-07-20T17:30:03.993-07:00Pyle Nuts - Part 1 - Making The Mold Box & Rubber Mold<span style="font-size: large;"><b><u>Pyle Wing Nuts</u></b></span><br />
A Pyle wing nut has two vertical half-oval-shaped wings on each side of the nut. The centre of one wing is open. This allows the nut to be further tightened by inserting a small bar in the hole and tighetening the nut. The Pyle nut was used to close the lid on locomotive headlamps. <br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjAJqg-BENJr2BHLGZEDfIDggVx7A2Fydcr2QJDReI-zltqNpiedQT5c1m88g1GXpxZq_5L_KPz61zgXmGzKWS7sa9p-4QJcY-1n9PEzdU-XqEe4B4UXl9ltvYBSgEdSr7UJ1tnzCe4eok/s1600/Img_0000.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="590" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjAJqg-BENJr2BHLGZEDfIDggVx7A2Fydcr2QJDReI-zltqNpiedQT5c1m88g1GXpxZq_5L_KPz61zgXmGzKWS7sa9p-4QJcY-1n9PEzdU-XqEe4B4UXl9ltvYBSgEdSr7UJ1tnzCe4eok/s640/Img_0000.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Pattern For Pyle National Wing Nut</td></tr>
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Our objective is to cast 6 Pyle wing nuts in bronze. This will be done using the lost-wax or investment casting process. The Pyle nut has been made out of wood and painted black. Our next step is to make a mold box which will be used to make a rubber mold of the part.<br />
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Once we have the rubber mold made, we will then be able to make wax castings/patterns of the Pyle nut. <br />
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The wax castings are then placed in a cylinder with wax sprues, gates and risers added to the wax castings. We then pour casting plaster into the cylinder. Once the plaster has hardened, we'll bake out the wax leaving a hollow mold that's the exact shape of our Pyle nuts. Melt some bronze, pour it into the mold and we should have a Pyle wing nut.<br />
<br />
So let's get started with the first two steps - making a mold box and then the rubber mold. <br />
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<span style="font-size: large;"><b><u>1.0 Make The Mold Box</u></b></span><br />
1.1 Cut - 2 pcs 4" wide x 3" high x 3/4" thick Baltic birch. <br />
- 2 pcs 2 1/2" wide x 3" high x 3/4" thick Baltic birch.<br />
- 1 pc 6" wide x 6" long x 3/4" thick Baltic birch. <br />
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1.2 Drill holes in the two pieces 4"x 3" at ends for #8 x 1 1/2" Robertson screws. Holes are located 3/4" from top and bottom and 3/8" in from the edge.<br />
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1.3 Loosely fit, align, assemble, clamp four pieces together in the shape of a box.<br />
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1.4
With the 4"x 3" pieces aligned, insert a 1/8" drill into the screw
holes and drill holes into the edges of the two pieces of 2 1/2" x 3"
about 3/4" deep. This will prevent the plies on the 2 1/2"x 3" pieces
from splitting when the pieces are screwed together. Repeat this step
for all other screw holes. <br />
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1.5 Screw the four pieces together so as to ensure a good square and level fit.<br />
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1.6 For ease of assembly, stamp the tops of each piece with identifying letters/numbers <br />
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1.7 - Mark the outline of the box on the 6"x 6" base plate. Drill four 1/8" holes from the top in the middle of each side. <br />
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1.8 On the bottom side, countersink the holes drilled in 1.7.<br />
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1.9
Align the box with the top of the base. Insert a 1/8" drill into the screw
holes and drill holes into the bottom edge of the four box pieces about 3/4" deep. This will prevent the plies on the box pieces
from splitting when the box is screwed to the base plate. <br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjah_GltvsxjLlmJJOJrdr8flUmGYaEAZE7rvWDYrro_hCJA-C9qeZ1VbVeimJcMDB97qT0WNVpsZjbLcxhkiGAr4iZy04Guq1A5H_d7MD2zxQ_AzEjTeurLryCV0ijnWtAgROipUpDqeY/s1600/Img_0008.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="416" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjah_GltvsxjLlmJJOJrdr8flUmGYaEAZE7rvWDYrro_hCJA-C9qeZ1VbVeimJcMDB97qT0WNVpsZjbLcxhkiGAr4iZy04Guq1A5H_d7MD2zxQ_AzEjTeurLryCV0ijnWtAgROipUpDqeY/s640/Img_0008.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The Bits-&-Pieces Of The Mold Box, Cut, Marked & Ready To Assemble</td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjwxW21C0i49hW4c7r0ss1Gliq0iqS52eQXgRrS1f6h3rqwSJHTFneHkAWDTUvDaDuUo0v7x5n17nbrDplZ5nXXk1WZRl4nZVQnaqZFaBh-3p_0AAT3jNr1Xx01pVUYvxW309qF3jp3hwk/s1600/Img_0011.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="596" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjwxW21C0i49hW4c7r0ss1Gliq0iqS52eQXgRrS1f6h3rqwSJHTFneHkAWDTUvDaDuUo0v7x5n17nbrDplZ5nXXk1WZRl4nZVQnaqZFaBh-3p_0AAT3jNr1Xx01pVUYvxW309qF3jp3hwk/s640/Img_0011.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The Assembled Box & Base Plate Ready For Painting</td></tr>
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1.10 Disassemble the four side pieces. Paint the four side pieces and the 6"x 6" base plate with two coats of yellow paint. <br />
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1.11 Spray all pieces with two coats of clear lacquer. Dust talc powder onto all pieces after the lacquer has dried. <br />
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<span style="font-size: large;"><b><u>2.0 Making Bottom Half of Mold</u></b></span><br />
2.1 Coat the insides of the side pieces and the top of the base with Vaseline. This will form a mold-release so that the rubber will easily release from the pattern and mold box. Re-assemble the box to the base with the #8 x 1 1/2" Robertston screws.<br />
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2.2 Get some modelling clay from Craft Store (Wallacks, Michael's, etc). <br />
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2.3 Place 1 1/2" of modelling clay in the bottom of the mold box. Press the pattern into the centre of the clay up to the parting line. Push the modelling clay flush against the parting line of the pattern with an X-Acto knife. <br />
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2.4 Roll a 3/8" piece of modelling clay. Cut a section of the clay in half along the radius/ centre line. Press the half-round of modelling clay into the mold box between the ends of the pattern and the sides of the mold box and shape in place. This will form a sprue and riser for the wax to enter the mold. <br />
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2.5 It may be necessary to fill any gaps between the sides of the mold box so that the RTV rubber doesn't leak from the box. Using the X-Acto knife, press modelling clay into these gaps. <br />
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2.6 Clean excess clay off the pattern and from the sides of the mold box. . <br />
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2.7 Make "registration marks" in the four corners of the modelling clay. Press the blunt end of a Sharpie marker into the modelling clay so as to create round depressions. The "registration marks" will help align the two halves of the rubber mold together. <br />
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2.9 Apply Vaseline, oil, or grease to the sprue, riser, and registration marks.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHoT3TI0VahMO03IkEM1pDeOl-2JlIlyHPBTYa28wBtAtRkijihjRacE_C8q_iZYieM5G2Bp-yf-eQHWGyQhRz34E0Zo79esvI0jAPMtHjwMt_rgHMZyXyHMTqr6qcGmCvAEQfuwXmvkI/s1600/Dscn0044.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="622" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHoT3TI0VahMO03IkEM1pDeOl-2JlIlyHPBTYa28wBtAtRkijihjRacE_C8q_iZYieM5G2Bp-yf-eQHWGyQhRz34E0Zo79esvI0jAPMtHjwMt_rgHMZyXyHMTqr6qcGmCvAEQfuwXmvkI/s640/Dscn0044.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The Mold Box & Pattern Ready For Pouring Rubber</td></tr>
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<span style="font-size: large;"><b><u>3.0 Pour Liquid Rubber Into The Mold Box</u></b></span><br />
3.1 RTV rubber is a 2-part compound - the rubber which is in liquid format, and the catalyst which, when mixed with the rubber, will result in a solid rubber mass. There are two time elements to consider when using RTV rubber. The first is the "open time". This is the amount of time that the rubber can be worked with before it starts to harden. The second time element is "demold time". This is the amount of time required for the rubber to completely harden. The "open time" and "demold time" will depend upon the type and manufacturer. Refer to the manufacturer's instructions. <br />
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3.2 The "mix ratio" of rubber to catalyst will depend upon the type of rubber being used. Refer to the manufacturer's instructions. <br />
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3.3 We will be using <a href="http://www.alumilite.com/ProdDetail.cfm?Category=Silicone%20Rubber&Name=QuickSet" target="_blank">Alumilite Quick-Set Silicone Rubber</a>. The "open time" is 30 minutes. The "demold time" is 8-18 hours. The "mix ratio" of rubber to to catalyst is 10-to-1 (10:1). That is, for every 100 grams of rubber, we will need 10 grams of catalyst. <br />
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3.4 Gather the tools and materials required to mix rubber:<br />
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<td style="width: 215px;">__ RTV Rubber Kit</td>
<td style="width: 214px;">__ Weigh Scales</td>
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<td style="width: 215px;">__ Paper Coffee Cups (2)</td>
<td style="width: 214px;">__ Stir Sticks</td>
</tr>
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<td style="width: 215px;">__ Paper Towels</td>
<td style="width: 214px;">__ Mold Box</td>
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<td style="width: 215px;">__ Garbage Pail Close By</td>
<td style="width: 214px;">__ Rubber Gloves</td>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgIQdlZmac7W63wgbH2L3_UEq7kzDvWtFYEB-XgguOVUHY1Tp8y6doh-71cW5a_evUkdEF57pZaAw97ELuDy3o0faEOCJSMsASComJ-n63_30_zqrSohwMdkAp7L-E5yovezqAvDKTJEKM/s1600/Dscn0052.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgIQdlZmac7W63wgbH2L3_UEq7kzDvWtFYEB-XgguOVUHY1Tp8y6doh-71cW5a_evUkdEF57pZaAw97ELuDy3o0faEOCJSMsASComJ-n63_30_zqrSohwMdkAp7L-E5yovezqAvDKTJEKM/s640/Dscn0052.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Tools & Materials Required To Mix RTV Rubber</td></tr>
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3.5 Sand one of the rounded ends of the stir sticks so that one end is flat. This will allow the stir stick to get into the edges of the paper coffee cup when mixing the rubber and catalyst. Using a utility knife, cut the paper coffee cups back to a height of about 2 1/2"- 3". This will facilitate the measuring, stirring, and pouring of the liquid rubber.<br />
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3.5 We need to calculate the volume/weight of rubber required so as to
provide 1" of rubber over the highest part of the pattern. Pour water
into the mold box until it is 1" above the top of the pattern. Pour the
water into a paper coffee cup and weigh the water. For this project, the weight of the water is 100 grams and thus we will need 100 grams of liquid RTV rubber. <br />
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3.6 Place a dry coffee cup on the weigh scale. Using the weight scale, pour 100 grams of rubber into the cup. Then pour the catalyst on top of the rubber until the scale reads 110 grams. This will give us the 10:1 ratio of rubber to catalyst.<br />
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3.7 Thoroughly mix the rubber and accelerant together for 3-4 minutes. Slowly pour the mixed rubber into the top of the mold box in a thin string so as to minimize air bubbles. DO NOT pour the rubber onto the top of the pattern. <br />
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3.8 If you have access to a vacuum pump, remove the air bubbles from the RTV rubber.<br />
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3.9 Let rubber harden for 24 hours. <br />
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<span style="font-size: large;"><b><u>4.0 Add Resin/Plastic "Mold Boards"</u></b></span><br />
4.1 We will mix and pour a 1/4" layer of resin/ plastic on top of the rubber mold after cutting two registration marks into the hardened rubber. This will provide support and minimize deformation of the rubber mold when we join the two halves of the rubber mold together for pouring. <br />
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4.2 Plastic resins are a 2-part compound - the resin and the catalyst which are in liquid
format. The two, when mixed together, will result
in a solid plastic. There are two time elements to consider when
using resin. The first is the "open time". This is the amount of
time that the resin can be worked with before it starts to harden. The
second time element is "demold time". This is the amount of time
required for the resin to completely harden into a plastic. The "open time" and
"demold time" will depend upon the type and manufacturer. Refer to the
manufacturer's instructions.<br />
<br />
3.3 We will be using <a href="http://www.alumilite.com/ProdDetail.cfm?Category=Casting%20Resins&Name=Alumilite%20Regular" target="_blank">Alumilite Regular Castin Resin</a>. The "open
time" is 90 seconds. We will have to move quickly to mix the resin and catalyst, and to pour the mix into the mold box. The "demold time" is 8-18 hours. The "mix ratio"
of resin to catalyst is 1-to-1 (1:1). That is, for every 100 grams of resin, we will need 100 grams of catalyst.<br />
<br />
4.2 Using an X-Acto knife cut two V-shaped slots in the rubber mold next to the mold box. These will serve as registration marks for the plastic mold boards. <br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjSRo4F8pDCpT2rEYMAR-KttWh2mXKnbm2lsvAQ1PA_GPDutEk5ncueEKOLUXa7sE6WgbZJJIx8nPsqe1Qg99pULPr85nLzSopcoeLZ96QQSW0W5_PEaVO40TPW9ixf8_aQazpS_MP-l14/s1600/Dscn0060.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="628" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjSRo4F8pDCpT2rEYMAR-KttWh2mXKnbm2lsvAQ1PA_GPDutEk5ncueEKOLUXa7sE6WgbZJJIx8nPsqe1Qg99pULPr85nLzSopcoeLZ96QQSW0W5_PEaVO40TPW9ixf8_aQazpS_MP-l14/s640/Dscn0060.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Rubber Mold With Registration Marks Ready For Plastic "Mold Boards"</td></tr>
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4.4 We need to calculate the volume/weight of resin/plastic required so as to
provide 1/4"" of plastic over the top of the rubber. Pour water
into the mold box until it is 1/4" above the top of the rubber. Pour the
water into a paper coffee pot and weigh the water. For this project, the weight of the water is 50 grams. Since our mix ratio of Resin (Part A of our Alumilite) and Catalyst (Part B of our Alumilite) is 1:1 and we need a total of 50 grams of resin/catalyst mix, we will need 25 grams of resin and 25 grams of catalyst for this project. <br />
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4.7 Gather the materials and tools required to mix the resin::<br />
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<td style="width: 215px;">__ Plastic Resin Kit</td>
<td style="width: 214px;">__ Weigh Scales</td>
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<td style="width: 215px;">__ Paper Coffee Cups (3)</td>
<td style="width: 214px;">__ Stir Sticks</td>
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<td style="width: 215px;">__ Paper Towels</td>
<td style="width: 214px;">__ Mold Box</td>
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<td style="width: 215px;">__ Garbage Pail Close By</td>
<td style="width: 214px;">__ Rubber Gloves</td>
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4.8 Into one of the paper coffee cups, pour 25 grams of resin into one of the paper coffee cups. Call this cup "A". Into another paper coffee cup pour 25 grams of catalyst. Call this cup "B".<br />
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4.9 If you want, pour 3-4 drops of dye into cup "A" and stir until the mixture is a consistent colour. In our project we are going to use some brown dye. <br />
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4.10 Pour the contents of "A" into "B" and stir, making sure the stir stick reaches into the sides of the coffee cup. <br />
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4.11 Now pour the contents of "B" back into "A" and stir vigorously. This will make sure that we are mixing as much of the resin and catalyst together. <br />
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4.12 Pour the mixed contents of "A" slowly into the top of the mold box.<br />
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4.13 DO NOT try to pour any of the contents of "B" into the mold box. If dye has been added, the colour of "B" will be slightly different from the colour of "A" which will be very noticeable when the plastic sets in the mold box. It's around this time that the plastic starts to harden and, as you pour the contents of "B" into the mold box, air bubbles may start to appear. <br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZaeJqLc0LyL2iutcoLmc53O9Szkuu4Zx5AAJQsI6gU0fgDzkOGCiIeqo-jdj7xKY7bEVhN2VLj6k5VtysPV0djT-pJ2ovzHXsf1M3Mwb6iQTT80oJBcx_co6N1jBNl6GNULIuOtRS0Ps/s1600/Dscn0065.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="576" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZaeJqLc0LyL2iutcoLmc53O9Szkuu4Zx5AAJQsI6gU0fgDzkOGCiIeqo-jdj7xKY7bEVhN2VLj6k5VtysPV0djT-pJ2ovzHXsf1M3Mwb6iQTT80oJBcx_co6N1jBNl6GNULIuOtRS0Ps/s640/Dscn0065.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Plastic "Mold Boards" Just Poured</td></tr>
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4.14 Allow the resin to harden for 24 hours. <br />
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<span style="font-size: large;"><b><u>5.0 Demolding The Bottom Half Of the Rubber Mold</u></b></span><br />
5.1 Remove the 6"x 6" mold board from the bottom of the mold box. <br />
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5.2 Unscrew and remove the four mold box side pieces. <br />
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5.3 Remove the modelling clay from the pattern and the rubber. DO NOT disturb the pattern in the rubber!<br />
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5.4 If necessary, brush off/wash away any clay remaining on the pattern and the rubber. Regrease the sides of the mold box and base with Vaseline, oil, or grease. <br />
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5.5 With the plastic mold board flush to the bottom of the mold board, fasten the mold box sides around the rubber mold, pattern, and plastic with the #8 Roberston screws. Screw the mold box to the 6"x 6" base with #8 Robertson screws. <br />
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5.6 Using a full round of 3/8" diameter modelling clay from 2.4, lay the round modelling clay in the half-round channels created in 2.4 between the ends of the patterns and the sides of the mold box. This will form a round sprue and riser for the wax to enter the mold. <br />
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5.7 Liberally brush Vaseline/oil over the exposed pattern, modelling clay, AND rubber. <br />
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5.8 Calculate, mix, and pour liquid rubber into the mold box following the instructions in Sectin 3.0. Let stand for 24 hours. <br />
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5.9 Using an X-Acto knife cut two V-shaped slots in the rubber mold next to the mold box. These will serve as registration marks for the plastic mold boards.<br />
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5.10 Add 1/4" resin/plastic "mold board" on top of the solid rubber following the instruction in Section 4 AFTER cutting the two registration marks in 5.9. <br />
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5.11 Remove the mold box and base plate from around the rubber mold. <br />
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5.12 Separate the two halves of the rubber mold. Remove the pattern and modelling clay from the rubber mold. <br />
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5.13 Carefully trim excess rubber from the sides of the mold. <br />
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5.14 Reassemble the two halves of the rubber mold aligning the halves with the registration marks. Tape the two halves together. <br />
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5.15 The rubber mold is now ready for pouring molten wax into the mold.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjob8hboF7s4RWWVtzUE9qIdkJf3mKWs-4t5SVVFhMsd58BZgvK4JUSQnQoib5wbRrKwxWWTKeb1fyv0Dnqet_wJpVEGwGCWs9RcB9Soe_Rw442A6yb8ddzGrenTYHwtjt-oVIqI-4UNyk/s1600/Dscn0074.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="518" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjob8hboF7s4RWWVtzUE9qIdkJf3mKWs-4t5SVVFhMsd58BZgvK4JUSQnQoib5wbRrKwxWWTKeb1fyv0Dnqet_wJpVEGwGCWs9RcB9Soe_Rw442A6yb8ddzGrenTYHwtjt-oVIqI-4UNyk/s640/Dscn0074.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The Finished Rubber Mold Ready For "Waxing"</td></tr>
</tbody></table>
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Next up, we <a href="http://railwaybobrestorations.blogspot.ca/2013/07/pyle-nuts-part-2-wax-patterns.html" target="_blank">make some wax patterns and encase the patterns in some casting plaster</a>. Unknownnoreply@blogger.com1tag:blogger.com,1999:blog-2481033622229007011.post-80656425577260793712012-02-13T10:09:00.002-08:002012-03-30T08:00:49.531-07:00Marker Lantern Brackets - The Final ProductIn our previous post we chronicled one of the last days at Imbleau's Iron Foundry in Renfrew. Their last pour was on the following Tuesday, February 7th, 2012.<br />
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Our post prior to that were a set of instructions for making the green sand mold to pour the corner lantern brackets. Here's what the casting looked like about an hour after the molten iron had been poured into the mold at Imbleau's.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhghyg3FmBmIp3I_Nys4DZpe8w4CI1vXui-cFtRABdOXZG9281B1MH_BsfU6ON2WGkbx4wfhWRO15ppklbKX8R48f1pHnSAxbIDKob09iOC5x2PDNDjgbQ32V3hrWuAt-Lr2uNq8BT6FP4/s1600/IMG_3258.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhghyg3FmBmIp3I_Nys4DZpe8w4CI1vXui-cFtRABdOXZG9281B1MH_BsfU6ON2WGkbx4wfhWRO15ppklbKX8R48f1pHnSAxbIDKob09iOC5x2PDNDjgbQ32V3hrWuAt-Lr2uNq8BT6FP4/s640/IMG_3258.JPG" width="640" /></a></div>In case you're having difficulty seeing where the casting is, here's another photo with some added captions.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgqcrk-ps9z9juc27tr79NWMme5HfuvaebOl-D1Tg9znFKetMAZj1EWQOJTCFV3SJytlZgeErHH5aXadNu7IhSfPYcioC98SwNnYsqA5EAJj2ucUxtBdb3-MLHr21aANE3-HWaezqPtfPU/s1600/Img_3258A.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgqcrk-ps9z9juc27tr79NWMme5HfuvaebOl-D1Tg9znFKetMAZj1EWQOJTCFV3SJytlZgeErHH5aXadNu7IhSfPYcioC98SwNnYsqA5EAJj2ucUxtBdb3-MLHr21aANE3-HWaezqPtfPU/s640/Img_3258A.jpg" width="640" /></a></div>Here's a photo of another one of the brackets.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiPr5yny7jMsyYvHpLgNqg6DdEEe1sq_aR65xH26iFqx3FVefJyx-9oLTuCs1CjNNFfo35HPxesUXa6IkUI_tNQs4w_REPryj3RtdJCic1NLeGHPPXaGI_6gqmCEjkev-eIjsxd9ebn_jU/s1600/Img_3257A.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="358" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiPr5yny7jMsyYvHpLgNqg6DdEEe1sq_aR65xH26iFqx3FVefJyx-9oLTuCs1CjNNFfo35HPxesUXa6IkUI_tNQs4w_REPryj3RtdJCic1NLeGHPPXaGI_6gqmCEjkev-eIjsxd9ebn_jU/s640/Img_3257A.jpg" width="640" /></a></div>The steam is still rising from the green sand and the castings are still very, very hot. Don't touch!!<br />
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Just to recap on the process, we started off with an original casting that we had to duplicate. The hollows and holes were filled in by Jedi Master Ross producing the following pattern.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_dfi6r8pfc4TmGiWE5GK33SE7SrMbHiN3bRe64VFRiK5AtqjNox-uKSZcKcWq3gFwLLTmsM6-Fr4nW1U9tqux_i_h_L96L2QiDaxhLM22pIzgHAnnqkZMsqJi18c2wet2k4lVCjjgb5k/s1600/07+Front+View+w+Core+Prints.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_dfi6r8pfc4TmGiWE5GK33SE7SrMbHiN3bRe64VFRiK5AtqjNox-uKSZcKcWq3gFwLLTmsM6-Fr4nW1U9tqux_i_h_L96L2QiDaxhLM22pIzgHAnnqkZMsqJi18c2wet2k4lVCjjgb5k/s640/07+Front+View+w+Core+Prints.jpg" width="600" /></a></div>We next had to make a sand core to produce the holes and hollows that we had just filled up. So, Jedi Master Ross made a core box so that we could make sand cores. After a few modifications, we were able to start production of the sand cores.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjKW6Eueop8gBdCcEerwnKn4BCamuvo-jM4m99AcGOacCxqisPdsmQvdzyww2himU_IZtEcTS1AxArMtot-k21pfjcTl9sPxRknyvTyW_F-wbuhwndhRpyf6v8L5rP_wyXjuKp9HV3GGyo/s1600/12+Sand+Core+Back+View.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="630" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjKW6Eueop8gBdCcEerwnKn4BCamuvo-jM4m99AcGOacCxqisPdsmQvdzyww2himU_IZtEcTS1AxArMtot-k21pfjcTl9sPxRknyvTyW_F-wbuhwndhRpyf6v8L5rP_wyXjuKp9HV3GGyo/s640/12+Sand+Core+Back+View.jpg" width="640" /></a></div>Which, as you can visualize from the photo below, would nicely create the hollow that we need in the mold.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjEDLnOH9-S4-hE_jMiosyM3_EWikKS7O224iU79iKGdUXXx8ntZu_qaQZ2V_Cl9hieHYidpCat4Mto4296vLn2gMvpiXM0WIa8vC_QbkyLpLVAdQg_xbwblpu9FCf9HvtULKvJTXhiaaQ/s1600/09+Sand+Core+w+Pattern.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="494" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjEDLnOH9-S4-hE_jMiosyM3_EWikKS7O224iU79iKGdUXXx8ntZu_qaQZ2V_Cl9hieHYidpCat4Mto4296vLn2gMvpiXM0WIa8vC_QbkyLpLVAdQg_xbwblpu9FCf9HvtULKvJTXhiaaQ/s640/09+Sand+Core+w+Pattern.jpg" width="640" /></a></div>From there, we went on to make a dozen sand cores for our 12 castings - 6 for the flat lantern brackets and 6 for the corner lantern brackets.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiUibnMMbD-V2EtOWDXo5TnMw2qrzBXPQsI8bLBaq3WCyu8KaqF7PY-jyVUHh0xXyvgCY5JBgvUW5VGUuHrh8FqT4zGRCa1uAWk6ueuUqRHtO-D0VL0A91xk2kN86YIGdT4E9EVSxsHPCY/s1600/13+Dozen+Sand+Cores.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiUibnMMbD-V2EtOWDXo5TnMw2qrzBXPQsI8bLBaq3WCyu8KaqF7PY-jyVUHh0xXyvgCY5JBgvUW5VGUuHrh8FqT4zGRCa1uAWk6ueuUqRHtO-D0VL0A91xk2kN86YIGdT4E9EVSxsHPCY/s640/13+Dozen+Sand+Cores.jpg" width="600" /></a></div>One thing I learned with the first castings that I had done at Alumaloy was to test the sand cores and make sure that they fitted snugly into the green sand mold.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiVzwS73DKVED36HNW-gyr2CSGR6HymAGFqp2B-0fNRZbC1QPtW1Cb53xOilT3squzYtXafM9ec8EzCkTFofkJNq61SEVhDLurO78KkTm4l-NMjyWax9_r1eCmKYf3kWnfyq9ZMHT1T2Eg/s1600/Img_3162.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiVzwS73DKVED36HNW-gyr2CSGR6HymAGFqp2B-0fNRZbC1QPtW1Cb53xOilT3squzYtXafM9ec8EzCkTFofkJNq61SEVhDLurO78KkTm4l-NMjyWax9_r1eCmKYf3kWnfyq9ZMHT1T2Eg/s640/Img_3162.jpg" width="480" /></a></div>With the sand cores tested, we took our first batch up to Imbleau's for casting. Here's the pattern ready to go along with the 6 sand cores.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsf7zBBveGEDDDR1S38IfUpzdNdHv58-t1ZBA-6qmf_DhR_hVIzGOsZZXsMpEdwgSUw_dg56ovVcOESeR63Kz01OjAyhLBaiWMHoB4joXHg8BO3WokJbDu-ly_Op0cqAjXS_aqlDuAFLA/s1600/Img_3110.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsf7zBBveGEDDDR1S38IfUpzdNdHv58-t1ZBA-6qmf_DhR_hVIzGOsZZXsMpEdwgSUw_dg56ovVcOESeR63Kz01OjAyhLBaiWMHoB4joXHg8BO3WokJbDu-ly_Op0cqAjXS_aqlDuAFLA/s640/Img_3110.jpg" width="438" /></a></div>These were cast on Friday, January 27th. This is what the castings look like. The sprue, gate, and risers have been knocked off and you can still see the sand cores in the middle of the casting.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpFIseAiDbY5xC1r7kT1TQPV9C7er5j57EbLEMvzXgU3crybSpYMXpq2bhyphenhyphen4Xmon4J3BM4GdrNXTV6mvZieO-mWYmR0k-M46uhP3DtS6_DvehsxqXufO8QoNCKFy2mu39Nr38RdJsC9tY/s1600/Img_3261.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="580" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpFIseAiDbY5xC1r7kT1TQPV9C7er5j57EbLEMvzXgU3crybSpYMXpq2bhyphenhyphen4Xmon4J3BM4GdrNXTV6mvZieO-mWYmR0k-M46uhP3DtS6_DvehsxqXufO8QoNCKFy2mu39Nr38RdJsC9tY/s640/Img_3261.jpg" width="640" /></a></div>It was then that we discovered a challenge facing us. I had originally though that I could simply soak the casting in water and the sand core would disintegrate. So much for that idea! It took 15 minutes to sand-blast the sand core out of each casting. This is what the lot looks like with the sand cores removed and a bit more of the "flash" knocked off with a chipping hammer. Each one of those castings is a solid block of iron! <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjC7mm2x5-MbEUZ4b83ZG0NzttQ48aDN9xgeyQLBGxuufgvQmTbuv277nQ4B4Omie1Oor9TAvDNPJcDir3O_JkEniFLBvfhyphenhyphen7JUEeil3iNRKt_sWREiUxFH-RCPEPnp49EhuZ8zA6TR0H8/s1600/Img_3262.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="574" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjC7mm2x5-MbEUZ4b83ZG0NzttQ48aDN9xgeyQLBGxuufgvQmTbuv277nQ4B4Omie1Oor9TAvDNPJcDir3O_JkEniFLBvfhyphenhyphen7JUEeil3iNRKt_sWREiUxFH-RCPEPnp49EhuZ8zA6TR0H8/s640/Img_3262.jpg" width="640" /></a></div>I was completely surprised that we were able to get things along this far! I was expecting an unrecognizable blob of iron. <br />
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Of course, the fun had only just started. First step was to drill out the holes for the mounting screws. While most of the 24 holes (6 castings x 4 holes per casting = 24 holes), there were 4 holes that wouldn't centre. A bit of grinding with a Dremel solved that problem. <br />
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Next up was to grind off the flash and the rough spots. One thing I discovered was that the sand cores were a bit loose in the green sand mold with the result that we had an extra bit of iron in the flash. Next time, we'll have to make the sand cores so that there is a tighter fit. Oh well, that's one lesson learned, eh!?<br />
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And this is what the final product looks like before Master Painter Charls gave them three coats of paint.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj8sbKKcHczWTA_vpSEj4Shx7X2buqVjDeu_vifoit6Ak5cvzIYNKwe2jjYfqFWvK3tFwuOOACrILOs8gFgkuRQ939BXdJ6MdRU1vmJ8FCfg0Q8t8u_7qPtqWI7Q94RIWLKqHDwP86SES4/s1600/IMG_3278.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj8sbKKcHczWTA_vpSEj4Shx7X2buqVjDeu_vifoit6Ak5cvzIYNKwe2jjYfqFWvK3tFwuOOACrILOs8gFgkuRQ939BXdJ6MdRU1vmJ8FCfg0Q8t8u_7qPtqWI7Q94RIWLKqHDwP86SES4/s640/IMG_3278.JPG" width="640" /></a></div><br />
Not bad for a bunch of amateurs, eh!?Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2481033622229007011.post-90581868390526007902012-02-02T19:09:00.000-08:002012-02-02T19:09:48.099-08:00A Day At Imbleau's Foundry - The Last PourI took a trip up to Renfrew today to pick up the patterns and castings that I had dropped off last Thursday and to see the pouring for the patterns that I had dropped off on Friday. Today was going to be a sad day as this was the last day that Imbleau's, after 160 years, would be pouring iron. <br />
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When I arrived, molten iron was running continuously from the foundry into the large crucible. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-1cqAyKEIOOtlSjTr-s69svnfR-S_UBoMq_Vb_K5OklYjQjVg_erbb9074gOgls94-CioWSHQleqhcaNDulQmDSZS6z3BLKYRuVYZKUNmEB1PPWyj7hncjCNLXjTPOUSEkzBIAOV53Yc/s1600/IMG_3231.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-1cqAyKEIOOtlSjTr-s69svnfR-S_UBoMq_Vb_K5OklYjQjVg_erbb9074gOgls94-CioWSHQleqhcaNDulQmDSZS6z3BLKYRuVYZKUNmEB1PPWyj7hncjCNLXjTPOUSEkzBIAOV53Yc/s640/IMG_3231.JPG" width="640" /></a></div><br />
From there, each worker would place their smaller crucible on the ground. The foundryman would then tip the large crucible and red-hot molten iron would pour into their crucible. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjuKKBH8D_tr5Ze7GtCSv6BO0gg7k64IREQ4WI9M1x6ZWTAcmsCQRdGbcx7Wx_PWQpigILdmKbSCcwpRciOxEiFNIXfl5RU7_sgmr4C9ORa3exIArrMzyG0vA-5IFAkIbYkawYb4QCKFcw/s1600/IMG_3230.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjuKKBH8D_tr5Ze7GtCSv6BO0gg7k64IREQ4WI9M1x6ZWTAcmsCQRdGbcx7Wx_PWQpigILdmKbSCcwpRciOxEiFNIXfl5RU7_sgmr4C9ORa3exIArrMzyG0vA-5IFAkIbYkawYb4QCKFcw/s640/IMG_3230.JPG" width="640" /></a></div><br />
A large crucible suspended on a travelling crane was placed near this part of the operation and the workers would empty the molten iron into the larger crucible. Three workers would then manouver the large crucible into the rows of large sand molds and align the lip of the crucible until it was exactly into the right position to pour the molten iron in the sprue of the sand mold. The crucible was slowly tipped forward and molten iron poured into the mold. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjdbQ8O3WMhBOADCOW8prfe2bfQax-xDGBHAR8XELACuW5ctBufpom0l2LWezwCMtSkfuQ1Ax7SVzHLd12lJqhTCt-wBm_Vwds_Pcp9fU9fnSd6JFmLfh59UpDR5hCRF30S97uUa8bSxWQ/s1600/IMG_3235.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjdbQ8O3WMhBOADCOW8prfe2bfQax-xDGBHAR8XELACuW5ctBufpom0l2LWezwCMtSkfuQ1Ax7SVzHLd12lJqhTCt-wBm_Vwds_Pcp9fU9fnSd6JFmLfh59UpDR5hCRF30S97uUa8bSxWQ/s640/IMG_3235.JPG" width="640" /></a></div>While the pouring was going on from the large crucible, other workers would get their hand-held crucible charged with molten iron and then walk Popeye-like with the handle of the crucible resting on the top of their leg over to the smaller sand molds and pour the red-hot molten iron into the top of the sprue. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEji04kaSCHLdELep6BaQWP9KJ7tFtc11iuUwAXWhIXYKtdgnL1a2eaClaUzvUHxV3qa8FzTcbNccZBsNCpn6L5yHGQ4JliHWA2TYf3YwMrAoSTisbikKNVwIAo2QqoWgaeBjR4TgSYYcsA/s1600/Img_3240.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEji04kaSCHLdELep6BaQWP9KJ7tFtc11iuUwAXWhIXYKtdgnL1a2eaClaUzvUHxV3qa8FzTcbNccZBsNCpn6L5yHGQ4JliHWA2TYf3YwMrAoSTisbikKNVwIAo2QqoWgaeBjR4TgSYYcsA/s640/Img_3240.jpg" width="480" /></a></div>When the iron appeared at the top of the riser, the mold was full of red-hot molten iron. The heat from the iron immediately turned the moist sand mold into a bath of steam. Throughout the foundry, steam was rising up into the air clouding the busy workers with their crucibles full of molten iron. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiQx2km38d1Ps-MlpCYtikaE3cXwE-NouIisBQcEPo40ShpG8KPNWq4ksP8Wtu3Fsh5FO8pvPGkhD8OA2XmrU41YRh8YG-Pj3vRB8xjQ_rWkS8pEipm0uXV8DmsiLuETapTR2hVtaj9p8o/s1600/IMG_3243.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiQx2km38d1Ps-MlpCYtikaE3cXwE-NouIisBQcEPo40ShpG8KPNWq4ksP8Wtu3Fsh5FO8pvPGkhD8OA2XmrU41YRh8YG-Pj3vRB8xjQ_rWkS8pEipm0uXV8DmsiLuETapTR2hVtaj9p8o/s640/IMG_3243.JPG" width="640" /></a></div>Through the rising steam I could barely make out the workers with the large crucible pouring the large sand castings. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjvAzSQnvq4jpJm1kZwURhyeKq_hFZj9XqtjXWrjspbJ9FVUgzESE2hzuoR29_IrhrdHp1vqt_rwBMqp6ViGsc0xss5wC29rjfw_UedVkWZQFOd1VXbj3Z97Eoy1tA3tUvqGksGpJXNRxk/s1600/IMG_3246.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjvAzSQnvq4jpJm1kZwURhyeKq_hFZj9XqtjXWrjspbJ9FVUgzESE2hzuoR29_IrhrdHp1vqt_rwBMqp6ViGsc0xss5wC29rjfw_UedVkWZQFOd1VXbj3Z97Eoy1tA3tUvqGksGpJXNRxk/s640/IMG_3246.JPG" width="640" /></a></div>Each worker seemed to automatically know what to do. There were no orders being shouted out by the foremen. They all worked in unison. When the large crucible was moved over to the furnace, a semi-circle of workers would form. As their small crucible was filled, they would move to the other side of the circle and pour it into the large crucible, taking their place at the end of the line once again. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhQe8PHIEngbn71pxbhIwH2wrbFSaersHqqw33OIqvDhIZY3TEWFaW4vaKSRxFjf3U8A5ABO7t7d4xbPPvXRxtvg2DuKbnbnLDdZjzAWOSDdlspfGno39iquR3I4d0Y78dCLyDcEb6bHrY/s1600/IMG_3238.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhQe8PHIEngbn71pxbhIwH2wrbFSaersHqqw33OIqvDhIZY3TEWFaW4vaKSRxFjf3U8A5ABO7t7d4xbPPvXRxtvg2DuKbnbnLDdZjzAWOSDdlspfGno39iquR3I4d0Y78dCLyDcEb6bHrY/s640/IMG_3238.JPG" width="640" /></a></div>When the large crucible was filled, three workers would move it away from the furnace and the other workers would then get their smaller crucibles filled with molten iron. One worker would go off into the south-eastern corner of the building; another worker would go off into the north-western part, each one followed by another worker who prepared the sand molds for pouring - lift the weight off of the molds that had been poured, shove a flask over the mold, then place the weight on top of the mold. Right behind him was the worker with the molten iron. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg6Zgcs_2Z9SZvE0WGWdaRrnkdIUwWZ-AGkvApfeRIMFjhsAEIrFCzJX1z-UZBit8f9XLJq30UVc5iqRyYVHVmTkXVWXkdh51EVF2VPZDP-JIfxLYg0PTwXsInl-1fevMmUvZlsiq-sQw/s1600/IMG_3234.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg6Zgcs_2Z9SZvE0WGWdaRrnkdIUwWZ-AGkvApfeRIMFjhsAEIrFCzJX1z-UZBit8f9XLJq30UVc5iqRyYVHVmTkXVWXkdh51EVF2VPZDP-JIfxLYg0PTwXsInl-1fevMmUvZlsiq-sQw/s640/IMG_3234.JPG" width="640" /></a></div>As the pour was coming to an end, the workers not pouring molten iron would up-end the sand molds to expose the iron castings. This would allow them to cool off faster. The molds were up-ended into rows where the green sand would be reconditioned for the next molding session. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEijspgx_oNYxswihvHWNavEv3l2hQF3xwwJTQrVYty26GXq37BWan9FjwO2kFKphnjJ3JgmyR4kCvEpmtpKELhkCwsFbw5RNft_0DuiPM8YKX63mG83RgZR4XiJB0L2ynAVIKNJlcgTv5s/s1600/IMG_3250.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEijspgx_oNYxswihvHWNavEv3l2hQF3xwwJTQrVYty26GXq37BWan9FjwO2kFKphnjJ3JgmyR4kCvEpmtpKELhkCwsFbw5RNft_0DuiPM8YKX63mG83RgZR4XiJB0L2ynAVIKNJlcgTv5s/s640/IMG_3250.JPG" width="640" /></a></div>I peered into the steaming cauldron of black sand seeing if I could see my castings. Aha!! There at the end of the row was one of my corner brackets. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjB4e3cpXGCkV8pfXl4BAi6_bWdT8JwZWaXLczIezN1KqK8DR1yx6iFJs4It__LeWtRXaR8gUqIHNA69PkjXa6fdFnwhiHhfTA-6aRmftDSF1Q63xbO0ym1Rf2N48qnHK3RfJMzFvvcuxo/s1600/IMG_3257.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjB4e3cpXGCkV8pfXl4BAi6_bWdT8JwZWaXLczIezN1KqK8DR1yx6iFJs4It__LeWtRXaR8gUqIHNA69PkjXa6fdFnwhiHhfTA-6aRmftDSF1Q63xbO0ym1Rf2N48qnHK3RfJMzFvvcuxo/s640/IMG_3257.JPG" width="640" /></a></div>Finally, the last of the sand molds was filled with molten iron. It was now time to pull the plug on the foundry to empty it of the molten and unmelted iron that was mixed in with the red-hot and unburnt coke. The wire rope was pulled, the furnace doors opened at the bottom and a large roar of flame shot up to the ceiling as the whole contents of the furnace dropped to the ground. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJGmB_KEpDjtPXgCDfjhVWZQmG3qyJDNeRBdIbkwbIuC_0brZ1f9yy-6iwYh1_AOzYFDRYTiGC3Xbw39ygR6Z6Ra9jp8bE75aToQK3R5q8vZHbwYU3BXGReuLjIsozzQ5eJPt3hzWy4Ho/s1600/IMG_3255.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJGmB_KEpDjtPXgCDfjhVWZQmG3qyJDNeRBdIbkwbIuC_0brZ1f9yy-6iwYh1_AOzYFDRYTiGC3Xbw39ygR6Z6Ra9jp8bE75aToQK3R5q8vZHbwYU3BXGReuLjIsozzQ5eJPt3hzWy4Ho/s640/IMG_3255.JPG" width="640" /></a></div>Anyone standing in front of that inferno would have been cooked to a crisp. The flame settled down and one of the workers hosed a steady flow of water onto the fiery mass. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgEPj5dqMyPkYnijcKCzYzT3TLcVdmPxMed7l2Oya7nf5qa0cWHwsZJB8FaMfBBL0XZgNdwys2HCOkvpqT6KPGj-syFUB5oojtZ3tRdZbe_mrnFqAzGFomRpsTzp55HrbA0eujjZ31DSBc/s1600/IMG_3256.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgEPj5dqMyPkYnijcKCzYzT3TLcVdmPxMed7l2Oya7nf5qa0cWHwsZJB8FaMfBBL0XZgNdwys2HCOkvpqT6KPGj-syFUB5oojtZ3tRdZbe_mrnFqAzGFomRpsTzp55HrbA0eujjZ31DSBc/s640/IMG_3256.JPG" width="640" /></a></div>Hard to understand the significance of that fiery flame as the contents of the furnace dropped to the ground. It signalled the end of an era that had lasted for more than 160 years. Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2481033622229007011.post-56936913207669028302012-01-30T04:25:00.000-08:002012-01-30T04:25:19.052-08:00Marker Lantern Corner Brackets - Steps For Making Sand MoldsThe pattern for the Marker Lantern Corner Brackets consists of the following elements:<br />
<ol><li>Main Pattern (painted black with yellow core prints)</li>
<li>"False pattern" (painted blue)</li>
<li>"False core print" (unpainted)</li>
<li>Wing-nut bolt (painted blue)</li>
<li>Main sand core (irregular shape)</li>
<li>Wedge-shaped core print (Loose triangle-shaped piece of wood with the top chopped off)</li>
</ol><br />
The following are the suggested steps for creating the green sand mold:<br />
<br />
1) Place the blue false pattern face down on the drag. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhqirPtzqatOPgDLOIOybLW0oZ8Nq1HDUWbd3IyTE45H598XY5lTYCnc4KM50doazohPVsp-zhnJEnNijUcSeY-X6q1Patkm70NmTzz1bNN6nOqluTN5g0iUPTIT8K_66iuVpwAnlXw9QA/s1600/Img_3113.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhqirPtzqatOPgDLOIOybLW0oZ8Nq1HDUWbd3IyTE45H598XY5lTYCnc4KM50doazohPVsp-zhnJEnNijUcSeY-X6q1Patkm70NmTzz1bNN6nOqluTN5g0iUPTIT8K_66iuVpwAnlXw9QA/s640/Img_3113.jpg" width="480" /></a></div><br />
2) Place the black-and-yellow main pattern on top of the blue false pattern<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhyaotTM_YcRCTuZlr0Kr8dcgP4u9l7UmPa9GFErSHJ5nvnEnLiiyayoUrExYwQzQvQs-OsOjZzOvydC5qi6Soj8cofy2tugbnRdhGr7uuh-ZQtXOYT9gdNfaMSBKWzsZkIFaZ6ifDY3U4/s1600/Img_3114.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhyaotTM_YcRCTuZlr0Kr8dcgP4u9l7UmPa9GFErSHJ5nvnEnLiiyayoUrExYwQzQvQs-OsOjZzOvydC5qi6Soj8cofy2tugbnRdhGr7uuh-ZQtXOYT9gdNfaMSBKWzsZkIFaZ6ifDY3U4/s640/Img_3114.jpg" width="480" /></a></div><br />
3) Fill and ram, etc the drag with green sand. <br />
<br />
4) Turn the drag over to expose the top of the blue false pattern<br />
<br />
5) Using the two screws provided, remove the blue false pattern from the drag. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEho9cCO_A9mXhd2LuLZZDdufhyG8AiNWueIzaVLy9f1caUel6C5rZedbKYuHp7X4qABDjO71XscvIVaA4JPfPC-d_fjzrftDnZiTqDQuyZvD8ljE6qwnHwE3WjYZ_bWsu99A3eUWC4vjCE/s1600/Img_3126.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEho9cCO_A9mXhd2LuLZZDdufhyG8AiNWueIzaVLy9f1caUel6C5rZedbKYuHp7X4qABDjO71XscvIVaA4JPfPC-d_fjzrftDnZiTqDQuyZvD8ljE6qwnHwE3WjYZ_bWsu99A3eUWC4vjCE/s640/Img_3126.jpg" width="480" /></a></div><br />
6) Depending on the height of the alignment pins in the drag, the clearances between the cope and the drag may be very close. In order to allow for a better clearance, cut a triangular piece out of the drag as shown in the photo below. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhG1HSNycKEKZbMRyHIcEiaBLIJBzVkys555vcIFYCOQmlvrWArLoxQiLazTxpJ3_O4Pp59wmwp2SMZX5Mh2z6H81oazKSXDecrcrXKLiRzdVnWCkHgyk4o_T-gdJkJbsiT2-QtcrnPt7Y/s1600/Img_3128A.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhG1HSNycKEKZbMRyHIcEiaBLIJBzVkys555vcIFYCOQmlvrWArLoxQiLazTxpJ3_O4Pp59wmwp2SMZX5Mh2z6H81oazKSXDecrcrXKLiRzdVnWCkHgyk4o_T-gdJkJbsiT2-QtcrnPt7Y/s640/Img_3128A.jpg" width="640" /></a></div><div class="separator" style="clear: both; text-align: center;"></div><br />
7) Place the unpainted wedge-shaped core print into the drag on top of the exposed yellow core print<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgNLqKbgCoXFyBL_KxPkf7f-EVFGddZCQ5RKN-85-0fyE6sqWggc_-hsroSlAG0vdmtD4SNfR9cZlT9Inxy_SgA_gVh1mo5RROypyocHLC9Mjbkb5MHbXaeRKLgTJ3zJgSmZaiDDL0azK4/s1600/Img_3131.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgNLqKbgCoXFyBL_KxPkf7f-EVFGddZCQ5RKN-85-0fyE6sqWggc_-hsroSlAG0vdmtD4SNfR9cZlT9Inxy_SgA_gVh1mo5RROypyocHLC9Mjbkb5MHbXaeRKLgTJ3zJgSmZaiDDL0azK4/s640/Img_3131.jpg" width="480" /></a></div><br />
8) Place the cope on the drag. Fill and ram, etc the cope with green sand. <br />
9) Lift cope off of the drag. Cut in sprues, gates, risers, etc.<br />
<br />
10) Rap and lift out the unpainted wedge-shaped core print. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiM8N-PxO4qkaDW3lwoIaKb7T-gCNVgN8OMNR5xesxV-knliNAhwp-Rr-VKMbdRihqiaeJY-ti9aBN3_lcn87GKzff-e-nk22IeF_wot5lXEB-RGCQVNOOe8vjEZb3bUJSTdXaFfZIhBR0/s1600/Img_3143.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiM8N-PxO4qkaDW3lwoIaKb7T-gCNVgN8OMNR5xesxV-knliNAhwp-Rr-VKMbdRihqiaeJY-ti9aBN3_lcn87GKzff-e-nk22IeF_wot5lXEB-RGCQVNOOe8vjEZb3bUJSTdXaFfZIhBR0/s640/Img_3143.jpg" width="480" /></a></div><br />
11) Insert the blue wing-nut bolt into the threaded hole in the bottom of the yellow-and-black main pattern. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgT32THj5BiSKLnbxAFRb7klBg0yfnZdxDCdJHVaKBA-UfnMIqbgc-NyuE84NEWgPobMUTsambho8Ngenpw4D4E9MAzk4CyDfc05Fqd8jZQJjCfgJaQkg1Su4N99qRAy1ZD8Q6WLiodhG0/s1600/Img_3152.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgT32THj5BiSKLnbxAFRb7klBg0yfnZdxDCdJHVaKBA-UfnMIqbgc-NyuE84NEWgPobMUTsambho8Ngenpw4D4E9MAzk4CyDfc05Fqd8jZQJjCfgJaQkg1Su4N99qRAy1ZD8Q6WLiodhG0/s640/Img_3152.jpg" width="480" /></a></div><br />
12) Rap and remove the yellow-and-black main pattern. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjRfLOCBybPlXHJll0XOD3BGu0OsZJzHjMy3e2ryDj7u4yaUU2NG7w1E13fEQK7i9H6NlibPm0bJ-ZC4mtzPCjWwsYc3nSSTtKEtR4xH-neRohTYqoY3TiXLQdm-6esNp23yHPZmaQDzrU/s1600/Img_3157.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjRfLOCBybPlXHJll0XOD3BGu0OsZJzHjMy3e2ryDj7u4yaUU2NG7w1E13fEQK7i9H6NlibPm0bJ-ZC4mtzPCjWwsYc3nSSTtKEtR4xH-neRohTYqoY3TiXLQdm-6esNp23yHPZmaQDzrU/s640/Img_3157.jpg" width="512" /></a></div><br />
13) Finish off the rest of the mold, etc. <br />
<br />
14) Insert the main sand core<br />
<br />
15) Insert the wedge-shaped sand core<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJu5WBprTnaRkId1rFkpK8SWXaes47qXV8GHtqthhiPqb0fs7pJsUMvWaYqpynW9e6TE-XuJqySsQ0Xm5b8OXEKSkCiHorGtdlwLEcPjpgLAxwLtknCmGsHWe1Chu-pKjA3dupUgUPVck/s1600/Img_3162.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJu5WBprTnaRkId1rFkpK8SWXaes47qXV8GHtqthhiPqb0fs7pJsUMvWaYqpynW9e6TE-XuJqySsQ0Xm5b8OXEKSkCiHorGtdlwLEcPjpgLAxwLtknCmGsHWe1Chu-pKjA3dupUgUPVck/s640/Img_3162.jpg" width="480" /></a></div><br />
16 Finish off the rest of the mold, etcUnknownnoreply@blogger.com0tag:blogger.com,1999:blog-2481033622229007011.post-29974308224797647252012-01-21T15:30:00.000-08:002012-01-21T15:30:59.386-08:00Marker Lantern Brackets - We Finish The Sand CoresWell, after multitudinous fine tunings after casting each sand core, we finally got the last 4 to slip out of the core box "relatively" easy. There's still one minor major undercut which we've been trying to fix with some epoxy glue. We had a splinter shave off of the box that fills in the bottom core print. After 3 tries at fillng the shaving, we approached reasonable success. One last attempt. Only problem is we've got a dozen sand cores all cast which is exactly what we need. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhagkSSzJX4ylnGZWRYNY1FMpW6EJhXDx0XvHs7RYNI1r-RGUxo8b_Y3ESV5JpjMZOz2UfzEygKKjKpg2DiWTAhC15cR_httOeWUtTenXZuYJq9FbI8p967eT6o1XdD3aIfO4-61ateCOI/s1600/13+Dozen+Sand+Cores.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhagkSSzJX4ylnGZWRYNY1FMpW6EJhXDx0XvHs7RYNI1r-RGUxo8b_Y3ESV5JpjMZOz2UfzEygKKjKpg2DiWTAhC15cR_httOeWUtTenXZuYJq9FbI8p967eT6o1XdD3aIfO4-61ateCOI/s640/13+Dozen+Sand+Cores.jpg" width="600" /></a></div><br />
However, if we decide to go into full-scale production, we'll fine tune them even more. Next up, we're going to test the sand cores in the green sand to make sure that they slide easily into the mold and rest where they should rest. But that's another story. Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2481033622229007011.post-79512710258325982932012-01-08T17:15:00.000-08:002012-01-21T15:25:11.074-08:00Marker Lantern Brackets - Now Here's A Challenge!With a lot of old castings no longer available from the catalogue (they got deleted decades ago!), it gets a bit difficult to find them when you need them. The only alternative is to make some patterns and get them cast at a foundry. That's the problem we're facing with some brackets to hold marker lanterns that go on the end of a train - either on each side at the back end of the caboose or on the back end of the business car. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3qXORZEqcb52Rm-tm5O_2SMwSK6zKOrQdja5U3nG3LO2j0q7E6azL5hb_TCFHo-dyXo7jC_qKed9RmylEFFJcU-dTiOv2QxewRpszReKSU8-BEMatYE5T-TSPpJt1u-2Y_mnjTQDX1tw/s1600/00+Corner+Bracket+w+Lantern.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="467" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3qXORZEqcb52Rm-tm5O_2SMwSK6zKOrQdja5U3nG3LO2j0q7E6azL5hb_TCFHo-dyXo7jC_qKed9RmylEFFJcU-dTiOv2QxewRpszReKSU8-BEMatYE5T-TSPpJt1u-2Y_mnjTQDX1tw/s640/00+Corner+Bracket+w+Lantern.jpg" width="640" /></a></div>However, all is not lost! If you happen to have at least one casting, you can always use that casting to make a pattern. Such was the case at Bytown. We just happened to have two corner brackets and one "flat" bracket. Here's a close-up of one of the corner brackets. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEdROzWBKARMmY_BTl4gydoRwsm5KCoibf9HYaJUI4t_Iia52kSQ8t_3CKHhWcEeBxwG-VeERReagy0szVKSJMmaRil3H9G41Twzu03pq_-9BjWWBFXV28L0Vl1__vlj5X81UadRSUIlM/s1600/01+Front+View.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="636" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEdROzWBKARMmY_BTl4gydoRwsm5KCoibf9HYaJUI4t_Iia52kSQ8t_3CKHhWcEeBxwG-VeERReagy0szVKSJMmaRil3H9G41Twzu03pq_-9BjWWBFXV28L0Vl1__vlj5X81UadRSUIlM/s640/01+Front+View.jpg" width="640" /></a></div><br />
It's kind of obvious that you just can't put it face-down in the flask, ram in some green sand, and extract the corner bracket so that we have a nice clean mold that we can then fill up with molten metal. No-sireee! Life is never that simple.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj45jAPOnnzr3DFAZzOIv3zGDzqM9iCE8CxM_PseJfpSlucLQQJipLr92nqYVqjYikyhVnPbNCQLfyDWh-WrdOKTtichdy5QhL967ZArib1Oev5hjSBb_TlMnl0CTUTusRpY4yFppyJ6eA/s1600/02+Top+Front+View.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj45jAPOnnzr3DFAZzOIv3zGDzqM9iCE8CxM_PseJfpSlucLQQJipLr92nqYVqjYikyhVnPbNCQLfyDWh-WrdOKTtichdy5QhL967ZArib1Oev5hjSBb_TlMnl0CTUTusRpY4yFppyJ6eA/s640/02+Top+Front+View.jpg" width="616" /></a></div><br />
And when you look at this casting from the top, it becomes very obvious that this could get a little complicated, particularly when it comes time to making the sand core for this casting. We have a hole right through the middle of the casting and a slot that only goes partly down the front. The lantern simply slides into the slot and is held in place by the partial slot. <br />
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Fortunately, Jedi Master Ross, with his years of experience in using an existing casting for a pattern, knew what to do and quickly glued pieces of wood to the casting to make "core prints". Here's what he came up with for the flat casting (the corner casting is a bit more complex but we'll get into that one a little later).<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1b3UPziHH_l3-xdm7i7I4bbjbPRtk35IJ7Et37qTmD3B7ujUKTNPGwv7Y5ywl_KXvMa5Fl_rqXkGTlyZ10vF9WfYM2jgZYALP4fMgkzhrSPLhteZ54ZJcEWAjd79k1mtm8dW6FbRCy48/s1600/07+Front+View+w+Core+Prints.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1b3UPziHH_l3-xdm7i7I4bbjbPRtk35IJ7Et37qTmD3B7ujUKTNPGwv7Y5ywl_KXvMa5Fl_rqXkGTlyZ10vF9WfYM2jgZYALP4fMgkzhrSPLhteZ54ZJcEWAjd79k1mtm8dW6FbRCy48/s640/07+Front+View+w+Core+Prints.jpg" width="600" /></a></div>If you compare this photo with the ones at the top of the post, you'll quickly see what he did. He glued a piece of wood into the slot, then a piece of wood on the top, and a piece of wood on the bottom. The piece of wood in the slot fills up the slot (obviously!). The top and bottom piece form the "core print" which will hold a sand core in place. It's the sand core that will replicate the "hollow" in the casting when the molten metal is poured into the green-sand mold.<br />
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So far, so good. But that's the easy part. We now come to the very, very difficult part - making the core box which we can use to make a sand core. If you take a peek back into the castings at the top, you will see that there are all kinds of lines and shapes going in all directions. First we have a slot that goes from the top of the casting to the bottom of the casting. Then we have a hollow cone that goes from the top all the way to the bottom of the casting. As the cone goes down from the top to the bottom the sides get narrower and narrower. Combine the full-length slot and the cone with the partial slot in the front and you get a very complex core box!<br />
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However, that problem had been solved by the Jedi Master at the same time that he modified the casting with the 3 pieces of wood. He had made the core box. There was only one problem. Actually, there were several but only one related to this casting. Because of the different lines going in all directions, the as-built sand core (which was a 2-piece "split mold") wouldn't release from the core box. The only way to get the sand core out of the core box was to break it all apart - which would defeat the original purpose of the sand core - n'est-ce pas!?<br />
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And so Ross handed the problem over to me to solve. It took 3 days of focused effort and 8 attempts at modifications, trial and error to start to solve the problem. Here's what the more recent disasters looked like before we finally were able to produce a decent sand core.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiRnAjeJim-hS9VrQhcgyFqfjOqVja3OaJQ2MWMzVxhoHACVsT9R5pJY9lfDnDj9zmAC0ywohwDbN3SRownTvpD1-1sBrztWMwfPX7eNU9z-F38sA-rQCBI1EOhogupzdzO_jpSuIgpO-k/s1600/08+Broken+Sand+Cores.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="384" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiRnAjeJim-hS9VrQhcgyFqfjOqVja3OaJQ2MWMzVxhoHACVsT9R5pJY9lfDnDj9zmAC0ywohwDbN3SRownTvpD1-1sBrztWMwfPX7eNU9z-F38sA-rQCBI1EOhogupzdzO_jpSuIgpO-k/s640/08+Broken+Sand+Cores.jpg" width="640" /></a></div>There were multiple problems with the core boxes and I didn't want to do anything drastic that would destroy the core box. Making another one would definitely be well beyond my capabilities. Finally, I took the plunge and ran the two halves of the split-core box through the band-saw to cut off a large chunk of wood that was holding the sand core in place. I then cut and screwed a piece of Baltic Birch plywood in place of the two chunks of wood that we cut out. I now had a core box that would release the sand core! At the same time, I cut another piece of Baltic Birch playwood to fit on to the other side of core box so that it would withstand the rigours of ramming core sand into the box. We were ready to start producing sand cores. Or so I thought. <br />
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I produced 8 sand cores (I numbered them "1" to "8"!). After Sand Core #2, I cut off half of the box that produces the bottom core print (after nailing it to the Baltic birch plywood) so that it would release easier. Each time I had to shave a bit-off-here and a bit-off-there. Finally, with Sand Core #8, I got my first perfect (well almost perfect) sand core. Here's what Sand Core #8 looked like with the pattern alongside. You can readily visualize the "hollow" that the sand core will make inside the mold and where the sand core is going to be kept in place by the hollows made by the yellow core prints. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcAjBew6Oo_3BrsFnaAiv3C196dReb1UqrMoa6ZmcuhFAIkKXf7-cXbt1yEMLjBhwfN6R_mhHW0MlvWps1pQuc0ibLDu3Q41ASJmV6JXfHkCW1ADeYbw3B_FJo7n_C62zWvxuQ74ql5rY/s1600/09+Sand+Core+w+Pattern.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="494" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcAjBew6Oo_3BrsFnaAiv3C196dReb1UqrMoa6ZmcuhFAIkKXf7-cXbt1yEMLjBhwfN6R_mhHW0MlvWps1pQuc0ibLDu3Q41ASJmV6JXfHkCW1ADeYbw3B_FJo7n_C62zWvxuQ74ql5rY/s640/09+Sand+Core+w+Pattern.jpg" width="640" /></a></div>Now it was time to go into mass production. I wanted to produce 12 sand cores and I only had one - Sand Core #8. I next gave all parts of the core box a good coat of yellow paint and one coat of spar varnish. Punched in some "witness letters" so that I could know what parts of the core box went where. So we were off to the races - ready to produce sand cores. <br />
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Yeah, right! Each time I produced a sand core, it wouldn't release easily out of the mold. I had to wiggle the two main halves of the core box and the sand core. There was usually a bit that broke off somewhere. Each time it was shave-a-bit-off-here and shave-a-bit-off-there. After another 8 tries, I ended up with 6 sand cores that were reasonably decent.<br />
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And here's the bits and pieces of the core box, along with Sand Core #1 - the second lot.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhdphLIoA2dqBLwwsjNVBXFXM31llIHvAxZGKxdlkaOfZHXoATNZnRUggHsZlhlArMzXLE-aoIHLPWfpPcc_uNv3hF56uivH1suLjsKhZcoG8zTnTtd50FOqTFsDQFSQEzM5JFCmc30VnE/s1600/10+Sand+Core+Front+View.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhdphLIoA2dqBLwwsjNVBXFXM31llIHvAxZGKxdlkaOfZHXoATNZnRUggHsZlhlArMzXLE-aoIHLPWfpPcc_uNv3hF56uivH1suLjsKhZcoG8zTnTtd50FOqTFsDQFSQEzM5JFCmc30VnE/s640/10+Sand+Core+Front+View.jpg" width="562" /></a></div><br />
You can definitely see the complexity of the lines on the inside of the two halves of the split-mold. The lines go in multitudinous directions which result in hidden undercuts. that hold the sand core in the core box.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiu3pXOr0uGgjAup7dYiUGlbP_TXfKWuCjYePfY7eBh2d2vq5LrTNipbmKXBWRbZDtmPLxMnkeoSQvpDd9tDdglWAaa7IGNTc4b9L97Cn1u1FKQNZHDq8J8IHhTeBvAGJAdojWKg4NXNCQ/s1600/11+Sand+Core+Top+View.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="626" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiu3pXOr0uGgjAup7dYiUGlbP_TXfKWuCjYePfY7eBh2d2vq5LrTNipbmKXBWRbZDtmPLxMnkeoSQvpDd9tDdglWAaa7IGNTc4b9L97Cn1u1FKQNZHDq8J8IHhTeBvAGJAdojWKg4NXNCQ/s640/11+Sand+Core+Top+View.jpg" width="640" /></a></div><br />
Short of a major re-manufacture, we'll stick with the wiggling routine as we only have 6 more sand cores to go.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEitiR9-9UWojJCNEu0ebxd4fCWRATyoe9BtRuEMvycCTYndJmIBX3067Fdh3BN4N9L0tG60_gAua1XROxVJH27j4Erf0NE5qZaD56A_IvsDLcnk9HfheTuYw6rR8tjDpQHivkIq4ys-6l4/s1600/12+Sand+Core+Back+View.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="630" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEitiR9-9UWojJCNEu0ebxd4fCWRATyoe9BtRuEMvycCTYndJmIBX3067Fdh3BN4N9L0tG60_gAua1XROxVJH27j4Erf0NE5qZaD56A_IvsDLcnk9HfheTuYw6rR8tjDpQHivkIq4ys-6l4/s640/12+Sand+Core+Back+View.jpg" width="640" /></a></div>Only 6 more to go and we're off to the iron foundry. But first we have to test the sand cores to make sure they fit into the green sand mold. That's up next.Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2481033622229007011.post-76547769013016905142011-12-14T19:04:00.000-08:002011-12-14T19:08:13.540-08:00Baggage Car Bronze Striker Plate - We Test The Pattern<div class="separator" style="clear: both; text-align: center;"></div>After a whole series of gluing the bits and pieces together with epoxy glue, then adding fillets - again with the epoxy glue, we were ready to paint the whole pattern to make sure that we had a relatively flat surface with no indentations that would tear out the sand when we made the mold. Here's some shots of the pattern compared to the original bronze striker plate. This is a front-end view. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjnLI9-WSrrnbnBPh-f62n3n_iejo8pKset5KBO875eZxtAHuX_ZF69-Kn8XsMelJLYfksCKUclPNX2jtAjW79_YsqGLU23oW-Cy6lGL9sq5JJn9-uXIHFy0ks6iQSXeVPMxJR0cWks_nM/s1600/Dsc03110.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="324" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjnLI9-WSrrnbnBPh-f62n3n_iejo8pKset5KBO875eZxtAHuX_ZF69-Kn8XsMelJLYfksCKUclPNX2jtAjW79_YsqGLU23oW-Cy6lGL9sq5JJn9-uXIHFy0ks6iQSXeVPMxJR0cWks_nM/s640/Dsc03110.jpg" width="640" /></a></div>And here's a view of the back.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjR-aAm_Py7D6lHjrAivapsvr-81C4YE-r4VdQNyLPYKCAkjjbTZirVN3wOlrJuixCk2Jzs5kGrT2eRFKjaBliAvtMzAcvQIEjoWd6mOCpSRSxKSOCDD7PqILJeM2tZ8ltlbNhi_Hkrb7w/s1600/Dsc03111.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="310" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjR-aAm_Py7D6lHjrAivapsvr-81C4YE-r4VdQNyLPYKCAkjjbTZirVN3wOlrJuixCk2Jzs5kGrT2eRFKjaBliAvtMzAcvQIEjoWd6mOCpSRSxKSOCDD7PqILJeM2tZ8ltlbNhi_Hkrb7w/s640/Dsc03111.jpg" width="640" /></a></div>And here's where we take a look at the innards of the pattern.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj5Zr7f0RAvCTXnUUaC0y6SQvC2bEi4Xt3iQncF40-ZINEPzX05pvPVQDwd3IDkFOE3TPUredbi6bBLb_QbzEX2lUd5WcSNpcCQR5gGK9nhw2Ib37P738kO9yNPvxTHVU8NMeG8q-jhpF0/s1600/Dsc03112.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="352" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj5Zr7f0RAvCTXnUUaC0y6SQvC2bEi4Xt3iQncF40-ZINEPzX05pvPVQDwd3IDkFOE3TPUredbi6bBLb_QbzEX2lUd5WcSNpcCQR5gGK9nhw2Ib37P738kO9yNPvxTHVU8NMeG8q-jhpF0/s640/Dsc03112.jpg" width="640" /></a></div>Before we take a pattern to the foundry for casting, we want to make sure that the pattern will produce a good mold. So I trucked a bucket of my green sand into Science & Tech last Saturday, along with a small flask (cope and drag), and my mold-making gear. With the help of young Tim Y, I rammed the green sand around the pattern, separated the cope from the drag and pulled the pattern out of the drag.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsxsfP69KgZDcDPskZ38iUZykwly1mpxnzW1vQ-MdNN1rxydygfFdE0tqnVXPBG_qcRbaaUXtmVgzIZiPoHGQWB0LZElYuVhfKwiXEABTC9GjhU9MtLLB8QuiHDwUaC3i-QNwYC-bE1Nk/s1600/Dsc03109.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="426" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsxsfP69KgZDcDPskZ38iUZykwly1mpxnzW1vQ-MdNN1rxydygfFdE0tqnVXPBG_qcRbaaUXtmVgzIZiPoHGQWB0LZElYuVhfKwiXEABTC9GjhU9MtLLB8QuiHDwUaC3i-QNwYC-bE1Nk/s640/Dsc03109.jpg" width="640" /></a></div><br />
Voila - a nice clean mold. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi4cZcftnAOZKyDnsjDlmx4F-p0BvqicnbE36K6bV3UcWmjbtychEF6vM13xa9WjN3_AQx2fnOXT2SCvst2BsZaSoeHSXa7_JE3iVIdRT6dILAqmUWZCzQlVWD2fVBqusR_e0cNBCVXubM/s1600/Dsc03113.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi4cZcftnAOZKyDnsjDlmx4F-p0BvqicnbE36K6bV3UcWmjbtychEF6vM13xa9WjN3_AQx2fnOXT2SCvst2BsZaSoeHSXa7_JE3iVIdRT6dILAqmUWZCzQlVWD2fVBqusR_e0cNBCVXubM/s640/Dsc03113.jpg" width="426" /></a></div><br />
We're going to do it all over again next Saturday only this time we'll add some sprues, gates and risers as I think I'm going to have to be the mold-maker on this project. If I had a foundry, I could even be the foundryman.<br />
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PS - Many thanx to Jim L. for his photography expertise.Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2481033622229007011.post-43061882860065099542011-10-30T17:51:00.000-07:002011-12-14T19:07:32.573-08:00Baggage Car Bronze Striker Plate - Making The PatternNow here's a real challenge for you pattern makers. This is a photo of a bronze striker plate from the end-doors of Bytown Railway Society's ex-Canadian National Railways baggage car. When first examined, it had a couple of cracks in it, some broken pieces, to say nothing of the fact that it had been whacked into place and out of shape some decades ago when it was first installed - who knows when? Here's a photo of the "front" of the striker plate. <br />
<div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKE4vnQfhiSnK-0JKR3fxD9OLc_jBb5cLH-CZ9fXLJVPKDSvpfB0EIK3sFrzTBdr2SzgQonfWi0mVlMYSidbvVNS8Pwt3_jLtH5JeFq1V4C_0Y93VOk6Af-QjVdmDoIYnaYmUhAM3xn48/s1600/Dsc04701.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="282" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKE4vnQfhiSnK-0JKR3fxD9OLc_jBb5cLH-CZ9fXLJVPKDSvpfB0EIK3sFrzTBdr2SzgQonfWi0mVlMYSidbvVNS8Pwt3_jLtH5JeFq1V4C_0Y93VOk6Af-QjVdmDoIYnaYmUhAM3xn48/s640/Dsc04701.jpg" width="640" /></a></div><div class="separator" style="clear: both; text-align: center;"></div><br />
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It's a fact with bronze and brass that you never know when the bronze will melt. In fabricating the accelerator for the propane burner for my backyard foundry, I quickly discovered that some brass melts almost exactly at the same temperature as the silver solder I was using. I've got about 4 of these parts that melted just like a wax candle when I applied the heat. It all depends on what the brass or bronze has been alloyed with which determines the melting point of the brass.<br />
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Here's a photo of the "back" view of the striker plate. You can see that the striker plate is built up from two surfaces - a flat horizontal surface (the piece with the two holes on each side), and a flat vertical surface (the piece with the two holes closest to you). Notice the two "wings" on each side. Without these two wings, it would be relatively simple to make a green sand mold. However, it's these two wings that will be the challenge for this kind of casting.<br />
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To continue with our "tour" of the striker plate, here's an inside side view which gives shows the "latch" piece (the wedge on the left) that the door latch latches onto. The latch piece on the other door is on the right side. So our design of the pattern will incorporate a "universal" latch piece for both a right-hand and left-hand door opening.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhdPBp1141ZyL2h5pjowgKJjVsebQyvrmEjpvfnEBBL_wlm6JBxa7M9VlLDzTS7xcBlY_eVdTv9Bvdvj1FBX8lvqNNYiB3JMAPmMRWBTPz7ACdkKVTBrIJkaGRxLsaJCrSj78lNjQmDpNI/s1600/Dsc04703.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="308" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhdPBp1141ZyL2h5pjowgKJjVsebQyvrmEjpvfnEBBL_wlm6JBxa7M9VlLDzTS7xcBlY_eVdTv9Bvdvj1FBX8lvqNNYiB3JMAPmMRWBTPz7ACdkKVTBrIJkaGRxLsaJCrSj78lNjQmDpNI/s640/Dsc04703.jpg" width="640" /></a></div><br />
<div class="separator" style="clear: both; text-align: center;"></div>Here's another shot of the above photo but taken from the right side. This photo really shows how the part has been bashed and smashed over the decades.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcTgtg-DGtiDL7gm2JPBPvD_T-g9AX4MhAqtNjH_oLcG9l-0OJpbYDcABhvBoc7Vra2On5loaZA1H_AJSZwENtGGxn2iFgJnHNQcETrx6W3wFvTvNixKdZKlvgQ0RccwyPosvgbcTCTfI/s1600/Dsc04704.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcTgtg-DGtiDL7gm2JPBPvD_T-g9AX4MhAqtNjH_oLcG9l-0OJpbYDcABhvBoc7Vra2On5loaZA1H_AJSZwENtGGxn2iFgJnHNQcETrx6W3wFvTvNixKdZKlvgQ0RccwyPosvgbcTCTfI/s640/Dsc04704.jpg" width="420" /></a></div><br />
In trying to weld the cracks on this striker plate, the bronze started to vapourize which didn't improve the situation at hand. So, I was handed the piece and asked to make a pattern for some castings. Since there are two doors at each end of the baggage car, I wanted to see if I could get some accurate dimensions from the other striker plate at the opposite end of the car. After removing and examining this second piece, while it was in better shape than its mate, it wasn't much better. So it was a matter of cut- file-and-fit repeated several times until we got the pieces to fit together. Here's a photo of some of the bits-and-pieces before we glued them together.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbKJjypMAYy-eRKDtu_jqQf3rG-aXCR-h6X-g5ytGekjJwwRVkH2IBX6NHIRTAAszSFXWtLpkM-6smh_YKv-AgJIGU-xgYP_k9i9KWd9OunS_WmmLLauJtm3xZdA2FghRV6VoRCeVyRqk/s1600/Dsc04706.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="528" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbKJjypMAYy-eRKDtu_jqQf3rG-aXCR-h6X-g5ytGekjJwwRVkH2IBX6NHIRTAAszSFXWtLpkM-6smh_YKv-AgJIGU-xgYP_k9i9KWd9OunS_WmmLLauJtm3xZdA2FghRV6VoRCeVyRqk/s640/Dsc04706.jpg" width="640" /></a></div><br />
<div class="separator" style="clear: both; text-align: center;"></div>And here's a couple of shots of the bits-and-pieces glued together. That belt sander in the woodworking shop saw double-duty these past few weeks. Needless to say a few of our bits-and-pieces ended up in the garbage pail when we sanded off a bit too much. <br />
<div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEho96Ue-NfSc6rmRO7DDp-QTENuItISRZU5CI-tOY0B4sBvlTdeqaS7PFYVENyjvkqljpJj8-kXxWDADrcWsoDqpm16g84qP7hOY0XLI9v4b2rU4r2iWzzWcxtH-ZXQNhZ5owPOIRgvytg/s1600/Dsc04707.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="278" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEho96Ue-NfSc6rmRO7DDp-QTENuItISRZU5CI-tOY0B4sBvlTdeqaS7PFYVENyjvkqljpJj8-kXxWDADrcWsoDqpm16g84qP7hOY0XLI9v4b2rU4r2iWzzWcxtH-ZXQNhZ5owPOIRgvytg/s640/Dsc04707.jpg" width="640" /></a></div><br />
The material we used for the pattern is 1/8" 3-ply Baltic birch plywood. At first we were going to use wood glue to stick all the bits and pieces together but then we realized that the pattern probably wouldn't stand up to the heavy-duty ramming required when we made the green-sand mold. So, while we used wood glue to temporarily stick the pieces together, we used epoxy glue to make sure that everything would hold up to some rough abuse.<br />
<div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgT5jqlnngweoDKMbEu2AguilWhOqPuBmXsiXmGDDP4VwgVK5R1bXLBt8IXV1CAzgXfhT1Y9HPSg45B18XoUSl9VIz0nMogr-kZilpuWiRKNQ6QhL5ae3ivWn9QDHyT6OTmD7Zy_uCaRiU/s640/Dsc04708.jpg" width="400" /></div><br />
In any pattern, we have to consider three things -<br />
<ol><li>Shrinkage of the metal when it transforms from molten metal to a solid, </li>
<li>Draft (or slope to the sides) so we can extract the wooden pattern from our sand mold, and </li>
<li>Fillets (or rounded edges where two pieces of wood fit together) to reduce the "tearing" of the metal as it goes from a molten mass to a solid. </li>
</ol>We made our pattern a bit oversize to take care of the first issue, added some "slope" to the sides to take care of the draft, and used epoxy glue to create fillets where two pieces of wood joined together. The darker parts on the pattern is epoxy glue. In addition to creating fillets, the epoxy glue has added extra strength to the whole pattern. Hard to see from this angle but they do create nice rounded fillets. <br />
<div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhU0tROWogetTTHrEAjOShN4fetiaHfrXJuu22X7MCNC8AyQsfLMQp6YIg9mOWSFipUXe4XFLOlPnbLpj4jhCIkoldjHovbfWAEJFZ2TSr8E52lFfdNUi1GSp_N5ENEqPNvw_fsCt2psus/s1600/Dsc04710.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="284" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhU0tROWogetTTHrEAjOShN4fetiaHfrXJuu22X7MCNC8AyQsfLMQp6YIg9mOWSFipUXe4XFLOlPnbLpj4jhCIkoldjHovbfWAEJFZ2TSr8E52lFfdNUi1GSp_N5ENEqPNvw_fsCt2psus/s640/Dsc04710.jpg" width="640" /></a></div><br />
Using epoxy glue required gluing the bits-and-pieces together over several days as the old-fashioned 5-minute epoxy has disappeared from the store shelves. All you can get now is a 24-hour epoxy which takes about 48 hours for the glue to set - sometimes even longer - and cure. <br />
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Here are some "before-and after", or rather, "original-and-pattern" shots taken from various angles.<br />
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The difference is quite visible in the above shot, isn't it. We aren't going to include the holes in our pattern as it will be easier to drill the holes after the part has been cast. Here's a side view of the two.<br />
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And an end view. You can see how we've added draft (slope) to the pattern. This will help in extracting the pattern from the green sand when we make the mold. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhx-SWv_1Wwa_bPgkqD1glMbUhI-EnYWyJuXW8N2kny97qPWEMLDvvsQzheOC4N2e7ZT5pyKRExePkzkrXq7xQd2azH0c3zA6rIHxcPsFQ52VaxKAcdk-0GqdfAF3yzf2NO6oiHS9QNi64/s1600/DSC04715.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="588" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhx-SWv_1Wwa_bPgkqD1glMbUhI-EnYWyJuXW8N2kny97qPWEMLDvvsQzheOC4N2e7ZT5pyKRExePkzkrXq7xQd2azH0c3zA6rIHxcPsFQ52VaxKAcdk-0GqdfAF3yzf2NO6oiHS9QNi64/s640/DSC04715.jpg" width="640" /></a></div><br />
We've still got to add the latch part to the pattern but we'll have that done for next week. We'll then spray on a couple of coats of paint to make sure we don't have any "ripples" between the glued joints, followed by a couple of coats of lacquer. After that we'll "test" the pattern by making a mold in our green sand. That will be the real test!<br />
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Tony Z from my "basement machine shop" group gave me the name of a person who has a backyard foundry who does castings in brass and bronze. We'll have to see if he would like to do a casting or two, eh!?<br />
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PS - Many thanx to Jack L for his photography expertise.Unknownnoreply@blogger.com2tag:blogger.com,1999:blog-2481033622229007011.post-89493745843328098992011-06-05T04:18:00.000-07:002011-12-30T06:27:55.274-08:00Screw The Core Boxes, eh!!<b><u>Screw The Core Boxes!!</u></b><br />
One of the tricks-of-the-trade I learned with the Sodium Silicate/ CO2 experience was a better way to make core boxes. My first attempts resulted in a core box built in two pieces with wooden pegs to join the together - the same way you fasten the two halves of a split-pattern together.<br />
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That was a complete failure - for two reasons. Firstly, trying to pull apart two halves of a 3-sided core box (one end, half of one side and half of another side) didn't work. The sand core got stuck in the core box and had to be broken out. Secondly, without realizing it (remember this was my first experience making sand cores!), one of the core boxes had an extremely large "undercut". I ended up with a solid chunk of sand stuck in this angled core box. The only way to get the sand core out was to dig it out with a screwdriver. So much for that sand core!<br />
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Then I hit upon the idea of fastening the sides of the core box together with screws. This way, when the sand core had solidified, it was a simply matter of undoing the screws.<br />
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The solidified sand core easily released from the sides of the core box as each pair of screws was undone. This way, I could give the sand core an extra couple of shots of CO<span style="font-size: xx-small;">2</span> with all 6 sides of the sand core exposed. <br />
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<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpQvkF1pRxOLrdAFGZwcLtcFrl4lfBHi0-MKevLRPf-ZZIGA7XA4H-Q7qAmaLZVcksxQas4JdmLoZ2AFyGmLX881aMwbaecwQKWCiiYE4cAejqICxyWAEjI9h1pQugevoqT5fD9Y_VmMY/s1600/Img_1701.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="502" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpQvkF1pRxOLrdAFGZwcLtcFrl4lfBHi0-MKevLRPf-ZZIGA7XA4H-Q7qAmaLZVcksxQas4JdmLoZ2AFyGmLX881aMwbaecwQKWCiiYE4cAejqICxyWAEjI9h1pQugevoqT5fD9Y_VmMY/s640/Img_1701.jpg" width="640" /></a></div><br />
All in all, a great first-time experience. No muss, no fuss, no cleaning up my wife's oven, eh!?Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2481033622229007011.post-90260773805043474602011-02-13T05:52:00.000-08:002011-06-04T16:27:34.518-07:00Casting The Patterns - Another Day At Alumaloy CastingsThe day had finally arrived when I had the patterns ready after a bit of fine tuning and Alumaloy Castings Inc in Toronto were going to pour some #317 aluminum alloy. A few other stars and planets had also come into alignment for some personal business that warranted the trip from Ottawa to Toronto. In testing the patterns in my own green sand, I had discovered a couple of "flaws" that I wanted to correct which also led to some delays in the final casting. In hindsight, these are "lessons learned" for my next patterns.<br />
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The master mold-maker was Marco Stabilini, one of the principles of Alumaloy. Marco's been in the aluminum business since he was knee-high to a grasshopper as his father had started the business many decades ago.<br />
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The first step was to select a flask (cope and drag) large enough to hold the two patterns. The drag was set bottom-side-up on a mold board. Alumaloy is a production facility so they have the specialized equipment for large-production green sand mold making as we shall see in the photos below.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSkwofyCdnZ40mU6jeCeG1VZLG9K4BlLxWOfWBFm-AXVYuSXUka_cDI0TjzDjAw4CqoKRC5Oot_BuNMQLfbYAEwJ0uG0NJwN79z5SSQBu_tn_2DutdW6L15kNVsjXmBVvRxCd442rSQZ8/s1600/IMG_1942.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSkwofyCdnZ40mU6jeCeG1VZLG9K4BlLxWOfWBFm-AXVYuSXUka_cDI0TjzDjAw4CqoKRC5Oot_BuNMQLfbYAEwJ0uG0NJwN79z5SSQBu_tn_2DutdW6L15kNVsjXmBVvRxCd442rSQZ8/s640/IMG_1942.JPG" width="640" /></a></div>That "block" of wood between the two patterns will form a hollow "gate". Aluminum cools as it shrinks. Without the gate, the shrinkage will occur within our hollow mold and distort the pattern. Along with a large cylindrical riser, the gate will act as a reservoir that allows additional molten aluminum to flow into the mold so that shrinkage will occur outside the mold.<br />
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As with any mold making, the patterns were next dusted with parting powder. The fine white talc keeps the green sand in the drag from sticking to the green sand in the cope and to the pattern. It allows us to readily separate the cope from the drag.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhZ8TBx4KZokzZQnNcVBS2A2nlO6U_R4XiVtfOf6f6nWuz_hJcag9bl_kjaiSxLmpDp2MBReVa1hT750OXeEcUKewrU9wxXL646EgNWJ5BNVP2s5Y8svPVsasmyOx-heNgiEi-nh4d2ofA/s1600/IMG_1943.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhZ8TBx4KZokzZQnNcVBS2A2nlO6U_R4XiVtfOf6f6nWuz_hJcag9bl_kjaiSxLmpDp2MBReVa1hT750OXeEcUKewrU9wxXL646EgNWJ5BNVP2s5Y8svPVsasmyOx-heNgiEi-nh4d2ofA/s640/IMG_1943.JPG" width="640" /></a></div>Once the dust had settled, Marco riddled (to the uninitiated, that's "screened") some green sand over the patterns. Riddling the sand ensures there are no lumps or unwanted pieces lying against the patterns so that we have smooth castings.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjhK7483dju7o4hJH5SLPsGhYpaVUgXeG-F0LNYzImn5Ve5pJQIgaOcrz1mxf0c2DjBoDRxt73bYmSRTW4a9UjM8W_QYUnSvY2jCmyBv6vMkKM1VCPAi464GYlOEpLEafpwfsjVod4vfk0/s1600/IMG_1944.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjhK7483dju7o4hJH5SLPsGhYpaVUgXeG-F0LNYzImn5Ve5pJQIgaOcrz1mxf0c2DjBoDRxt73bYmSRTW4a9UjM8W_QYUnSvY2jCmyBv6vMkKM1VCPAi464GYlOEpLEafpwfsjVod4vfk0/s640/IMG_1944.JPG" width="640" /></a></div>With the patterns nicely covered with riddled sand, Marco then filled the drag with more green sand from the hopper above his head. By simply pulling on the lever over his head, he controlled the flow of green sand into the drag. Before ramming the sand, he pressed the sand around the patterns so that the patterns wouldn't move and to make sure that all cavities were tightly filled with sand. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgU85ZjlYNA83dRMkJ1Sez03WatbI_m3LBCgbajb4BVk-pivCg6LDZN3jfEvGS-ZtQz1CEqgMOYC1_fknBJZ2HiCrdUSBfg3zrQtl6_vqVKUKCU7TWJTc8ZAKLski0PlN4-t-L_d7U9OVk/s1600/IMG_1947.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgU85ZjlYNA83dRMkJ1Sez03WatbI_m3LBCgbajb4BVk-pivCg6LDZN3jfEvGS-ZtQz1CEqgMOYC1_fknBJZ2HiCrdUSBfg3zrQtl6_vqVKUKCU7TWJTc8ZAKLski0PlN4-t-L_d7U9OVk/s640/IMG_1947.JPG" width="640" /></a></div>As he filled the drag with sand, Marco rammed the sand tightly with the air ram. This ensured there were no lightly-compacted spaces in the drag. The air ram hopped around the drag as he went around the edges. <br />
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<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSuaksvFGo24fAT7CGrctosvF37XMhe35FAazHixtAdYqhBxNKiNGXQZD_N2i_eO8TCuuB1yi-zetC00Oe37mn9W_lY4uOuBGZPL05MsYnIT33SY2IskVYzl48CRsyUPO90mXghRRGFnI/s1600/IMG_1949.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSuaksvFGo24fAT7CGrctosvF37XMhe35FAazHixtAdYqhBxNKiNGXQZD_N2i_eO8TCuuB1yi-zetC00Oe37mn9W_lY4uOuBGZPL05MsYnIT33SY2IskVYzl48CRsyUPO90mXghRRGFnI/s640/IMG_1949.JPG" width="640" /></a></div>Once he was satisfied that the drag was full, he placed another mold board on the drag, moved the squeeze plate into position and squeezed the bejesus out of the green sand. The sand sank at least another inch as the pressure was applied.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj07uX_zvbY_ee5I5aJ-M7Mq_dp6iVty2tAbuk4O21opwEnjPXrsTVX8xOlf-Ph__Xof54eFt5ZKxvd2vbWeI9x44nUCO5V3pXUJudDSlZLsqmNbwbO_lFH_gT3AVkrZ70_Tubqsyv8Et8/s1600/IMG_1951.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj07uX_zvbY_ee5I5aJ-M7Mq_dp6iVty2tAbuk4O21opwEnjPXrsTVX8xOlf-Ph__Xof54eFt5ZKxvd2vbWeI9x44nUCO5V3pXUJudDSlZLsqmNbwbO_lFH_gT3AVkrZ70_Tubqsyv8Et8/s640/IMG_1951.JPG" width="640" /></a></div>With the drag part of the mold now finished, Marco and another employee turned the drag over - right-side-up.<br />
<div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEioaOmqNkOgsXOVnAjljhVQ1PUzZKMcO4Tm4ITM7u3YxW3shyphenhyphenH958Ur-L__0UnqtVi4g14QyuV2YPy16aH57c1Rz-cWEUpaEcci_mMI16XMQ4oHDA3Gdi2CONgRGPO2hGgJKYwgHZL71Zg/s1600/IMG_1952.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEioaOmqNkOgsXOVnAjljhVQ1PUzZKMcO4Tm4ITM7u3YxW3shyphenhyphenH958Ur-L__0UnqtVi4g14QyuV2YPy16aH57c1Rz-cWEUpaEcci_mMI16XMQ4oHDA3Gdi2CONgRGPO2hGgJKYwgHZL71Zg/s640/IMG_1952.JPG" width="640" /></a></div> Paying close attention to the outline of the patterns, Marco then scraped and brushed green sand away from the edges of the pattern. There was one part to each pattern where the green sand had to be molded down. The darker areas in the photo below show the areas that received extra attention. You can clearly see how the block of wood will form a hollow gate between the two patterns. This gate (filled with aluminum) will be sawed off on the bandsaw during the final steps. <br />
<div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQzEVJsQSa3_PY3rxhyphenhyphen35jItgW4siAhyphenhyphenGFQ89FtOggvqCC7UAQf-0_6uHEBzVecGQjFyvN8kbNv8RxagG1trke_SN6xz_dS1yuJbjOQr4HM9XFC7vhtr0lk-E_8uVXv-Lhqj1m24Wqc1k/s1600/IMG_1956.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQzEVJsQSa3_PY3rxhyphenhyphen35jItgW4siAhyphenhyphenGFQ89FtOggvqCC7UAQf-0_6uHEBzVecGQjFyvN8kbNv8RxagG1trke_SN6xz_dS1yuJbjOQr4HM9XFC7vhtr0lk-E_8uVXv-Lhqj1m24Wqc1k/s640/IMG_1956.JPG" width="640" /></a></div>More parting powder was shaken onto the top so as to ensure that the cope didn't stick to the drag. As Marco said, the role of parting powder is to stop sand from sticking where you don't want it. Our patterns are "split patterns". That is, there's a bottom part that is molded in the drag and a top part that is molded in the cope. The top part fits into the bottom part with two holes and wooden dowels that match up to each other. You can see how the top part has been fitted to the bottom part in the photo below. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDBmSzaD2-_7Fu2O3uJN7uNz2SF_ZIO6yuYgamFmib6BZPkdkA1f4lrd0g1accDG6rZuZqfV7p8qpvjLQtswl57pjHUgIOZEFcXpOXNrV4TVMhCP_xPJBrKknb2h5diHomthaeDZz1FuI/s1600/IMG_1961.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDBmSzaD2-_7Fu2O3uJN7uNz2SF_ZIO6yuYgamFmib6BZPkdkA1f4lrd0g1accDG6rZuZqfV7p8qpvjLQtswl57pjHUgIOZEFcXpOXNrV4TVMhCP_xPJBrKknb2h5diHomthaeDZz1FuI/s640/IMG_1961.JPG" width="640" /></a></div>On closer examination of the space between the top of the two patterns, Marco decided to "mold up" the space between the two as leaving this space to be filled during the regular filling and ramming of the cope would leave a weak spot. This weak spot might disintegrate and loose sand would flow into the mold, thereby corrupting the casting with sand holes.<br />
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You can see the alignment pins in the drag in the the front of the photo below. It is these alignment pins (one on each side) that ensures that the cope will fit exactly into the correct position on the drag after the pattern has been removed from the mold. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjL4wqBIMcoBCMOr2x9WhebRZ1KzIzgDbRzHk4LG0FNM_jvxN1QtrtnbnA6P4M9LDEoPzIM2bvqVITiBaqV2Y1Ms6Y1ESDI1ZmWadtyxX1-F1MeI0UCByw_p8KC-fGmXx_lY8AGU0iR3m8/s1600/IMG_1964.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjL4wqBIMcoBCMOr2x9WhebRZ1KzIzgDbRzHk4LG0FNM_jvxN1QtrtnbnA6P4M9LDEoPzIM2bvqVITiBaqV2Y1Ms6Y1ESDI1ZmWadtyxX1-F1MeI0UCByw_p8KC-fGmXx_lY8AGU0iR3m8/s640/IMG_1964.JPG" width="640" /></a></div>With the top of the drag finished off and dusted with parting powder, the cope was next fitted over the alignment pins and onto the top of the drag. Marco then set a hollow ceramic cylinder on top of the gate and inserted a sprue cutter (the hollow brass cylinder in his hand). The cylinder acts as a riser which ensures that the mold is completely filled with aluminum. It also allows any gas that dissipates from the molten aluminum to rise to the top. As the molten aluminum is poured into the sprue, it flows through the gate and into the mold. As the mold is filled, the aluminum rises in the mold and into the riser. As the molten aluminum cools, it shrinks. At this point, more molten aluminum is poured into the riser.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgT2huBqMMD7fvRwgeN47fPNxRtAFyoTu7-i9cagMI8XZPTruOxQLBDV-DXmhUIYta_nondeiZEV7T0PfsH9skaxD853I8E6LkUeY0Gglgogs6mSKjTIRT6HajHXsarMGpLw8IztDBudx8/s1600/IMG_1969.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgT2huBqMMD7fvRwgeN47fPNxRtAFyoTu7-i9cagMI8XZPTruOxQLBDV-DXmhUIYta_nondeiZEV7T0PfsH9skaxD853I8E6LkUeY0Gglgogs6mSKjTIRT6HajHXsarMGpLw8IztDBudx8/s640/IMG_1969.JPG" width="640" /></a></div>Green sand was next riddled over the top of the dusted patterns, tamped into place, more sand added, rammed and then the top tamped smooth.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgTuKGL3yfqxHUAsvpdTuD9JBhJJCsaMlXYWB6BijghTqhadtaYWfAHdV_BFrOHO4m5bixEC7NA8w8H59aHGe8OgzsH8fDr-ANiBbrWLrKWqwn_uKWtmeMsYncpnNrUNBantESKXykIkDg/s1600/Img_1970A.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgTuKGL3yfqxHUAsvpdTuD9JBhJJCsaMlXYWB6BijghTqhadtaYWfAHdV_BFrOHO4m5bixEC7NA8w8H59aHGe8OgzsH8fDr-ANiBbrWLrKWqwn_uKWtmeMsYncpnNrUNBantESKXykIkDg/s640/Img_1970A.jpg" width="640" /></a></div>Next the cope was lifted from the drag with the top half of the pattern staying in the cope and the bottom pieces still in the drag. The dowels in the top half of the pattern were loose enough that the pattern split very evenly. The cope was placed on a stand that allowed easier access for finishing off the top half of the mold. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhXRxD-SLJVyCCQ_6F3CWj42EAxOAbrr9s0W0B84prI_DURk1ABwhgnKfmemLCFI27FfKtd6DuCCp70BXYcufqhPDG71NdtDcEBQIfAWBo8DAcYVGpWM5KGro3FkTrAwZgtI_5uBxwk0uQ/s1600/IMG_1978.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhXRxD-SLJVyCCQ_6F3CWj42EAxOAbrr9s0W0B84prI_DURk1ABwhgnKfmemLCFI27FfKtd6DuCCp70BXYcufqhPDG71NdtDcEBQIfAWBo8DAcYVGpWM5KGro3FkTrAwZgtI_5uBxwk0uQ/s640/IMG_1978.JPG" width="640" /></a></div>The next task was to remove the top half of the pattern from the cope. Rapping the dowels gently, the top halves of the patterns came out cleanly from the mold. (Notwithstanding that the flask (cope and drag) are made from aluminum, that's about 100 lbs of green sand in the cope! Not exactly a light load, eh!?)<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEizQVw4dzTl3kcDbE-xcbMJ5v329uwqBQ1zq_wKeD7WQcTMA6kDk344wLHeJC1nnfLPqGRQl6f0z_WFoMwTJhSSLJRv-fLogfjrOoKXjFXTjgwS4f5Y-wEcUq81C4M6VcfnaE6tRpQs7EA/s1600/IMG_1982.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEizQVw4dzTl3kcDbE-xcbMJ5v329uwqBQ1zq_wKeD7WQcTMA6kDk344wLHeJC1nnfLPqGRQl6f0z_WFoMwTJhSSLJRv-fLogfjrOoKXjFXTjgwS4f5Y-wEcUq81C4M6VcfnaE6tRpQs7EA/s640/IMG_1982.JPG" width="640" /></a></div>The next step was to clean up any loose sand, making sure that it was all blown off the cope, cylinder, and sprue hole, in addition to rounding out the top of the sprue hole.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7m5VqPeB8kba_r7BkHbq9aEkGHZ5tX-1wIRmIOa88ZqQM6gGYVVmZVaACr5P53bqKby3Jt_xw7uCjYSFjAy6GdHPZ3wvw-t5717cXDVaAbN3IfvRB1pVNDaMtyBNXKy0sbiQWOHZlg-4/s1600/Img_1984A.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="242" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7m5VqPeB8kba_r7BkHbq9aEkGHZ5tX-1wIRmIOa88ZqQM6gGYVVmZVaACr5P53bqKby3Jt_xw7uCjYSFjAy6GdHPZ3wvw-t5717cXDVaAbN3IfvRB1pVNDaMtyBNXKy0sbiQWOHZlg-4/s640/Img_1984A.jpg" width="640" /></a></div>With the cope cleaned up, it was now time to focus attention on the drag and removing the bottom half of the split patterns from the sand mold. After blowing loose sand from the top of the drag, Marco then wicked water around the perimeter of the patterns. This was to ensure that the sand didn't break off from the edge of the mold when the patterns were lifted out. Green sand has a specific moisture content which allows the sand to clump and stick together.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2gV-vkyhKjqwsz2eABwjQtGo9gqJ_fd9vsGfM4C-7Dpf7gAaL8_kD3Mte-EKthpTkBrpUZ_l1yKz3P1RP5IZ70CXXO97xj_yaAcUXnjwhyytmp_gQXg7M4shhyphenhyphenZhrQ_8L2h3rtTBolBk/s1600/Img_1989.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2gV-vkyhKjqwsz2eABwjQtGo9gqJ_fd9vsGfM4C-7Dpf7gAaL8_kD3Mte-EKthpTkBrpUZ_l1yKz3P1RP5IZ70CXXO97xj_yaAcUXnjwhyytmp_gQXg7M4shhyphenhyphenZhrQ_8L2h3rtTBolBk/s640/Img_1989.jpg" width="480" /></a></div>And here's close-up of what the drag looks like before the patterns have been rapped and removed. Each one of the two patterns plus the block to form the gate will have to be rapped (tapped) and slowly lifted out. It is this part of the operation that will determine whether the pattern maker has done his job by including enough draft (slope) on the sides of the pattern, there are no hidden undercuts incorporated into the pattern that will lift out the sand and ruin the mold. This is one of the reasons why a pattern should be "tested" separately in green sand before being taken to the foundry for pouring. You can clearly see how the drag was "molded up" between the two patterns. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiVAJm2opvpNkQC_9SpKgZYCTfRjHrAwddinijM_DelSz3wP4cWtYnmzZCEPWa8dlw0o5hOyQtD-KefRRQayBwvePQHTRsc8CfhSoKTeA_FULE2KE-K7YrDpP75kEDGxouHOVo6AMZOkTE/s1600/IMG_1990.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiVAJm2opvpNkQC_9SpKgZYCTfRjHrAwddinijM_DelSz3wP4cWtYnmzZCEPWa8dlw0o5hOyQtD-KefRRQayBwvePQHTRsc8CfhSoKTeA_FULE2KE-K7YrDpP75kEDGxouHOVo6AMZOkTE/s640/IMG_1990.JPG" width="640" /></a></div>First the block that forms the gate is removed and loose sand gently blown off the mold. The block is rapped to release it from the green sand, a screw (inserted onto the end of a piece of wood) is inserted in the hole in the block of wood. When making patterns, these holes should be included in the pattern so as to facilitate lifting the patterns from the mold.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj6920G6ainspvrUvnuDclIGfv8qcrVvDBcptgNu68UTXNOj4X5fke18pLsdV9KgYaWVL8_B764_dU3qBIMUnNfTue-lBV_PEemWtXsj_ZJXLq1omvczUPzwkgbx7sjqd48yGgNfLly0ZI/s1600/IMG_1991.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj6920G6ainspvrUvnuDclIGfv8qcrVvDBcptgNu68UTXNOj4X5fke18pLsdV9KgYaWVL8_B764_dU3qBIMUnNfTue-lBV_PEemWtXsj_ZJXLq1omvczUPzwkgbx7sjqd48yGgNfLly0ZI/s640/IMG_1991.JPG" width="640" /></a></div>With the block of wood now lifted out of the mold, loose grains of sand are blown out of the mold. It may also be the case that the sand may have to be "vacuumed" from the mold. This is done with a piece of 1/2" pipe which has a "T" fitting soldered to the top. A steady blast of air is blown into one side of the "T" which creates a vacuum down the tube. The loose sand is sucked up the pipe and out the other side of the "T" fitting. Removing loose sand is very important at each step as loose sand in the casting creates "sand holes". <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg4igkd2Ah0JRrFmGb14l28EA10zC6xmPWYakQhNrjlOUtpIUQtjbbPkbNTHZVHgbACMCji_xac7Z4mwkzx0rXcbZfh5-AGavE0F3k0cx6zCF_cWje4CWUqnbyEI69h1BoN6sS98YLvv-M/s1600/Img_1993.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg4igkd2Ah0JRrFmGb14l28EA10zC6xmPWYakQhNrjlOUtpIUQtjbbPkbNTHZVHgbACMCji_xac7Z4mwkzx0rXcbZfh5-AGavE0F3k0cx6zCF_cWje4CWUqnbyEI69h1BoN6sS98YLvv-M/s640/Img_1993.jpg" width="480" /></a></div>A channel needs to be cut from the sprue to feed molten aluminum into the gate. Using a molder's spoon, he simply scoops some sand from the gate back to the hole made by the sprue cutter. The loose sand is blown off of the mold. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiHw9HBzt1lyz2n15VyytuoI2lPxRBkOVeRV1_wOigCLdiPhWAuS_CbFmbgOhtvGetaI3csH6L5kUOwPik5Nk5CLwhryUrkX9_6pwYAPYi02aGEQ7gTRnJ9rYN98RZGgz9PWl8b7jnA7To/s1600/Img_1997.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiHw9HBzt1lyz2n15VyytuoI2lPxRBkOVeRV1_wOigCLdiPhWAuS_CbFmbgOhtvGetaI3csH6L5kUOwPik5Nk5CLwhryUrkX9_6pwYAPYi02aGEQ7gTRnJ9rYN98RZGgz9PWl8b7jnA7To/s640/Img_1997.jpg" width="480" /></a></div>Once the block of wood is removed from the mold, the sides of the pattern are rapped - both on top and on the sides - to release it from the mold. This is very critical in ensuring that the patterns can be lifted from the mold without breaking any of the sand from the mold. If this happens, the mold will be finished and we will have to start all over again.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjK2sfmMxJQ6PKUfCneGoml4NEXC8iUXqepjiVdq5ZRvyDhyphenhyphenDX_rFdR55WsOlnNV53piL1uPvn2DFdvQFp1GkGD2B-iewdp9kfSq_xkziUcbBZgJKdJ_ItpR6yvCFlF2XcX9UW2F_h2yhQ/s1600/IMG_1994.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjK2sfmMxJQ6PKUfCneGoml4NEXC8iUXqepjiVdq5ZRvyDhyphenhyphenDX_rFdR55WsOlnNV53piL1uPvn2DFdvQFp1GkGD2B-iewdp9kfSq_xkziUcbBZgJKdJ_ItpR6yvCFlF2XcX9UW2F_h2yhQ/s640/IMG_1994.JPG" width="640" /></a></div>Inserting two screws into the holes provided in the pattern, the first pattern is carefully lifted out of the mold. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjoP2Sk_HwrevHktr19214QRvFlcpQfhN25nehWw4OGG_sjcb7_8B-2xMUdadI6vhAtI-E4p2MAN_SDYCGs9ikRiScT3lTAFZX4kwtPUDihL5wVCHMi1NcNfiPBgUllglAy_hiWtxXM7gI/s1600/Img_2000.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjoP2Sk_HwrevHktr19214QRvFlcpQfhN25nehWw4OGG_sjcb7_8B-2xMUdadI6vhAtI-E4p2MAN_SDYCGs9ikRiScT3lTAFZX4kwtPUDihL5wVCHMi1NcNfiPBgUllglAy_hiWtxXM7gI/s640/Img_2000.jpg" width="480" /></a></div>And the same process is repeated with the second pattern. This is where the location of the screw holes in a pattern becomes very important. If the holes aren't included, or they're put in the wrong place, the green sand can be broken when the pattern is lifted. You can see in the photo below the outline of the mold for the first pattern. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjTBkv5_op9lrpagOWsr6SUiUiOm_WYns_i2f8NqN80hVX-mscZokGtPcRzFOmwfkqyvPpu3txyCdccmfs0VPgNlkakPyiJGbxkIGfg3VIbLQTeXBWM6mn-JeSX0RjzAaLQr5Vr87mVGps/s1600/Img_2001.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjTBkv5_op9lrpagOWsr6SUiUiOm_WYns_i2f8NqN80hVX-mscZokGtPcRzFOmwfkqyvPpu3txyCdccmfs0VPgNlkakPyiJGbxkIGfg3VIbLQTeXBWM6mn-JeSX0RjzAaLQr5Vr87mVGps/s640/Img_2001.jpg" width="480" /></a></div>With the patterns successfully removed, the mold is cleaned up, inspected for loose sand, dusted with parting powder and then lightly sprayed with kerosene. This will help to keep the green sand in place as the sand cores are inserted into the cavities in the mold.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2NTn704niEoRObcrieeg1hTzyaRrDRtEq0IlDi0KydkS47-nj9yoUHybTfMNhrQtdCVibWrryiY3mBSq4L5KKpSv8Gt30hzjwNAGc7_trgWgYKPRsSEUkcQhUzJUZINhNeTHLfxhkOJ0/s1600/Img_2002A.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="254" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2NTn704niEoRObcrieeg1hTzyaRrDRtEq0IlDi0KydkS47-nj9yoUHybTfMNhrQtdCVibWrryiY3mBSq4L5KKpSv8Gt30hzjwNAGc7_trgWgYKPRsSEUkcQhUzJUZINhNeTHLfxhkOJ0/s640/Img_2002A.jpg" width="640" /></a></div>I had previously made the sand cores from a mix of silica sand and sodium silicate which was hardened with CO2 (You can find out about that step on the <a href="http://railwaybobrestorations.blogspot.com/2010/08/morning-at-alumaloy-castings-1990.html">end of this link</a>.) The sand cores were then carefully inserted into the mold. Because of adjustments I had made when "fine-tuning" the pattern, the sand cores had to be sanded so that they had a better fit when inserted into their cavities. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXpC57W8_7oPWuBDLMNPvjAij-HzC8b-Nc-V9r7NehZiODoeBqDQSLVuD5PoI546z8PWegFFWEGjZrzDOO8Ws7N1m2ACLY-8_w8_EUNQmA8HlyXYGcHU-NoVM6pKDYnIQ4V4X0Gk004Ps/s1600/Img_2005.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXpC57W8_7oPWuBDLMNPvjAij-HzC8b-Nc-V9r7NehZiODoeBqDQSLVuD5PoI546z8PWegFFWEGjZrzDOO8Ws7N1m2ACLY-8_w8_EUNQmA8HlyXYGcHU-NoVM6pKDYnIQ4V4X0Gk004Ps/s640/Img_2005.jpg" width="480" /></a></div>With the sand cores adjusted and fitted into their cavities, it was time to fit the cope back onto the drag. Here's what the drag part of the mold looked like before the cope was placed back on. It's at this stage of the molding process that you can visualize the purpose of the yellow blocks of wood attached to the sides of the patterns. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcEnPT4IMlhq0a0X_A-kM2KwLd9pqeEVrBR72PYCWek1mhmo8qzt-qWf1H9mtatJVYCCdEhZjXdMhsdLMKNalzgkA5CgffaRsq13Mc9apRZRzSTKLm7FvLZ4zBAcl5CiE-aGk6e99WlLk/s1600/Img_2009.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcEnPT4IMlhq0a0X_A-kM2KwLd9pqeEVrBR72PYCWek1mhmo8qzt-qWf1H9mtatJVYCCdEhZjXdMhsdLMKNalzgkA5CgffaRsq13Mc9apRZRzSTKLm7FvLZ4zBAcl5CiE-aGk6e99WlLk/s640/Img_2009.jpg" width="640" /></a></div>Marco and one of the workers then carefully fitted the cope over the alignment pins in the drag (refer to the two pins sticking up on each side in the above photo) and down onto the drag. When the cope was in place, it was then raised about 6" and the drag examined to ensure that the top parts of the sand cores hadn't knocked loose any sand.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgOjZclYCEomBFqivd9EajNH740lZoWG_-bprCiIP2AVsDAVIrlrZGolKWyM4WKpwSBq2qaBgM1bXVORgsAsY2yb-DErj8DOU90uOfadbCBPnxUCcOh_t_y18snmsBkTenicf18zi1wxM/s1600/Img_2011.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgOjZclYCEomBFqivd9EajNH740lZoWG_-bprCiIP2AVsDAVIrlrZGolKWyM4WKpwSBq2qaBgM1bXVORgsAsY2yb-DErj8DOU90uOfadbCBPnxUCcOh_t_y18snmsBkTenicf18zi1wxM/s640/Img_2011.jpg" width="480" /></a></div>And here's our green sand mold ready to be charged with molten aluminum. The flask has been weighted down with some small aluminum ingots so that the cope doesn't lift off the drag and spoil the casting.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXxOGKN0HN5U04s-wLSNhCSQCDIzt19HWtDxrLZoZb6DdGEC8a9m8ARyFlQwHHZM42Axj4bCzKMT3Du2qscp5jaNAZPr7XYpUdkW8xwl_yiUspjxEm-TUpJDQhDjUxKXLwwgo9YL_YQGU/s1600/Img_2015.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXxOGKN0HN5U04s-wLSNhCSQCDIzt19HWtDxrLZoZb6DdGEC8a9m8ARyFlQwHHZM42Axj4bCzKMT3Du2qscp5jaNAZPr7XYpUdkW8xwl_yiUspjxEm-TUpJDQhDjUxKXLwwgo9YL_YQGU/s640/Img_2015.jpg" width="480" /></a></div> While Marco was preparing the mold, one of the workers was charging the foundry with aluminum ingots and scrap that had been cut off from other castings. Pure aluminum hardly ever exists on its own. It is usually alloyed with other non-ferrous metals. Because there are different alloys of aluminum, the scrap had been thrown into different barrels to be remelted with their specific alloy. In addition to castings that haven't met muster, most of the scrap comes from the sprues and gates that have been cut from their castings.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhJyDRHHT_Pbpkfz4jadUFNEiQXUEA5tYiJKOX-jVkRZDw34RXmNbPhExjG9dKy3qt3NeMZpHMsZKqR96U54tagmgayntV-OZJCPekGpzW6q2RIaQUxjUILvDhL2trsPc_1PeBiB4XiLwU/s1600/Img_2014A.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="364" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhJyDRHHT_Pbpkfz4jadUFNEiQXUEA5tYiJKOX-jVkRZDw34RXmNbPhExjG9dKy3qt3NeMZpHMsZKqR96U54tagmgayntV-OZJCPekGpzW6q2RIaQUxjUILvDhL2trsPc_1PeBiB4XiLwU/s640/Img_2014A.jpg" width="640" /></a></div>With the molten aluminum now reaching 1,380 degrees Fahrenheit, the aluminum was ready for pouring. Flux was added to the foundry to bring the dross up to the top and to de-gas the aluminum. The ladle was scooped into the molten metal and carried over to the mold. The liquid aluminum was slowly poured into the sprue hole until it rose completely in the riser.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEirqDPzgfZ-f_mTDHVRc2gq7t_qQ2KWfqVtbKH2_9VSAvIuRVVSFCgqM76LfiZURd5JHiDhgupgHUhNvFVMilRm4nowjMRSTixG1J0vrEiBGOJQukGY7xVKYKzhF3hvGRna1H7I1yqrldw/s1600/Img_2018A.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="282" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEirqDPzgfZ-f_mTDHVRc2gq7t_qQ2KWfqVtbKH2_9VSAvIuRVVSFCgqM76LfiZURd5JHiDhgupgHUhNvFVMilRm4nowjMRSTixG1J0vrEiBGOJQukGY7xVKYKzhF3hvGRna1H7I1yqrldw/s640/Img_2018A.jpg" width="640" /></a></div>As the molten metal began to cool, the aluminum in the riser began to shrink until it was almost 1" below the level when it had first been poured. It was hard to believe that the metal had shrunk that much in the cooling process. It was very easy to visualize the shrinkage that would have occurred within the pattern if risers hadn't been added to the mold. (I've added red lines to indicate the amount of shrinkage.) <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiCoNV82xnyV8P2unyVFqJ9aINwah-pU0vHedl2yf2GkvR3YAYTXsNyfQAbMyrlX2Rk8IiJqRrsUNsYcFqiM4ypiXNdTPTJlWtb7t3FR1G0AY00l_eX8DHDpgLl_T6EhQfRMBBIMqqlm6Q/s1600/Img_2023.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiCoNV82xnyV8P2unyVFqJ9aINwah-pU0vHedl2yf2GkvR3YAYTXsNyfQAbMyrlX2Rk8IiJqRrsUNsYcFqiM4ypiXNdTPTJlWtb7t3FR1G0AY00l_eX8DHDpgLl_T6EhQfRMBBIMqqlm6Q/s640/Img_2023.jpg" width="480" /></a></div>Extra molten aluminum was poured into the top of the riser. The "weight" of the molten aluminum in the riser provides pressure to the molten aluminum inside the pattern. Any shrinkage of aluminum inside the pattern is replaced by the pressure of molten aluminum in the riser.<br />
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The mold and casting were left for 45 minutes until the aluminum had solidified. The sand mold was then dumped into the "recycle" hopper. The hot steam from the damp sand rose up as the perfect casting (complete with sprues and risers) appeared on the scene for the first time.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcNMJHS-BByT8OR0CB4e_MdhF4uqud-xbTLbXWZydl1P_D-sh_C6RINmaMhLrYNSMz3b_w27zKWZSmfJ_Z-zaKl6KZPWLRDY87oAWq-bJjWvVKtHDHBtsRvE_ax1tlodtUz0F_XgjoJfs/s1600/Img_2028A.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcNMJHS-BByT8OR0CB4e_MdhF4uqud-xbTLbXWZydl1P_D-sh_C6RINmaMhLrYNSMz3b_w27zKWZSmfJ_Z-zaKl6KZPWLRDY87oAWq-bJjWvVKtHDHBtsRvE_ax1tlodtUz0F_XgjoJfs/s640/Img_2028A.jpg" width="640" /></a></div>The casting was placed outside in the cold for an hour to quickly cool off (I had to return back to Ottawa that day). Once cooled, the sand cores were vibrated from the casting by an air-impact hammer vibrating the aluminum riser. With the sand cores removed, you could clearly see the outline of the two castings.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh1mXydae58l2yUQBCFZeIYqZm-8LKhIng26tm6j7agTPiIrcAV5Itfn1PdYELH32MIpZm6PAorQtJ1A91KkThEYjV5t-FgahBgk5xnSUDWBQr5Y26IzM94EjYi-yrX8Ff-cx819etNYl8/s1600/Img_2032.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="598" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh1mXydae58l2yUQBCFZeIYqZm-8LKhIng26tm6j7agTPiIrcAV5Itfn1PdYELH32MIpZm6PAorQtJ1A91KkThEYjV5t-FgahBgk5xnSUDWBQr5Y26IzM94EjYi-yrX8Ff-cx819etNYl8/s640/Img_2032.jpg" width="640" /></a></div>It was next over to the metal band saw to cut off the sprue, gate and riser. This saw sliced through the aluminum like a knife through butter.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjM5HKHQZWzHeoxdtDVhqob3kErfI5lpiBCQ9ro3Oy8lEoyl24F5dSIlEW2KIOFi3cGiOh_XSNx8kU38Vo-hSDf2NzNF7Dq8GFYAT_LXFddOD8sD0uFEgUXHJOg7qZfB2SFNx1ne2NztF8/s1600/IMG_2034.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjM5HKHQZWzHeoxdtDVhqob3kErfI5lpiBCQ9ro3Oy8lEoyl24F5dSIlEW2KIOFi3cGiOh_XSNx8kU38Vo-hSDf2NzNF7Dq8GFYAT_LXFddOD8sD0uFEgUXHJOg7qZfB2SFNx1ne2NztF8/s640/IMG_2034.JPG" width="640" /></a></div>The castings were then cleaned up on the belt sanders and angle grinders until all of the "flash" had been cut from the castings.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh6BSQWtb1NqQ-feVLcnbTJqMKpqwoqXHSYSfve4sZlvCqeezQfV5EWdXFSzGIuYe6xpjIW0VTyDHliIb0z_oLjKMUla8yek4lnQnN8tqkQkQchcske5eTzt0gvzK9olb9EbaUqx_a23mI/s1600/Img_2036.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh6BSQWtb1NqQ-feVLcnbTJqMKpqwoqXHSYSfve4sZlvCqeezQfV5EWdXFSzGIuYe6xpjIW0VTyDHliIb0z_oLjKMUla8yek4lnQnN8tqkQkQchcske5eTzt0gvzK9olb9EbaUqx_a23mI/s640/Img_2036.jpg" width="480" /></a></div>And here's what the castings finally look like.<br />
The Top View:<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi-eIQ9NcZqlaEbZgsIfzmK8r1y-BoTbTauz9da5kPZ_VcJo6JEaJlNXywyVyhlEATBq3vUa8IKYgngpTaTZrHHp6pYfLgPlp0tBu8wFUMgESZ43t7qcrwtLyCHIZ-6lxBZdUW0AUSDc8w/s1600/Img_2039.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="584" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi-eIQ9NcZqlaEbZgsIfzmK8r1y-BoTbTauz9da5kPZ_VcJo6JEaJlNXywyVyhlEATBq3vUa8IKYgngpTaTZrHHp6pYfLgPlp0tBu8wFUMgESZ43t7qcrwtLyCHIZ-6lxBZdUW0AUSDc8w/s640/Img_2039.jpg" width="640" /></a></div>End Views:<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEga_wC6DsZ9KMiifgJbaOqlupe47Ie31DK6lLDu18uuskG0S1r6n_I80fYzjm8tmijC8Vw_JQ4Pu0PEZ2hJ_J25mqg0TYROVo97nUnEbNSVgVLg2FtBD70jG3CokqsuVUbAiECfnvebm1o/s1600/Img_2045A.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="638" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEga_wC6DsZ9KMiifgJbaOqlupe47Ie31DK6lLDu18uuskG0S1r6n_I80fYzjm8tmijC8Vw_JQ4Pu0PEZ2hJ_J25mqg0TYROVo97nUnEbNSVgVLg2FtBD70jG3CokqsuVUbAiECfnvebm1o/s640/Img_2045A.jpg" width="640" /></a></div>And here's a view of the original casting that I started out with when making the two patterns:<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhhdyvvJ8W1mXddct5dzvk54_WCmAW0atsY8hppQyF67Crh5T3Y16K4ovhb4KKecFcGgvrA44XYCj_IyotPIYWEhSzzyi1ZvNkc54Fk6no3oUcM8YCdyyg9CS6qRWPW-Fuq4JmnXAoS17k/s1600/09+Composite+Top+and+Side-1.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="324" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhhdyvvJ8W1mXddct5dzvk54_WCmAW0atsY8hppQyF67Crh5T3Y16K4ovhb4KKecFcGgvrA44XYCj_IyotPIYWEhSzzyi1ZvNkc54Fk6no3oUcM8YCdyyg9CS6qRWPW-Fuq4JmnXAoS17k/s640/09+Composite+Top+and+Side-1.jpg" width="640" /></a></div>Not bad, eh!!??<br />
<br />
All in all, it's been a very interesting year getting involved in this project. Starting with learning how to make patterns, experimenting with sodium silicate and CO2 to make sand cores, visiting with Marco, Paul, and Susi at Alumaloy on several occasions to see how it's done professionally, to the final steps of actually making the castings - it's been a very good educational experience for me.<br />
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Now to continue from here with trying some back-yard metal casting. But first, we gotta finish the Mikey Burner and get our foundry built.Unknownnoreply@blogger.com3tag:blogger.com,1999:blog-2481033622229007011.post-24658375750471394372010-10-31T13:57:00.000-07:002010-11-13T13:11:54.857-08:00Passenger Car Window Covers (For passenger cars with sliding windows)<b>How often have you acquired a passenger car, complete with sliding windows with the glass all intact at the railway yard, only to discover a few days later that every glass pane in the car has been smashed by the vandals? Or, if you have a passenger car that you want to cover the windows so that they don't get smashed, the only way to fasten the plywood covers is with screws or nails through the side of that beautifully crafted window. </b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9XX_nC03F1Kt9UWJrqrSpMqBrIq9YjENYmaIpCI1dMgkEjfEXlWOevAyTVgYmv818it0OdfOjvkdES1eQmP1DaiTk_gf8gfzCAoLCTUIn8HlpcdcxFHyxqHbe4WSlMcvRKcpLolJkJv4/s1600/00+Passenger+Car.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9XX_nC03F1Kt9UWJrqrSpMqBrIq9YjENYmaIpCI1dMgkEjfEXlWOevAyTVgYmv818it0OdfOjvkdES1eQmP1DaiTk_gf8gfzCAoLCTUIn8HlpcdcxFHyxqHbe4WSlMcvRKcpLolJkJv4/s640/00+Passenger+Car.jpg" width="640" /></a></div><div class="separator" style="clear: both; text-align: center;"></div><b>First developed by Ross Robinson back in 1992 for his GTW caboose, here's a method that requires no screws or nails into windows, frames, or beautiful mahogany wood. If you know you are getting a passenger car ahead of time, you can fabricate the window covers in advance and install the window covers in the railway yard. </b><br />
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<b><u>Elements of The Window Cover</u></b> <br />
<b>For passenger cars with sliding windows, the window rests on a steel sill and slides up into a cavity inside the wall of the passenger car. Our window covers make use of these two facts - the steel sill and the cavity inside the wall. </b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjhtJH-u37WOK6tDvD3-awYVUOsO8Rx3LYy2McDy24FvYG94YOJF-Co9pyJdrbCCJrXr6jZCGfHgcZjEmYgiylBZY-_6n0U2uT8GzlvMtECA_lZa_7uDVzPHINANQZ3VA0fMM8jtbhIUUI/s1600/02+Elements+of+Window+Cover.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjhtJH-u37WOK6tDvD3-awYVUOsO8Rx3LYy2McDy24FvYG94YOJF-Co9pyJdrbCCJrXr6jZCGfHgcZjEmYgiylBZY-_6n0U2uT8GzlvMtECA_lZa_7uDVzPHINANQZ3VA0fMM8jtbhIUUI/s640/02+Elements+of+Window+Cover.jpg" width="438" /></a> </div> <b>The window cover consists of 3 pieces plus 8 carriage bolts and nyloc nuts:</b> <br />
<ul><li> <b>A 1/2" plywood panel that completely covers the opening of the window frame - typically 271/2"x 34"</b></li>
<li> <b>A fabricated piece of 22 gauge sheet metal fastened to the top of the plywood panel with four 1/4"x 3/4" carriage bolts and nyloc nuts</b></li>
<li> <b>A fabricated piece of 22 gauge sheet metal that resembles a piece of eavestrough fastened to the bottom of the plywood panel with four 1/4"x 3/4" carriage bolts and nyloc nuts. </b><b> </b><b> </b><b> </b></li>
</ul><b>For installation, with one person working on the outside and another working on the inside of the passenger car, window covers can be installed or removed in less than an hour. </b> <b>Installed from the outside of the car, first, the person inside opens the window to about 9". Second, the person outside inserts the top piece of sheet metal into the top of the window frame. Third, they then push the bottom piece of sheet metal into the bottom of the steel window sill. Fourth, the person inside lowers the window onto the bottom piece of sheet metal. The window holds the window cover securely in place. </b><br />
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<b><u>Fabricating The Plywood Panels</u></b><br />
<b>By setting up an "assembly line", window covers can be readily manufactured in short order. </b><b> </b><br />
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<b>The first step is to fabricate the plywood panels. The width of the panel is the complete width of the window opening. To this measurement, add 1" to account for the window track on each side of the window opening. For the height of the panel, measure window opening from the top of the steel panel to the bottom of the steel window sill. To this height, add 1" as the window cover will be about 3" away from the window. You should end up with measurements that approximate 271/2"x 34". </b><br />
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<b>The windows in the bathrooms at each end of the passenger car may be slightly narrower at about 251/2". </b> <br />
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<b>The best size of plywood is 1/2" as 1/4" plywood has no "structure" to it and will quickly warp, and 3/4" plywood results in a very heavy window cover. 1/2" poplar plywood that is used as sheathing or underlay on new houses is about the right density. </b> <br />
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<b>From a 4'x 8'x 1/2" sheet of plywood, you can get three 1-piece window covers (Panel A, Panel B, Panel, C) plus 3 pieces that you can assemble for one extra window cover (Panel D-1, Panel D-2, Panel D-3), and two pieces of scrap as shown in the cutting diagram below. </b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjRinHAuvyIl4Ckhp_HcPWdDQ-PvH-wqwpwkt275NvsMUYbg_UcVgjyB75QqHcL56_tT_87bSQUwnvqWdjFlayj5rKcTykieawZJL9eZMw8phWoKxZT2ytCKRR-0NUSh5bomjjfi_RWNcQ/s1600/01+Plywood+Cutting+Plan.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="442" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjRinHAuvyIl4Ckhp_HcPWdDQ-PvH-wqwpwkt275NvsMUYbg_UcVgjyB75QqHcL56_tT_87bSQUwnvqWdjFlayj5rKcTykieawZJL9eZMw8phWoKxZT2ytCKRR-0NUSh5bomjjfi_RWNcQ/s640/01+Plywood+Cutting+Plan.jpg" width="640" /></a></div><b>These 3 extra pieces (Panel D-1, Panel D-2, Panel D-3) will have to be joined together to produce the 4th panel. An air-powered brad-nailer will quickly do the trick. </b> <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiGWkXRQ7kM8V8mSrXIRsu589BHzCzPUGVaIfcCDtJf0aFXDyje4i70IA7a4s8HlIyr_87dYT3eNDEdZKTKiDhTrQtIiyzNR24eIhDzlkciEISFF5jk1lNXAGzmN8u1-pLcIQCZRUP5xow/s1600/01+Plywood+Pieces+Joined.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiGWkXRQ7kM8V8mSrXIRsu589BHzCzPUGVaIfcCDtJf0aFXDyje4i70IA7a4s8HlIyr_87dYT3eNDEdZKTKiDhTrQtIiyzNR24eIhDzlkciEISFF5jk1lNXAGzmN8u1-pLcIQCZRUP5xow/s640/01+Plywood+Pieces+Joined.jpg" width="526" /></a></div><b>On a passenger car with 44 windows, 11 sheets of plywood will produce 44 window covers. </b><br />
<b>You may be tempted to try and truck 11 sheets of 1/2" plywood away from your local lumber centre on the top of the car, in the back of the pickup truck, or minivan. </b><br />
<b> </b> <br />
<b>Please don't. Lumber centres like Home Depot, Rona, Home Hardware, etc have specialized saw service departments. Wheel the sheets of plywood over to the saw service and have them cut up the plywood for you. This will save you lots of time. </b><br />
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<b>It can be quite a job trying to get 11 sheets of plywood cut, painted, sheet metal pieces installed all at once. Break up the job so that you purchase and cut 3 - 5 sheets of plywood at a time. Once you have completed the window covers for these 3 - 5 sheets of plywood, return to your local lumber centre and purchase another 3 - 5 sheets of plywood. </b><br />
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<b>The cost of a 1/2" sheet of exterior sheathing plywood will cost about $20 - $25 per sheet - about $5 - $6 per window cover. If you aren't in a rush to finish your window covers, lurk around the cull bin of your building material store. Or, take a look at that stack of plywood to see if there are any sheets that have been damaged by the forklift or the metal straps. Over a period of weeks, you may be able to find small sheets of plywood culls, or plywood with the corners smashed. If you are sharp with your negotiations, you may be able to pick up damaged sheets for $10 or half sheets of culls for about $5. This can reduce the cost of plywood to about $2 per window cover. </b><br />
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<b><u>Painting The Plywood Panels</u></b> <br />
<b>With the rain, snow, and sun, unpainted plywood will deteriorate, de-laminate, and look ugly in very short order. Two coats of exterior gloss alkyd or urethane rust paint will protect the plywood panels and make your passenger car look better than what it currently is. Paint the plywood panels the same colour as your passenger car so that the window cover becomes an integral part of the car. </b><br />
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<b>Painting the plywood panels is the type of work that can be done in your basement workshop at home over several evenings. It doesn't require special equipment or space. </b><br />
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<b>Don't paint the plywood window covers white with black outlines of passengers sitting inside the car. Plywood panels painted white or any other light colour is an invitation for vandals to have a go at the car. </b><br />
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<b>We used Home Hardware rust paint because it is a high gloss exterior urethane paint that can be tinted into our favourite railway colour. We applied the paint with a 4" roller. Make sure the plies of the plywood are well sealed with paint. Paint one side of each panel and let it dry. Turn the panel over and paint the other side. Repeat this process until two coats of paint have been applied to each panel. Make sure you paint the edges so that the plies of the plywood are well sealed. </b><b> </b><b> </b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhvo7RYsknECCEF1OkRnNIT0w6HYOj15tWoMDU2sD2rEErnka3aqmK0ix3fXqHeGnPnP48mJoPZy1BWmdkp-NXHvjUscIFjNR-F4nFF2Fmfp2lfL8aQnUGzKYl3C7xMZ7mAiixBh9GRPy8/s1600/20+Plywood+Half+Painted.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhvo7RYsknECCEF1OkRnNIT0w6HYOj15tWoMDU2sD2rEErnka3aqmK0ix3fXqHeGnPnP48mJoPZy1BWmdkp-NXHvjUscIFjNR-F4nFF2Fmfp2lfL8aQnUGzKYl3C7xMZ7mAiixBh9GRPy8/s640/20+Plywood+Half+Painted.jpg" width="640" /></a></div><b></b><br />
<b>In some cases, the middle plies along the edges of the plywood may be hollow, creating a space between the plies that is weak. Mix up some auto body filler and stuff the body filler into this space. Sand and apply paint. Do this kind of work outside as it smells up the place and gets very dusty when sanding. An angle grinder with a "flap-disk" will do the sanding real quick.</b><br />
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<b>Painting the plywood panels is a job that can be done in the basement - either at your museum or at home. When painting a large number of panels at once, you will quickly run out of space to hang the wet panels. Before you start painting the panels, drill two 1/8" or slightly larger holes in each corner about 1" in from the top edges. Hang the plywood panels on a "wire chain" from the joists in the basement. </b><br />
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<b><u>Making "Chain Hangers"</u></b><br />
<b>I purchased several pieces of "wire chain" - each length about 24" long. I cut the link at each end as shown below and then unravelled and bent the link at each end so that I had a 90 degree hook at each end. These hooks fit into the 1/8" holes drilled into the top edges of the plywood panel. As I finish painting one side of the panel, I slip the hooks into the holes and hang the panel from nails I hammered into the floor joists in the basement. The chains and holes can also be used to store the window covers when they need to be removed from the passenger car windows for the season. </b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiA0RcMlKOIL3rlRWwaERLEkgHhJ-2uY4alA18JSoux9QGq9vFdmPOyZ4YKpzGO5WKwSSXKn5AAN6JdLmlE4KTvL95iL3oPdbCA51xWXD1BGM9dyvYoOeh9GIyoMaC5QUTQR7uu_x83vB8/s1600/15+Making+Hanging+Chains.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="438" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiA0RcMlKOIL3rlRWwaERLEkgHhJ-2uY4alA18JSoux9QGq9vFdmPOyZ4YKpzGO5WKwSSXKn5AAN6JdLmlE4KTvL95iL3oPdbCA51xWXD1BGM9dyvYoOeh9GIyoMaC5QUTQR7uu_x83vB8/s640/15+Making+Hanging+Chains.jpg" width="640" /></a></div><b>Here's one panel that I've just finished painting with the hooks inserted, ready for hanging to dry. </b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh07pBjAWbQEqqq3afpDUx2b-CICXrFeMxPdpOptzT0VYiNQLstYP8oylLYu0kjDRYdHK6ktU54KHHy9u8MbSxQ62fjBXgUJ9oiuXuBEZrjN3lAyTwXjYoQKL8csX4mOUFbksuv4Zaxhno/s1600/60+Window+Covers+-+Painting+Plywood.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh07pBjAWbQEqqq3afpDUx2b-CICXrFeMxPdpOptzT0VYiNQLstYP8oylLYu0kjDRYdHK6ktU54KHHy9u8MbSxQ62fjBXgUJ9oiuXuBEZrjN3lAyTwXjYoQKL8csX4mOUFbksuv4Zaxhno/s640/60+Window+Covers+-+Painting+Plywood.jpg" width="640" /></a></div><b>For those of you who are Canadian National Railways fans, here's the colour formula for CN #11 Green at Home Hardware - in the gallon size and in the quart size. </b><br />
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<b><u>CNR #11 Green</u></b> <br />
<b>Home Hardware (Beauti-Tone) Exterior/Alkyd/ Rust Coat</b><b> </b><br />
<u><b>Gallon Formula:</b></u> <br />
<b>Base # 64-03 Clear Base, 1 gallon size</b> <br />
<b>Colourant B: 4 ounces + 26 shots</b> <br />
<b>Colourant C: 4 ounces + 14 shots</b> <br />
<b>Colourant G: 16 shots</b> <br />
<b>Colourant Z: 8 shots</b><br />
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<u><b>Quart Formula:</b></u> <br />
<b>Base # 64-03 Clear Base, 1 quart size</b> <br />
<b>Colourant B: 1 ounce + 6 shots + 1 half shot</b> <br />
<b>Colourant C: 1 ounce + 3 shots + 1 half shot</b> <br />
<b>Colourant G: 4 shots</b> <br />
<b>Colourant Z: 2 shots</b><b> </b><br />
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<b><u>Fabricating The Sheet Metal Pieces</u></b> <br />
<span style="font-weight: bold;">T</span><b>here are two ways to fabricate the sheet metal pieces. </b><b>Purchase some 22 gauge sheet metal and fabricate the pieces yourself. OR </b><b>Take these diagrams to a sheet metal shop and ask them to fabricate the sheet metal pieces. I chose to visit the sheet metal shop. To save some money, I drilled the holes and snipped the corners, saving about $2 per window. My cost on sheet metal for 44 windows on one passenger car was $250 for one 44-window passenger car - about </b><b>$6 a pair. </b><br />
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<b>If you fabricate the pieces, you will have to purchase the sheet metal, cut it into strips, drill and bend the sheet metal on a sheet metal brake. This will take time, experience, and expertise. Which route you take will depend on the money available to you (this will be a good fund-raising project!), the expertise in your organization, the workshop and tools available to you. </b><br />
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<b>Here are the diagrams for fabricating the pieces of sheet metal.</b><br />
<b><u>Top Sheet Metal Piece</u></b> <br />
<b>The top piece is a piece of sheet metal 24" wide by 4" long with a 3/16" bend in the middle. The top corners of the sheet metal piece are clipped so that the edges are flat (pound the corners with a hammer after clipping the corners with your tin snips). </b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiB8jQ9HQlCl99a8aFoQtShbnxo-PqgXBJ5RQTkbmcpVFvjMPvssCp74rIh0EbO-DHjQJ6c0MdMNvUQErBbD4icOitpM4PigjdlYmJXAwMlVd4qenIxalXZubSes2ZvoehKf90VF_WHLvw/s1600/20+Sheet+Metal+-+Top+Piece.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="302" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiB8jQ9HQlCl99a8aFoQtShbnxo-PqgXBJ5RQTkbmcpVFvjMPvssCp74rIh0EbO-DHjQJ6c0MdMNvUQErBbD4icOitpM4PigjdlYmJXAwMlVd4qenIxalXZubSes2ZvoehKf90VF_WHLvw/s640/20+Sheet+Metal+-+Top+Piece.jpg" width="640" /></a> </div><br />
<b>And here's what the top piece looks like with the holes drilled and the top corners clipped.</b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjaW1Oh-N7u-W3w6yy4piLEq6W4VO20zMvCr5hNZBqqDb-_QvWRN-zfaLZU1pSTgasK1LCUeJTsBA8s89_d82b1OjKdPGpw5bZN7AUuxLi99w7vNfnrVD_nJ85qYpD7QUOmoFYfwNauydE/s1600/22+Top+Sheet+Metal+Piece.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="218" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjaW1Oh-N7u-W3w6yy4piLEq6W4VO20zMvCr5hNZBqqDb-_QvWRN-zfaLZU1pSTgasK1LCUeJTsBA8s89_d82b1OjKdPGpw5bZN7AUuxLi99w7vNfnrVD_nJ85qYpD7QUOmoFYfwNauydE/s640/22+Top+Sheet+Metal+Piece.jpg" width="640" /></a></div><br />
<b><u>Bottom Sheet Metal Piece</u></b> <br />
<b>If you decide to fabricate the sheet metal pieces yourself, the bottom piece requires a bit more thought and work. First drill the holes before you start bending the sheet metal. It will save you time and effort. </b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg1hQjAdmGpvGh-iMx2Fq2_3CffTscGaMhyphenhyphenB46TRkfxQC2tmqG8rzeNjUOs6Ob3vwv6ArfVvNnACBNJIQ233qhw_ajfYi73zezFP-0YDu4vJIK76iitf7wpwmwCRPPu5X0TuqWXxWT2oQ/s1600/31A+Sheet+Metal+-+Bottom+Piece.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="384" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjg1hQjAdmGpvGh-iMx2Fq2_3CffTscGaMhyphenhyphenB46TRkfxQC2tmqG8rzeNjUOs6Ob3vwv6ArfVvNnACBNJIQ233qhw_ajfYi73zezFP-0YDu4vJIK76iitf7wpwmwCRPPu5X0TuqWXxWT2oQ/s640/31A+Sheet+Metal+-+Bottom+Piece.jpg" width="640" /></a></div><b>Here's a photo of the bottom piece. </b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkjfFFbxyij5qRFwFVkQ6y8-SgR-9PPFCnQ4Y0MiK0gLC98cJxbTJq-nXShh3FUjBPk76MaQ34i8FnR5Yx5gvUUUmdIxkY20YaOKgKRYW_pCanTl6saZlGfuJ3v-dS65-wVPxCPfpzKw8/s1600/32+Bottom+Sheet+Metal+Piece+-+End+View.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkjfFFbxyij5qRFwFVkQ6y8-SgR-9PPFCnQ4Y0MiK0gLC98cJxbTJq-nXShh3FUjBPk76MaQ34i8FnR5Yx5gvUUUmdIxkY20YaOKgKRYW_pCanTl6saZlGfuJ3v-dS65-wVPxCPfpzKw8/s640/32+Bottom+Sheet+Metal+Piece+-+End+View.jpg" width="620" /></a></div><b> For locating the drill holes, here's a graphic of the 2" side of the bottom piece. </b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgtikaVg9wpeoJmgbaEZKHHmOwwBIErXs9tE9r-x_EBTL6qHs3ZwgOpH-M1GmLVLGoGMOm3elJP_6LXi2MMnyJzqVAWvhHwm-SNF9JiI5XCZMVtDSusj8GPmNwcl_wr2odGLGRDug_feHg/s1600/30+Sheet+Metal+-+Bottom+Piece.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="260" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgtikaVg9wpeoJmgbaEZKHHmOwwBIErXs9tE9r-x_EBTL6qHs3ZwgOpH-M1GmLVLGoGMOm3elJP_6LXi2MMnyJzqVAWvhHwm-SNF9JiI5XCZMVtDSusj8GPmNwcl_wr2odGLGRDug_feHg/s640/30+Sheet+Metal+-+Bottom+Piece.jpg" width="640" /></a></div><b>And here's a photo of the back of the bottom piece with the holes drilled. </b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhUU_LxcIMePBO9pONhCkNyvzyPu8kq_8UTcqSmPMuAdXvonqD2kB3nt9G0u4-JxRgkSqL7V5UGWxzZDlu8hE31_fJb6J_CEXTrDW-Z0zqzCi-BMZhy9HGna5NytNA-4NgK8nrqXPfPPZo/s1600/33+Bottom+Sheet+Metal+Piece+-+Back+View.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="156" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhUU_LxcIMePBO9pONhCkNyvzyPu8kq_8UTcqSmPMuAdXvonqD2kB3nt9G0u4-JxRgkSqL7V5UGWxzZDlu8hE31_fJb6J_CEXTrDW-Z0zqzCi-BMZhy9HGna5NytNA-4NgK8nrqXPfPPZo/s640/33+Bottom+Sheet+Metal+Piece+-+Back+View.jpg" width="640" /></a></div><b><u>Drilling The Holes In The Sheet Metal - Some Hints</u><u> </u></b><br />
<b>If you have the sheet metal shop fabricate the pieces for you, you can still save money if you drill the holes yourself. At $0.50 per hole, you will save about $4.00 per set.</b><br />
<b> </b><b> </b><br />
<b>Mark off the holes at the distances shown in the above diagrams. Centre punch the location of each hole. Drill the holes out with a 9/64" drill bit. We drilled the holes a bit oversized to allow a margin of error in drilling the holes in the plywood. </b><br />
<br />
<b>In drilling the bottom sheet metal piece, fabricate a piece of wood with the same cross-sectional shape as the sheet metal. Insert this into the "eavestrough" before you centre-punch and drill the holes. </b><br />
<br />
<b><u>Caution</u> - When drilling holes in sheet metal, make sure the sheet metal is securely fastened to your drill table. The sheet metal piece may spin and cause injuries when the drill breaks through the underside of the sheet metal. </b><br />
<br />
<b>Most of the fabricating work, drilling holes, bending corners, etc can be done on an "assembly line" basis in a couple of evenings. Because the sheet metal shop fabricated my pieces, my work was limited to snipping off the corners and drilling the 8 holes. </b><br />
<br />
<span style="font-size: small;"><b><u>Installing The Top Sheet Metal Piece To The Plywood Panel</u></b> </span><br />
<b>Plywood has a tendency to curl. You will want to take advantage of this curl when installing the sheet metal pieces. The sheet metal pieces are installed as shown in the diagram below - on top of the curl. When you install the window cover, you will force the curve to "unfurl", making a nice tension-tight fit. </b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgBzFg3u-pvl5WFwl12JcdktfAR2VBinIGSSBjpNDDiJR9kdZFwvY3jWSoY0hoQD3VWLHagutypLMqKbzMXjDJWYU4Kfvj9_hZJXGQxHzLnBMsFsbOHuwdbRc4axBpa6IFc7G4f19qYGxc/s1600/52+Bent+Window+Cover.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="248" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgBzFg3u-pvl5WFwl12JcdktfAR2VBinIGSSBjpNDDiJR9kdZFwvY3jWSoY0hoQD3VWLHagutypLMqKbzMXjDJWYU4Kfvj9_hZJXGQxHzLnBMsFsbOHuwdbRc4axBpa6IFc7G4f19qYGxc/s640/52+Bent+Window+Cover.jpg" width="640" /></a></div><div class="separator" style="clear: both; text-align: center;"></div><b> </b><b> You will need the following tools/ supplies to install the sheet metal pieces to the plywood:</b> <br />
<ul><li> <b>Straight Edge</b></li>
<li> <b>Ruler</b></li>
<li><b>"Fine" tip permanent marker (for marking on the sheet metal pieces)</b></li>
<li><b>Pencil</b></li>
<li> <b>Two pieces of scrap wood</b></li>
<li> <b>Two C-clamps</b></li>
<li><b>Two T-squares (optional) (for locating bottom sheet metal piece on plywood) </b></li>
<li> <b>1/4" drill bit (a Forstener bit will reduce spintering)</b></li>
<li> <b>Eight 1/4"x 3/4" carriage bolts for each panel</b></li>
<li> <b>Eight 1/4" nyloc nuts for each panel</b></li>
<li> <b>1/2" box wrench</b></li>
<li> <b>Hammer (for tapping the square collar of the carriage bolt into plywood)</b></li>
</ul><b> </b><br />
T<b>he top sheet metal piece is fastened to the plywood panel in two steps. First, the middle two carriage bolts are installed. Then the outer carriage bolts are installed. </b> <br />
<ul><li> <b>Place the top piece of sheet metal on the top of the plywood panel so that the sheet metal is centred with equal space of plywood on each side of the sheet metal. The bend in the sheet metal should be right on the top edge of the plywood panel</b></li>
<li> <b>Place the piece of scrap wood under the plywood, install and tighten a clamp so that the sheet metal piece is held in place on the plywood panel. Repeat the process at the other end. </b></li>
<li> <b>From the top of the sheet metal, drill the two middle holes in the plywood</b></li>
<li> <b>Insert the carriage bolt from the bottom</b></li>
<li> <b>Install and tighten the two nuts. You may have to tap the head of the bolt with the hammer to seat the square collar of the carriage bolt into the plywood. </b></li>
</ul>Insert photo of installing middle carriage bolts.<br />
<ul><li> <b>Remove the clamps and pieces of scrap wood from the ends</b></li>
<li> <b>From the top of the sheet metal, drill the two end holes in the plywood</b></li>
<li> <b>Insert the carriage bolt from the bottom</b></li>
<li> <b>Install and tighten the two nuts.</b></li>
</ul><b></b><span style="font-size: small;"><b><u>Installing The Bottom Sheet Metal Piece To The Plywood Panel</u></b></span><br />
<span style="font-weight: bold;">Installing the bottom sheet metal piece to the plywood panel is a bit trickier than installing the top piece. In addition to a space of about 3" from the window sash to the outer edges of the window frame, the steel window sill is stepped about 1<span style="font-size: x-small;">1/2</span>" from the bottom edge of the window. This means that the bottom of the plywood panel will be about 1½" lower than the bottom of the window sash that sits in the bottom sheet metal piece. We have to account for this 1½" drop from horizontal when installing the bottom sheet metal piece to the plywood. </span> <br />
<ul><li><b>Slide the rule of one of the T-squares out to about 6". Use this T-square to draw a line 6" from the bottom edge of the plywood. This marks where the top of the bottom sheet metal piece will be fastened to the plywood.</b><b> </b></li>
<li><b>The sheet metal pieces are 24" wide and the plywood panel is 27<span style="font-size: x-small;">1/2</span>" wide - a difference of 3<span style="font-size: x-small;">1/2</span>". Slide the rule of the other T-square out to 1<span style="font-size: x-small;">3/4</span>" (half of 3<span style="font-size: x-small;">1/2</span>"). This will mark off the edges on the plywood where the sheet metal pieces are to be installed - ie 1<span style="font-size: x-small;">3/4</span>" from each edge of the plywood cover. </b></li>
<li><b>Place the bottom sheet metal piece on top of the plywood, lining the piece with the three lines drawn on the plywood in the previous two steps. </b></li>
<li><b>Clamp the plywood and sheet metal together along the outer edges of the plywood. </b></li>
<li>(Insert photo)</li>
<li><b>Turn the plywood over and drill the middle two holes in the plywood. This can get a bit tricky as there's no way for drilling a pilot hole. It's matter of lining up the hole visually and mentally with a little bit of ESP! </b></li>
<li><b>Insert the carriage bolt, screw on the nyloc nut and tighten. </b><b>You may have to tap the head of the bolt with the hammer to seat the square collar of the carriage bolt into the plywood. </b></li>
<li><b> </b>(Insert photo.)<b> </b></li>
<li><b>Remove the clamps and drill the holes for the two outer holes. Install the carriage bolts and nyloc nuts. </b></li>
<li>(Insert photo.)<b> </b></li>
</ul><br />
<b>Voila! You have just fabricated a passenger car window cover. One done and only 43 more to go!</b><br />
<b> </b>(Insert photo.)<br />
<b><br />
</b><br />
<b><u>Paint The Exterior Of The Sheet Metal</u></b><br />
<b>If you install the completed window cover, you will see that the shininess of the sheet metal can "attract attention". In order to tone it down, paint the sheet metal with two coats of paint. This will also allow you to touch up any other spots on the window cover that may have been "tarnished" in the fabrication process (eg missed drill holes, etc). </b><br />
<br />
<b>Here's a couple of photos of a complete set of window covers - one side of the coach. </b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-6-VdMIv2RPpIlr83fQTchm1BiMIM0KMZYS5LhfRwC6zUGuuzvJmurt1uNBepPTq8yrjvrog9sCfBTH6OsHD7_YVoVf3YkAflHBW0WYkAsylu-W7sDecfAplKUD6SIJkIKewkTphD96Q/s1600/87+Installed+Window+Covers.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="202" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-6-VdMIv2RPpIlr83fQTchm1BiMIM0KMZYS5LhfRwC6zUGuuzvJmurt1uNBepPTq8yrjvrog9sCfBTH6OsHD7_YVoVf3YkAflHBW0WYkAsylu-W7sDecfAplKUD6SIJkIKewkTphD96Q/s640/87+Installed+Window+Covers.jpg" width="640" /></a></div><b>and a close-up of a couple of the covers. </b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj5IrjcQ1Fndp4XdMtYu141g-2EgWxgaDIqoIKMB1p1clkMs7zPHNiq5ea8Kw6h38i6ty1Jyk8-um4M5k6kCKdBNEA7Idy-2PZLq1DQYs7T1WA0V42QL_H2eEiImER2lBipI3yaba1Bppo/s1600/88+Installed+Window+Covers.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="428" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj5IrjcQ1Fndp4XdMtYu141g-2EgWxgaDIqoIKMB1p1clkMs7zPHNiq5ea8Kw6h38i6ty1Jyk8-um4M5k6kCKdBNEA7Idy-2PZLq1DQYs7T1WA0V42QL_H2eEiImER2lBipI3yaba1Bppo/s640/88+Installed+Window+Covers.jpg" width="640" /></a></div><b> </b><b>If you do undertake this project, we'd be interested in seeing the results. </b>Unknownnoreply@blogger.com2tag:blogger.com,1999:blog-2481033622229007011.post-63143159205812967992010-10-16T17:05:00.000-07:002010-10-28T14:18:12.574-07:00Cutting Steel With The Plasma Cutter - Like Cutting Through a Piece of Cheese!!<span style="font-size: small;">The sparks were flying this morning, fer shur, at Science & Tech!! Got to cut 1" thick steel with the plasma cutter. Love that machine!! Cuts thru steel like it was cutting thru cheese!! </span><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhvbU8ZqyEqHBk0A6ztL0Cj-A20Fx8oQVRpEpczLDHpaxK4BqZSjw8Ty8b0OwOkCnsGC-aOirdAWuH2l_-Bva6rh-ggywV-25Z_BG3jH7mVoAnpjDK16VcX2zhM3ncL5EXAqqAAyWAuWEA/s1600/Plasma+Cutting.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhvbU8ZqyEqHBk0A6ztL0Cj-A20Fx8oQVRpEpczLDHpaxK4BqZSjw8Ty8b0OwOkCnsGC-aOirdAWuH2l_-Bva6rh-ggywV-25Z_BG3jH7mVoAnpjDK16VcX2zhM3ncL5EXAqqAAyWAuWEA/s640/Plasma+Cutting.jpg" width="480" /></a><span style="font-size: small;"> </span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;">The plywood being held down with the C-clamps is the pattern for half a pair of "rail tongs" - instead of lifting salad, they'll be used to lift rails (as in railway track). Cut the pattern 5/8" smaller than the final shape. Hold the plasma cutter vertically against the pattern. Squeeze the button and run the cutter around the edge of the pattern. Sparks and liquid steel blow out on the underside. Voila - half a pair of rail tongs!!!</span></div><div class="separator" style="clear: both; text-align: left;"><br />
</div><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;">The job started several weeks ago when Ross R asked me to cut out some patterns in 3/4" plywood from full-size drawings. Using good old-fashioned carbon paper, I transferred the pattern onto the plywood and then cut out the full-size pattern on the band-saw. </span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;"><br />
</span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;"><b><u>Interior Cuts (Pattern Is Our Final Product) - Reduce Pattern Size By 5/8"</u></b></span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;">The head of the plasma cutter is 1" wide and will make a 1/4" wide cut in the steel. We therefore have to account for this in making our wooden pattern. We can have two different types of cutting situations. In the first situation, the final piece of cut steel will be underneath our wooden pattern. I call this an "interior cut" because the cut steel will be inside our pattern. </span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;"><br />
</span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;">On an "interior cut" where the steel is underneath our plywood, we have to reduce the size of the plywood pattern by 5/8". The plasma cutter will then be cutting the steel right along the edge of the final cut. The centre of the plasma cutter has to be 5/8" away from the edge of the pattern. </span></div><div class="separator" style="clear: both; text-align: left;"><br />
</div><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;">So, using my T-square and a pencil, I traced a 5/8" pattern around the edge of the full-size plywood pattern. Again, using the band saw, I reduced the full-size pattern to what you see in the photo below. </span></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgQzOrwwfwHZOAVsh2P5SaLN9w-DPM3urmUt8rcnf7s-aUBx9SyvsaLWC88PiVQP762b1FOE99p-JK54lrrdhRDxkgDBdY3UablPNkX0ZxHBaN5OwxAGqVv3Og28aG-IxuH4tUWg6eu1ks/s1600/Plasma+Cutting+-+Interior+Cut.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="552" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgQzOrwwfwHZOAVsh2P5SaLN9w-DPM3urmUt8rcnf7s-aUBx9SyvsaLWC88PiVQP762b1FOE99p-JK54lrrdhRDxkgDBdY3UablPNkX0ZxHBaN5OwxAGqVv3Og28aG-IxuH4tUWg6eu1ks/s640/Plasma+Cutting+-+Interior+Cut.jpg" width="640" /></a></div><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;"> Most of our cuts will be interior cuts where the cut steel will be underneath our wooden pattern. </span></div><div class="separator" style="clear: both; text-align: left;"><br />
</div><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;">The plasma cutter produces a very rough and ragged edge. If the edge needs to be ground smooth, the pattern will only be reduced by 9/16", rather than 5/8". This additional 1/16" will leave sufficient steel for a smooth grind. </span></div><div class="separator" style="clear: both; text-align: left;"><br />
</div><span style="font-size: small;"></span><br />
<div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;"><b><u>Exterior Cuts (Pattern Is NOT Our Final Product) - Reduce Pattern Size By 1/2"</u></b></span><span style="font-size: small;"> </span></div><span style="font-size: small;"></span><br />
<span style="font-size: small;"></span><br />
<div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;">In the second cutting situation, it may not be possible to have the cut steel underneath our pattern. For example, our pattern may be too small for the plasma cutter to easily go around the pattern. In this case, the pattern is outside the final cut steel and NOT on top of the final cut steel the pattern. <br />
</span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;"><b><u><br />
</u></b></span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;">On an "exterior cut"we have to reduce the pattern by 1/2". </span></div><div class="separator" style="clear: both; text-align: left;"><br />
</div><div class="separator" style="clear: both; text-align: left;"><b><u><span style="font-size: small;">Plasma Cutter Settings</span></u></b></div><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;">We've been looking at the business end of the plasma cutter. Let's take a look at the end that makes it all possible. Here's a "back view" of the plasma cutter. </span></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhytwSGlvLJHPvQn9eGEQtdT7tmoX0_5gY0a0f8wR_NMlJB0AjrwGi08BXFNfXL-_n165cUemj1T27QCfL5SH_-LALS3rGQxZ0cJoqtrhqA1jUe4LlixghOxWrdXzQ6WBjDNnCvC7WIN0k/s1600/IMG_1772.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhytwSGlvLJHPvQn9eGEQtdT7tmoX0_5gY0a0f8wR_NMlJB0AjrwGi08BXFNfXL-_n165cUemj1T27QCfL5SH_-LALS3rGQxZ0cJoqtrhqA1jUe4LlixghOxWrdXzQ6WBjDNnCvC7WIN0k/s640/IMG_1772.JPG" width="640" /></a></div><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;">A large extension cord is wound up on the left side. The extension cord is only used if the work is far away from a wall plug. The regular cord, the ground wire, and the cutter gun are wound up on the back of the plasma cutter as shown in the following order:</span></div><ol><li><span style="font-size: small;">the regular cord</span></li>
<li><span style="font-size: small;">the ground wire</span></li>
<li><span style="font-size: small;">the cutter gun</span></li>
</ol><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;"> Let's now take a look at the front end of the plasma cutter. This is where me make the adjustments (if any) to control our cut. </span></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhwehRoBZpl_bxJ9_oLeK8AMkNpTsyEDpj8ZpmkYVVGRP6KuaS9q96jwOhUdlTze1xdPocjSBH7bxOofobA_BgAzhfV5ybF3X9SRqDLsggSzgs6-qZWs4sl5kxcK5BPLYX-LR7GEmwjC0E/s1600/IMG_1771.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhwehRoBZpl_bxJ9_oLeK8AMkNpTsyEDpj8ZpmkYVVGRP6KuaS9q96jwOhUdlTze1xdPocjSBH7bxOofobA_BgAzhfV5ybF3X9SRqDLsggSzgs6-qZWs4sl5kxcK5BPLYX-LR7GEmwjC0E/s640/IMG_1771.JPG" width="640" /></a></div><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;">Let's take a closer look at the control panel. </span></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhVUAaDXyUwS95o2Jg4X_OCDvrq3yuDRnsD-2q9y5IlMXpY_ve1OJDbCQMFS0BT5x_KspfduY8y1lCo74dSoYHELdQIQIf5GT1svi_j0KlBfS6VV00IcRj9njhaOJoValinBP70Tpmcgfg/s1600/IMG_1771+-+Control+Panel.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="382" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhVUAaDXyUwS95o2Jg4X_OCDvrq3yuDRnsD-2q9y5IlMXpY_ve1OJDbCQMFS0BT5x_KspfduY8y1lCo74dSoYHELdQIQIf5GT1svi_j0KlBfS6VV00IcRj9njhaOJoValinBP70Tpmcgfg/s640/IMG_1771+-+Control+Panel.jpg" width="640" /></a></div><div class="separator" style="clear: both; text-align: left;">To set up the controls, and with the plasma cutter plugged into the proper wall plug:</div><div class="separator" style="clear: both; text-align: left;"><br />
</div><ol><li>Press the green "On" button</li>
<li>Wait until both "Ready" lights are lit ("Ready" and "DC Power")</li>
<li>Set the amps to 100%. (If you are cutting sheet metal, see instructions below)</li>
<li><span style="font-size: small;">Normally, we would be doing "stop-and-start" cutting as we move our position around the pattern and steel. Set the</span> "Continuous" switch to "Off"</li>
<li>Flick the "Air Pressure" switch to "Test" and make sure it shows 75 psi. If required, adjust the pressure to 75 psi. flick the "Air Pressure" switch back to "Run" </li>
</ol><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;">THERE IS NO NEED TO OPEN UP THE BOX!! YOU AREN'T QUALIFIED TO ENTER THE BOX!</span></div><div class="separator" style="clear: both; text-align: left;"><br />
</div><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;">To cut steel, </span></div><ol><li><span style="font-size: small;">Connect the ground wire clamp to the steel to be cut </span></li>
<li><span style="font-size: small;">Hold the plasma cutter gun on the steel but with the electrode off of the steel</span></li>
<li><span style="font-size: small;">Squeeze and hold the trigger button</span></li>
<li><span style="font-size: small;">Air will immediately come out under pressure</span></li>
<li><span style="font-size: small;">In one or two seconds, a blue arc will emerge from the gun. </span></li>
<li><span style="font-size: small;">Slowly move the gun into the steel and against the pattern. </span></li>
<li><span style="font-size: small;">Move the gun slowly, always making sure that the liquid steel is blowing down. </span></li>
<li><span style="font-size: small;">Always "drag" the gun towards you. Never away from you or sideways. This will result in smoother cuts. </span></li>
<li><span style="font-size: small;">Take your time!</span></li>
<li><span style="font-size: small;">Move your body placement so that you are always "dragging" the gun towards you. </span></li>
<li><span style="font-size: small;">Stop and start your cutting as required. </span></li>
<li><span style="font-size: small;">Release the trigger button before you lift the gun from the steel!!</span></li>
<li><span style="font-size: small;">ALWAYS WEAR AN AUTO-DARKENING WELDING HELMET!!</span></li>
</ol><div class="separator" style="clear: both; text-align: left;"><span style="font-size: small;">To be continued.</span></div><h6 class="uiStreamMessage" style="font-weight: normal;"><span style="font-size: small;"><br />
</span></h6>Unknownnoreply@blogger.com8tag:blogger.com,1999:blog-2481033622229007011.post-35586073001810891582010-09-06T17:58:00.000-07:002010-09-06T18:13:51.603-07:00Patterns Finished & Ready For CastingIn a previous blog we demonstrated the bits and pieces of wood that make up the speeder sweep castings. Once we have the bits and pieces all brad-nailed and glued together, we create fillets (curves) between the ribs and the deck using automotive car body putty. It's a simple matter of squeezing the putty out of the tube and wiping it on the wood, smoothing it out with our finger to create a nice curve. A rubber glove helps to keep the putty off of our fingers. Several coats of body putty, with light sandings in between coats, and soon have nice curved fillets. <br />
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The foundryman is not a pattern maker so he needs to know what part of the pattern is the final casting and what part is sand core. In order to help him out, we give the patterns several coats of black and yellow paint - black outlining the final casting and yellow outlining the sand cores. In this way, when he pulls the pattern out of the mold, he knows which sand core goes into which cavity. The yellow outline of the pattern corresponds to a specific sand core.<br />
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Here's the top view of our pattern.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEix4bvD-IQDdsjrm1J6kDLu_iAaLkB3Hjhb_o1nJZYRKnxDOwb7stbYbywVbUq98K_VEDzkK3-BaraObcpEOjF7lE0sjab4YomaoEvhNSUPMIqJOkdP8jsZCb06rn7AuYDzmjGmDQZQNbo/s1600/36+Pattern-02.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="416" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEix4bvD-IQDdsjrm1J6kDLu_iAaLkB3Hjhb_o1nJZYRKnxDOwb7stbYbywVbUq98K_VEDzkK3-BaraObcpEOjF7lE0sjab4YomaoEvhNSUPMIqJOkdP8jsZCb06rn7AuYDzmjGmDQZQNbo/s640/36+Pattern-02.JPG" width="640" /></a></div>A head-on view. In addition to seeing the profile of the two sand cores that we'll be using, you can readily see that our pattern is in two parts. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHwG1fjtdyTPIGofLFD80_AVpCsnHm9ONa0SvHgPpe4r9bSFz5JZpvX-PLTaB06cnk79QoPw_bSYYNPxAiPEXHlEsmG9UWTsQfj4YTbnBWrrda7xxBr7Z7BgcX9vz8oiq3fMJfCc4WV10/s1600/36+Pattern-03.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="428" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHwG1fjtdyTPIGofLFD80_AVpCsnHm9ONa0SvHgPpe4r9bSFz5JZpvX-PLTaB06cnk79QoPw_bSYYNPxAiPEXHlEsmG9UWTsQfj4YTbnBWrrda7xxBr7Z7BgcX9vz8oiq3fMJfCc4WV10/s640/36+Pattern-03.JPG" width="640" /></a></div>You can also see where our parting line will be between the drag and the cope of our flask. What may not be readily evident is a potential undercut on the left side of the photo. When we put the top half of the pattern onto the base, we'll have to get rid of that undercut by building the drag part of our sand mold up before we fit the cope onto the drag. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1Q7Vx-t5BJHSERv1wSHd98wPxbix09RuPVNXrZCdSkSTaJyma2nABczU5mD_-o5Q8lJk_pc16fe4iJcJ5Nul1OzG92NuZXjYnLkUPuMYyZCQtw_3YfnqR3u6DUF7Qe6opLNnbXnxKtGQ/s1600/36+Pattern-03c.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="428" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1Q7Vx-t5BJHSERv1wSHd98wPxbix09RuPVNXrZCdSkSTaJyma2nABczU5mD_-o5Q8lJk_pc16fe4iJcJ5Nul1OzG92NuZXjYnLkUPuMYyZCQtw_3YfnqR3u6DUF7Qe6opLNnbXnxKtGQ/s640/36+Pattern-03c.jpg" width="640" /></a></div>A side view. Again you can see the top half of the pattern and the bottom half when you look at the wing. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUl5rvbrHwzyNrR8d0WVOnUh3_QEzKaiYHclM4CmyQs9LTSVYdThrQLYbtLQ3623a2HOzFWYnkP-N_PAVqWU6Si9tgrDDuTSxJREEmt2IG00cZyYq-VPqRd1uxsjFue95vRhKNgrxD01w/s1600/36+Pattern-04.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="312" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUl5rvbrHwzyNrR8d0WVOnUh3_QEzKaiYHclM4CmyQs9LTSVYdThrQLYbtLQ3623a2HOzFWYnkP-N_PAVqWU6Si9tgrDDuTSxJREEmt2IG00cZyYq-VPqRd1uxsjFue95vRhKNgrxD01w/s640/36+Pattern-04.JPG" width="640" /></a></div>Another side view but with the pattern rotated 180 degrees. You can readily see that our pattern is in two parts. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg2UHM-AvLYpkmwRtZ3HI-mBCluDJOVzzwBwSWSw_d7OvCQCVz1MfSRVrX_jCoQGNZHacsDGRmAhYg8Ltc_jd8qNO1mJtQ0-bPaoe9ulLV5sz43ax6fMYw9FppfT-4FY6UZ_tteICeHpgE/s1600/36+Pattern-05.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="260" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg2UHM-AvLYpkmwRtZ3HI-mBCluDJOVzzwBwSWSw_d7OvCQCVz1MfSRVrX_jCoQGNZHacsDGRmAhYg8Ltc_jd8qNO1mJtQ0-bPaoe9ulLV5sz43ax6fMYw9FppfT-4FY6UZ_tteICeHpgE/s640/36+Pattern-05.JPG" width="640" /></a></div>And a bottom view with the top part of the wing detached from the base. This photo clearly shows the ribs of our casting. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjhOrCb3Om-5NiCQnjlDlIBcyVlqI5ZItTrkA3A8XVqn9wxCZonGCOah45SE_9zPspreNcEVfwyJLxVmhkRwh9gNizEgffnvp3iHLvoSJGOU9QZ9EyHe30LT-qfy-miuPyQ5eBYW4sEqew/s1600/36+Pattern-07.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjhOrCb3Om-5NiCQnjlDlIBcyVlqI5ZItTrkA3A8XVqn9wxCZonGCOah45SE_9zPspreNcEVfwyJLxVmhkRwh9gNizEgffnvp3iHLvoSJGOU9QZ9EyHe30LT-qfy-miuPyQ5eBYW4sEqew/s640/36+Pattern-07.JPG" width="536" /></a></div>Here's an end view with the two sand cores that will fit into the mold cavity created by the yellow parts of the pattern. Note how the outline of the sand cores corresponds to the yellow outline of the pattern.<br />
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Our next step is to make sure that we can make a mold that will accept the sand cores and be ready for the molten aluminum. In effect, this will be a trial run of our mold making to make sure that everything fits together (we hope!).Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2481033622229007011.post-42196286505151913182010-08-26T17:19:00.000-07:002011-02-13T05:05:09.549-08:00A Morning At Alumaloy Castings (1990) Limited - How To Make A "Negative" Casting<u><b>The Company</b></u> - Alumaloy Castings (1990) Limited, 424 Birchmound Rd, Toronto, ON, Canada, M1K 7M6<br />
<u><b>The Challenge</b></u> - Using a "patio stone" rock as a pattern, make a "negative" of the rock. Then use that "negative" pattern to make a mold to make an aluminum casting. The aluminum casting will then be used by the landscape customer to make concrete "patio stone" rocks.<br />
<u><b>The Craftsmen</b></u> - Marco and Paul, two of the principals of Alumaloy and their employees. <br />
<u><b>The Circumstances</b></u> - A landscape customer wants to make concrete "patio stone" rocks out of a slurry mix of concrete. They sculped the "patio stone" pattern out of the slurry mix. They now need to make a "negative" mold out of this "patio stone" in order to to produce dozens of stones that are similar in shape, size, and look. Using the "patio stone" master for their pattern, they tried making the negative out of plaster of Paris without success. The landscape customer has now come to Alumaloy for a solution. And I've been fortunate to have just arrived on the scene with a challenge of my own (a much smaller one) to offer Alumaloy - but that's another story for another day.<br />
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<u><b>Making The "Negative" Pattern</b></u><br />
In a previous blog, I've discussed using sodium silicate and silica sand to make sand cores. Alumaloy uses the stuff to make their one-of-a-kind sand cores all the time. There's always a barrel or two of the stuff mixed up and ready to use at a moment's notice.<br />
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Paul put the patio stone face down on a mold board inside the cope-half of a flask that had lots of draft on the sides. He then stuffed some mixed sand along the edges to get rid of the undercuts (there were a few on the back of the stone) and oversprayed the mixed sand with some brown lacquer. This would help him to identify where the edges of the stone were. He added some 1/8" steel rod as reinforcing steel and some hooks so that they could lift the negative pattern out of the green sand mold. He also drilled some holes into the sides of the flask to insert some steel rods to tap the patio stone when it came time to remove the stone from the sand mix.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiW-kG5Qhrc17_GMzy-E3CPHu7cszpJV7ByDkWLlu4BRWSI4K54-x4GQAx8bdUYD1Tbpwb8JDavO39joZYSaqZJwTSYL7JlO4lRz7u6HaP2lveqE8p9qXLoowRrLz-Vad6ZMV1XtCWqHSI/s1600/IMG_1664.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiW-kG5Qhrc17_GMzy-E3CPHu7cszpJV7ByDkWLlu4BRWSI4K54-x4GQAx8bdUYD1Tbpwb8JDavO39joZYSaqZJwTSYL7JlO4lRz7u6HaP2lveqE8p9qXLoowRrLz-Vad6ZMV1XtCWqHSI/s640/IMG_1664.JPG" width="640" /></a></div>He filled the flask with the sodium-silicate-and-sand mix, tamping the sand tightly around the patio stone. When the flask was full, he struck off the excess sand. Next, he made about a dozen holes in the sand using a 1/8" steel rod. These holes would be used to get carbon dioxide (CO<span style="font-size: x-small;">2</span>) into the sand mix. The CO<span style="font-size: x-small;">2</span> would create a chemical reaction with the sand mix to harden the sand into a solid block of sand.<br />
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I wouldn't have believed it if I hadn't seen it with my own eyes! Using an air hose attached to the cylinder of CO<span style="font-size: x-small;">2</span>, he gave each hole a two-second (it could have been a 4 or 5 second) shot of CO<span style="font-size: x-small;">2</span>. He repeated this again. In less than 5 minutes, he had a solid chunk of sand which had the exact pattern (ridges, indentations, grain, etc) of the face of the patio stone.<br />
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Problem was he now had a 150 lb block of sand that he had to turn over to remove the original patio stone pattern from the block of sand. Calling on Marco (who was always on hand offering advice and going for things to keep things moving along), they both managed to turn the flask and block over so that the patio stone was exposed. A bit of digging and jabbing here and there and the patio stone came out. They next sprayed the sand casting with lacquer to seal the block of sand. As seen in the photo below, they now had the "negative" pattern that they needed to make the green sand mold and an aluminum casting. You can clearly see the fine detail of the rock that has been impressed into the "negative" sand pattern. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhbLcuuw6cjCOahB1iiTGTP1gR73vgf5LvL0xydUeQkyljWKcaXDvbQA6qG3TpyzYKP9Wxej9S-ab-dYhyphenhyphenyoY7f2fUe5FFtwDBEoSJCeW4mnMGBmWvvh-hu8NkfkWCOayHI6kX1EE2xYFw/s1600/IMG_1635.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhbLcuuw6cjCOahB1iiTGTP1gR73vgf5LvL0xydUeQkyljWKcaXDvbQA6qG3TpyzYKP9Wxej9S-ab-dYhyphenhyphenyoY7f2fUe5FFtwDBEoSJCeW4mnMGBmWvvh-hu8NkfkWCOayHI6kX1EE2xYFw/s640/IMG_1635.JPG" width="640" /></a></div>Placing the negative pattern on a pallet truck, they wheeled the 150 lb pattern into the mold-making part of the shop, lifted the heavy pattern face-up onto a mold board and then placed the drag-half of a large 30"x 36" flask over the pattern. This provided just enough clearance around all sides of the pattern. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhykYdhRpYwkywm5B0_Xact1wt_w7W3ARoVb1EPC_t89Lcl_DOszgL5jdx8g1VY1rgKuwA8Navq8m0nc4bkBqVzKgDw_kt2hNJ1fLzOwFjKohLqhvR4TSX-gg97HWtCLETikBVPNq1z8gU/s1600/Img_1637.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhykYdhRpYwkywm5B0_Xact1wt_w7W3ARoVb1EPC_t89Lcl_DOszgL5jdx8g1VY1rgKuwA8Navq8m0nc4bkBqVzKgDw_kt2hNJ1fLzOwFjKohLqhvR4TSX-gg97HWtCLETikBVPNq1z8gU/s640/Img_1637.jpg" width="480" /></a></div> Marco then gave the pattern a good dusting with talc parting powder to make sure the pattern would easily release from the green sand when the pattern was lifted out of the drag-half of the mold. He next riddled a fine layer of green sand over all of the pattern, ramming the sand with his fists as he covered the pattern. If he had used an air-ram at this point, he would have cracked the pattern. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj9HnTOJeYNC_I8F1PYB-fIOPwDWt6DLKVyi_HXewiJ-x87X4D_D45qpLATTAvzG_VS8RLHiV6oNRtoaE_rquT7ePsE80NiEBwwYYNUn6VS9sFulYC8w5CUWCKER20EuY14QbVXa8tI3FU/s1600/IMG_1639.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj9HnTOJeYNC_I8F1PYB-fIOPwDWt6DLKVyi_HXewiJ-x87X4D_D45qpLATTAvzG_VS8RLHiV6oNRtoaE_rquT7ePsE80NiEBwwYYNUn6VS9sFulYC8w5CUWCKER20EuY14QbVXa8tI3FU/s640/IMG_1639.JPG" width="640" /></a></div>He continued layering in green sand, making sure it was rammed tightly into the drag. At this stage, he started to use the air-ram to make sure the drag was well packed. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAczoIDnGOdJK_rJutfjRozfBp-4rg_5lI74VU3KNnWeeIwqPo_SNTOK8NlrIXTRqF9mt86uhwSpBa2t-1aZS7XR8OABIcpVP7YIEouR1A1C87FgKP5QwTTyrf68ilJn-uihZfoEa5P20/s1600/Img_1643.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="244" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAczoIDnGOdJK_rJutfjRozfBp-4rg_5lI74VU3KNnWeeIwqPo_SNTOK8NlrIXTRqF9mt86uhwSpBa2t-1aZS7XR8OABIcpVP7YIEouR1A1C87FgKP5QwTTyrf68ilJn-uihZfoEa5P20/s640/Img_1643.jpg" width="640" /></a></div>When the drag was full, he struck off the excess green sand and called on Paul and another worker to turn the drag over. The whole affair - pattern, sand, drag and mold board - weighed about 400 pounds.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhBDP53pIgbK-ezSFThKAZMdx4VsJWz-w5rd2m8RIZjzrtWeryyay5QXPGq5nrsS9XYhQaHKXvAgMVsCYqAmixvJDI5L04YDLFed1RoREME15k5Kyp8cftX0N5VYkQ8C3ZL4LzeEGaJhvQ/s1600/IMG_1644.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhBDP53pIgbK-ezSFThKAZMdx4VsJWz-w5rd2m8RIZjzrtWeryyay5QXPGq5nrsS9XYhQaHKXvAgMVsCYqAmixvJDI5L04YDLFed1RoREME15k5Kyp8cftX0N5VYkQ8C3ZL4LzeEGaJhvQ/s640/IMG_1644.JPG" width="640" /></a></div>With the drag and pattern now face-up, he gave the pattern and the top of the drag-surface of the mold a good dusting of talc parting powder to make sure the cope-half of the flask would readily lift off of the drag-half.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjWocR7UC4wqPrkuAm3MifzZ2SBhOJpSs4q9bYelxO9Rem8yZDMIiLFIyQFEn0g2UQhxzWizXvfndcdEQ2Cg_dS4Ojnap3zR2BCV6HBnvBcR1sLfqT9ybugtY6qPGNHIYYJa4yPTxzlJq4/s1600/IMG_1645.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjWocR7UC4wqPrkuAm3MifzZ2SBhOJpSs4q9bYelxO9Rem8yZDMIiLFIyQFEn0g2UQhxzWizXvfndcdEQ2Cg_dS4Ojnap3zR2BCV6HBnvBcR1sLfqT9ybugtY6qPGNHIYYJa4yPTxzlJq4/s640/IMG_1645.JPG" width="640" /></a></div><div class="separator" style="clear: both; text-align: center;"></div>He next placed the cope-half of the flask on top of the drag and riddled a layer of green sand on top of the pattern. Again, using his fists so as not to crack the pattern, he rammed the green sand all around the pattern.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiBSm_D7gG46sf-pHGCNMoi2bKwDLyis0d7plYIc6cAU96azszdxt8m_IQhaeO-eUlKb03BO-ThwherdSNOWgR43mS1aWQAaRQRH7F1fcAcqmIsL9hNiealE3ud9h-KyZV-duYD6K8kG0A/s1600/Img_1646.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="244" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiBSm_D7gG46sf-pHGCNMoi2bKwDLyis0d7plYIc6cAU96azszdxt8m_IQhaeO-eUlKb03BO-ThwherdSNOWgR43mS1aWQAaRQRH7F1fcAcqmIsL9hNiealE3ud9h-KyZV-duYD6K8kG0A/s640/Img_1646.jpg" width="640" /></a></div> He next set some wedge-shaped chunks of steel on top of the pattern to create risers. As explained in a previous blog, the risers allow the molten aluminum to come up into the voids created by the wedges and allows the gases to escape as the aluminum cools. If the voids created by the risers are large enough, the voids also serve as a reservoirs of molten aluminum that keep the mold filled as the aluminum cools and shrinks.<br />
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He also added a sprue cutter to form a sprue that would be used to pour molten aluminum into the mold. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi5sElTqBR1jB7wmwK-F1Ri-aQrIUa_LbxvspzAzN1YN-6y12cuaQqH1ZU674DTDSu-n_VP0fg2InSQu_mBla5LZEOqyDMCrbOR9Ii7-Lvd9C9ax7ENgbar1Q8nhA2aVsR8dz4rmxyOMRc/s1600/IMG_1648.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi5sElTqBR1jB7wmwK-F1Ri-aQrIUa_LbxvspzAzN1YN-6y12cuaQqH1ZU674DTDSu-n_VP0fg2InSQu_mBla5LZEOqyDMCrbOR9Ii7-Lvd9C9ax7ENgbar1Q8nhA2aVsR8dz4rmxyOMRc/s640/IMG_1648.JPG" width="640" /></a></div>In order to create a sufficiently large reservoir of molten aluminum, he removed the chunks of steel used to create the risers and replaced them with large ceramic-like cylinders (the material is similar to that found in some professional back-yard foundries and kilns). He continued to add and ram more sand until the top of the cope was full. He next struck off any excess green sand and used a tamper to smooth the top of the surface. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMItmiTgPgxOuWg6Ox8H0bipuKtX4UEEPpdRqwBH1s3OsipeFKtVco5Wws_Jf9IY1LMXSX48Tp6QWKKH72WLTk_Y5orLdD2qC2NGxYDPqkorqJJDiFUVm0Whsh9lMKdgpafRPVvZxbrA0/s1600/Img_1650.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="244" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMItmiTgPgxOuWg6Ox8H0bipuKtX4UEEPpdRqwBH1s3OsipeFKtVco5Wws_Jf9IY1LMXSX48Tp6QWKKH72WLTk_Y5orLdD2qC2NGxYDPqkorqJJDiFUVm0Whsh9lMKdgpafRPVvZxbrA0/s640/Img_1650.jpg" width="640" /></a></div> Marco and another worker then lifted the cope off the drag while Paul rolled the drag out of the way. The cope alone weighed more than 200 lbs so it was strictly a "lift the cope", "roll the drag out of the way" (thank god for those rollers, eh!), and "set the cope on its side". A minimum amount of moves in a minimum amount of time. Any miscalculations and the cope would have ended up on the floor as a big pile of green sand. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKuXYLnbL3KgNKTYgRP5z2aCLNsKCDG3trOhV65Q93XYpNb1DPYoGky4_1WBfSC5sRvHvU5_DEyx9xhHNMYVbexyQFT2vkpMKP9X7Ug0JPUBoJEEVwYNd5x70N-1vsUST6I6jSw0IsQBk/s1600/IMG_1653.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKuXYLnbL3KgNKTYgRP5z2aCLNsKCDG3trOhV65Q93XYpNb1DPYoGky4_1WBfSC5sRvHvU5_DEyx9xhHNMYVbexyQFT2vkpMKP9X7Ug0JPUBoJEEVwYNd5x70N-1vsUST6I6jSw0IsQBk/s640/IMG_1653.JPG" width="640" /></a></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg7aVtcS-svbsQof61MiK1kadXyOQASjV6IixM1k3WdHph11bMuMvC9XOeHwnyAdUp6vGTYEKkF3rhSPBPMAVU5TN7ZZ2vmLMuAk8Mogiqpbqmxtw1TtIYACinVecdkoKWglrLxaQFBW9I/s1600/IMG_1654.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg7aVtcS-svbsQof61MiK1kadXyOQASjV6IixM1k3WdHph11bMuMvC9XOeHwnyAdUp6vGTYEKkF3rhSPBPMAVU5TN7ZZ2vmLMuAk8Mogiqpbqmxtw1TtIYACinVecdkoKWglrLxaQFBW9I/s640/IMG_1654.JPG" width="640" /></a></div> They next lifted that 150 lb pattern out of the drag. It was definitely not an easy job as it took three of them to do it. Here's what the drag-half of the mold looks like. You can see the pattern in the mold that carries all of the fine detail of the original "patio stone" rock. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg5x0G6Ut3Gv4M0cHJNLVvT8mDnFnSxC7YtgL-c6qN7isCMtOLBUzCpDfiPoR5BVd6iqhKeid4KnzbG7xhs5VOLS5-H_hGN1RTEqnQsw72HF31b3sDjhL2bLderPtEgtPtXpotiHT-ejPY/s1600/IMG_1655.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg5x0G6Ut3Gv4M0cHJNLVvT8mDnFnSxC7YtgL-c6qN7isCMtOLBUzCpDfiPoR5BVd6iqhKeid4KnzbG7xhs5VOLS5-H_hGN1RTEqnQsw72HF31b3sDjhL2bLderPtEgtPtXpotiHT-ejPY/s640/IMG_1655.JPG" width="640" /></a></div>But first Paul and Marco worked on the cope-half of the pattern cleaning and blowing off the loose sand and fixing any imperfections that might have been on the cope-half of the pattern. After cleaning out the holes for the sprue and risers, they cut gates into the mold so that the molten aluminum would flow evenly and continuously into the mold. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhtn1h14Be0XhgmkNbpEC9k84Gq9zx2k_8scNzSs1hdnrfYwMHi9caX5pXmmMKnhF1E8IAUf7osgkOkXlEbwnokO3faPXeJRCY1citVuXB7530Vv5uQL7bSmiM3lErKSx7N_pEAff-GCEA/s1600/IMG_1656.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhtn1h14Be0XhgmkNbpEC9k84Gq9zx2k_8scNzSs1hdnrfYwMHi9caX5pXmmMKnhF1E8IAUf7osgkOkXlEbwnokO3faPXeJRCY1citVuXB7530Vv5uQL7bSmiM3lErKSx7N_pEAff-GCEA/s640/IMG_1656.JPG" width="640" /></a></div>Marco and Paul next turned their attention to the drag-half of the pattern, blowing off the loose sand and cleaning up any imperfections. They had to cut into the sides of the green-sand mold to remove the pattern but these were easily fixed up with handfuls of green sand and smoothing with a trowel. <br />
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They next placed the cope back on top of the drag. They clamped the four corners of the flask so that the cope wouldn't "float" off the drag when the molten aluminum was poured into the mold. The mold was now complete and ready for the aluminum pour.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjeJRi3Vndf83CEENc-qdE-YnurMQTULrdbrbrGM2HiWYsTKJgU8xmvLL3wrCdgINFEmP5kD8sGnfnku85olloxEHQ8IE8n4fKnxqp-LPzsRDPz7yS3dp-RJ3YiFY72dLcQ9fNkaHAqvV8/s1600/Img_1658.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="474" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjeJRi3Vndf83CEENc-qdE-YnurMQTULrdbrbrGM2HiWYsTKJgU8xmvLL3wrCdgINFEmP5kD8sGnfnku85olloxEHQ8IE8n4fKnxqp-LPzsRDPz7yS3dp-RJ3YiFY72dLcQ9fNkaHAqvV8/s640/Img_1658.jpg" width="640" /></a></div>The key thing in an aluminum (or any) pour is to keep a steady "flow" of molten aluminum pouring into the mold - particularly with a mold this large. It took two "pots" and 6 "ladles" of molten aluminum to fill the mold and to leave a good supply of molten aluminum in the risers. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjeSUfXlv_i96x_JizhFw0yMBjFn3jk3pE61zAScIhyIlNWVhAMl1tiugfcU4gWkCNG8wUvUiZIUb8Yh6h9qzY8XuqAASHr4HRVGc0Ol5mSIu0qOVLeVsuS0HXWKFmFvySkr4OSKw9Z55M/s1600/Img_1659.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="244" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjeSUfXlv_i96x_JizhFw0yMBjFn3jk3pE61zAScIhyIlNWVhAMl1tiugfcU4gWkCNG8wUvUiZIUb8Yh6h9qzY8XuqAASHr4HRVGc0Ol5mSIu0qOVLeVsuS0HXWKFmFvySkr4OSKw9Z55M/s640/Img_1659.jpg" width="640" /></a></div>Marco then "babysat" the mold for the next 45 minutes periodically pouring a ladle or two of molten aluminum into the top of the riser tubes as the aluminum in the mold cooled, drawing down the reservoir of molten aluminum in the riser tubes.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiPj0k1RF-4u-2-goLPQ1U0qlUNoz89N4HsBi00HH1rnLGZHiEFAiegGpZJ1elbAYorH-Elfq0iCspXPd1DsMxljsN92PF5E5vo88MfLtLdPJFcm88GQ_zn5ZHEYnZcSGDbFSXJDG9Ew6k/s1600/IMG_1662.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiPj0k1RF-4u-2-goLPQ1U0qlUNoz89N4HsBi00HH1rnLGZHiEFAiegGpZJ1elbAYorH-Elfq0iCspXPd1DsMxljsN92PF5E5vo88MfLtLdPJFcm88GQ_zn5ZHEYnZcSGDbFSXJDG9Ew6k/s640/IMG_1662.JPG" width="640" /></a></div>After a couple of hours, the casting had cooled sufficiently to knock it out of the green sand mold.<br />
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The flask was upended and the casting pulled out of the green sand. The green sand was steaming hot. Don't touch! It will badly burn your fingers to a crisp before you can say "Ouch!!".<br />
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<div class="separator" style="clear: both; text-align: left;">After letting the casting cool overnight, it was moved over to the clean-up part of the shop where Paul wire-brushed the remaining green sand off the casting. <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhU2hJvfzi755PhrXsVoRBEt0QdC1d20b5ExEiAnAqBYd5QGYXOx2qexWvr_n8lRYVmI5DmqPWUrJ5ZPj5W3jJLYleUsP_qEjar0FHIGG7NyAYIJk5NPWBvf-UQPqp4ij5tQuAEIgSntjE/s1600/Img_1670.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="228" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhU2hJvfzi755PhrXsVoRBEt0QdC1d20b5ExEiAnAqBYd5QGYXOx2qexWvr_n8lRYVmI5DmqPWUrJ5ZPj5W3jJLYleUsP_qEjar0FHIGG7NyAYIJk5NPWBvf-UQPqp4ij5tQuAEIgSntjE/s640/Img_1670.jpg" width="640" /></a></div>Once the green sand had been brushed off, you could clearly see the detail of the rock in the aluminum casting. The sodium silicate and silica sand had clearly captured the detail of the "patio stone" rock. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiggh5-975bjIQkqZIYoKPjJXgg3tcYMiXADYVktQ4FLgWnLBpZlKK5fNLl8BbTc_133RvbVbuhnbs8NHLXXX4gtI5_pp0b4BjyeCuB__HCJ5XO7fpomk5UPjooDmY6pj0TlBM_x67F7vE/s1600/IMG_1673.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiggh5-975bjIQkqZIYoKPjJXgg3tcYMiXADYVktQ4FLgWnLBpZlKK5fNLl8BbTc_133RvbVbuhnbs8NHLXXX4gtI5_pp0b4BjyeCuB__HCJ5XO7fpomk5UPjooDmY6pj0TlBM_x67F7vE/s640/IMG_1673.JPG" width="640" /></a></div>Next, the sprues and risers (now solid) were cut off and any sharp edges on the sides of the casting ground down.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgBD0lnlL7XZoaqHbT5ItTOlOb_b_AWMIYcJVtFi7pLW7d7tmLeexUiPls9HknHhjtF9YDey5ZlV1fZMWFGlamXC4eCfU1y069QVOl_taxv57xy4QhYc6KRnYozfadK3Lr3rmKGmm8Kig8/s1600/Img_1677.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="362" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgBD0lnlL7XZoaqHbT5ItTOlOb_b_AWMIYcJVtFi7pLW7d7tmLeexUiPls9HknHhjtF9YDey5ZlV1fZMWFGlamXC4eCfU1y069QVOl_taxv57xy4QhYc6KRnYozfadK3Lr3rmKGmm8Kig8/s640/Img_1677.jpg" width="640" /></a></div>The casting was next transported over to the weigh scales and weighed. <br />
110 pounds of solid aluminum, ready to receive the concrete slurry to make "patio stone" rocks.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiSkLD7moLt2Br_lFa4QzB-nMyzilvXuLZPaxXdlX_2Ahb6MHEh8hAlGQJ9N4hL5N_fyZ8aJ9D8qkbUdwO_2KaejXQzsJoLb-onUJFyCdne2YOlorrzmO-eHZIdwJyUVz1-zrgJU6emtMo/s1600/Img_1674.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="252" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiSkLD7moLt2Br_lFa4QzB-nMyzilvXuLZPaxXdlX_2Ahb6MHEh8hAlGQJ9N4hL5N_fyZ8aJ9D8qkbUdwO_2KaejXQzsJoLb-onUJFyCdne2YOlorrzmO-eHZIdwJyUVz1-zrgJU6emtMo/s640/Img_1674.jpg" width="640" /></a></div>A job well done! And I had a first-hand look at how aluminum castings are made.Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2481033622229007011.post-489997667551085602010-05-03T17:53:00.000-07:002011-12-30T06:25:14.421-08:00Sand Cores Using Sodium Silicate and Carbon Dioxide (CO2)Sand, when mixed with the correct ratio of sodium silicate, rammed into a core box, and then exposed to carbon dioxide (CO<span style="font-size: xx-small;">2</span>), will result in a very hard and durable sand core. Never having used sodium silicate (and never having made sand cores before!), this was an excellent lesson in learning what works and what doesn't. <br />
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<a href="http://www.pqcorp.com/technicalservice/literaturelist.ASP">PQ Corporation</a> is the largest manufacturer of sodium silicates, one of the most widely used chemicals in the world. <a href="http://www.pqcorp.com/literature/sodiumsilicates.pdf">Their brochure on sodium silicate</a> has this table which describes the various strengths of sodium silicate available. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiONTCTed5KgIOVeYXEGaoTUtdWE_MJi27Dpw5GHPZLIzIDrk8Dpx4IhsF3ZqCLQ2rz6bYPx63Mb46EqKymPBisWQRxmnkCQzgwUROyXOcfds8AodJAhrLjVO_hdN4VQJSjgUyQFLsMBA0/s1600/99+Sodium+Silicate+Properties+Table.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="236" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiONTCTed5KgIOVeYXEGaoTUtdWE_MJi27Dpw5GHPZLIzIDrk8Dpx4IhsF3ZqCLQ2rz6bYPx63Mb46EqKymPBisWQRxmnkCQzgwUROyXOcfds8AodJAhrLjVO_hdN4VQJSjgUyQFLsMBA0/s640/99+Sodium+Silicate+Properties+Table.jpg" width="640" /></a></div><b><u>N-Grade Sodium Silicate</u></b><br />
The key measure of sodium silicate is the weight ratio of its two major components - <u>S</u>ilica <u>DiO</u>xide (SiO<span style="font-size: xx-small;">2</span>)to <u>S</u>odium <u>O</u>xide (Na<span style="font-size: xx-small;">2</span>O) (the column titled "Wt. Ratio SIO<span style="font-size: xx-small;">2</span> / NA<span style="font-size: xx-small;">2</span>O"). The most commonly available sodium silicate has a weight ratio of 3.22 parts of Silica DiOxide to 1 part of Sodium Oxide with a solids content (active ingredients) of 37.6% (8.90+28.7=37.6 from Table 2 above). The rest (62.4%) is water. This is sold as "N" grade sodium silicate and is NOT the best choice for making sand cores as it doesn't provide very good strength to the sand core. The sand core will slowly disintegrate when handled. This type of sodium silicate has the viscosity of a cheap liquid dishwashing soap. Table 2 above describes it as a syrupy liquid. <br />
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I made the mistake of using the 3.22 N-grade sodium silicate (it may even have been a weaker solution) with very poor results. Even after 24 hours and constant exposure to CO2, the sand cores wouldn't hold together. For those that did stick together, I would end up with loose sand grains in my hand whenever I handled them. <br />
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<b><u>RU-Grade Sodium Silicate</u></b><br />
The best type of sodium silicate for making sand cores has a weight ratio of 2.40 parts of Silica DiOxide to 1 part of Sodium Oxide with a solids content (active ingredients) of 47.05% (13.85+33.2=47.05 from Table 2 above) - a 25% increase in active ingredients over the N-Grade stuff!! This is typically sold as "RU" grade sodium silicate and has the viscosity of concentrated liquid laundry detergent - it pours very slowly. Table 2 describes it as a heavy syrup. <br />
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I got some 2.4 RU-grade sodium silicate from CM and today mixed up a batch of sand to make some sand cores. <br />
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<b><u>Mixing The Sand And Sodium Silicate</u></b><br />
I first got all of my supplies, cups, bags, and stir sticks together and laid them all out on a sheet of plastic to make the cleanup easier. (The McDonald's cup is my supply of sand - easier to pour from a small cup than from a 25 kg bag, eh!?) I then put a smaller sheet of plastic down on top of the larger sheet so that I could easily recover any spilled sand.<br />
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To make the sand cores, I first filled the core box with dry 90m silica sand and poured it into a Ziploc bag. I added about 10% more dry sand as it will compact more when the sodium silicate is added to the mix.<br />
<div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjnzol1_uFpGSjB7Noq3lDCigcg4S1ipQbui3HF8PViUVR5SIEQbRm_XWdCCfG_iCtxRcmnUiEa8j86XanoLLAb2DrNBg7XKdRn8y6Cv_69aA9M3ejDpgmUvPBCqrOPuD-Fg-kyaIPGN8E/s1600/IMG_1679.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjnzol1_uFpGSjB7Noq3lDCigcg4S1ipQbui3HF8PViUVR5SIEQbRm_XWdCCfG_iCtxRcmnUiEa8j86XanoLLAb2DrNBg7XKdRn8y6Cv_69aA9M3ejDpgmUvPBCqrOPuD-Fg-kyaIPGN8E/s640/IMG_1679.JPG" width="640" /></a></div>Using my Canadian Tire "Star-Frit" scale, I weighed the baggie at 376 grams.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZscsRYN7wlcROJmPU_TMu6VHOfDB_LuHGP4DlLi-Fgjo73Lu24cyycwmqmlm400XNxnPZI2GUNw13-KnI9x_OoUUdf5ixbPRmQtCCqY91P76BX2RJ9OPGLEHaeuNX0YTnfhaHP2rFMUA/s1600/Img_1681.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZscsRYN7wlcROJmPU_TMu6VHOfDB_LuHGP4DlLi-Fgjo73Lu24cyycwmqmlm400XNxnPZI2GUNw13-KnI9x_OoUUdf5ixbPRmQtCCqY91P76BX2RJ9OPGLEHaeuNX0YTnfhaHP2rFMUA/s640/Img_1681.jpg" width="640" /></a></div>I put an empty plastic cup (clean and dry!) on the scale and zeroed it out.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEioBa3knzrfj1WUvKPsm5nmH3NWoIpTXbkUze25To1iJVeSYsVe3N65FSjUQqDdcVlE0OAcZQYqmm2tTL7NDn_wE3X1hhLF4GkGtg6KzWJhOZrENNySGdgu_433wdDEGclNRraRRmGEZaQ/s1600/Img_1683.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="238" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEioBa3knzrfj1WUvKPsm5nmH3NWoIpTXbkUze25To1iJVeSYsVe3N65FSjUQqDdcVlE0OAcZQYqmm2tTL7NDn_wE3X1hhLF4GkGtg6KzWJhOZrENNySGdgu_433wdDEGclNRraRRmGEZaQ/s640/Img_1683.jpg" width="640" /></a></div>I next decanted 38 grams (10%) of 2.4 RU-grade sodium silicate from my large supply bottle into the cup.<br />
<div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div>I poured the liquid into the bag of sand and rolled the sand, sodium silicate, and bag between my hands until the sand and sodium silicate were well and uniformly mixed. The mixture felt only slightly damp but would clump together when squeezed. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwgyIlZD6YSlt3JS25O2zq-yiZAb9fJRGPlTvmuLHjhgUSw_iwUE3I6fPG_JuWlKTBVqLa4CJLpgFuGKbnwmd1A_u_phk_-tKQqDuju5lIk4Ruo7NZyu3d5bVOMqW_yCHepXVBuUwaI5s/s1600/Img_1685.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="238" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwgyIlZD6YSlt3JS25O2zq-yiZAb9fJRGPlTvmuLHjhgUSw_iwUE3I6fPG_JuWlKTBVqLa4CJLpgFuGKbnwmd1A_u_phk_-tKQqDuju5lIk4Ruo7NZyu3d5bVOMqW_yCHepXVBuUwaI5s/s640/Img_1685.jpg" width="640" /></a></div><br />
<b><u>Stuffing The Core Box</u></b><br />
To make sure the CO<span style="font-size: xx-small;">2</span> would penetrate the sand core, I placed 1/4" steel rods into the middle of the core box so that I would have holes through the middle of the sand core. I spooned a small amount of sand mix into the core box and rammed the sand mix around the sides of the box and the steel rod.<br />
<div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhF0Rvg-rFEMyNP5VCGCqFr_Or46OgB4mGyiPAr8fWmrcOHiGGrfiWv1IgM_BTwyVSnXH-zcKTfQt83taw7x_bcA-vkssHth-1bVidPvvAudmu-lDimh_Ulr3EoPygbWFO6CaQI5jp_4SQ/s1600/Img_1688.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="244" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhF0Rvg-rFEMyNP5VCGCqFr_Or46OgB4mGyiPAr8fWmrcOHiGGrfiWv1IgM_BTwyVSnXH-zcKTfQt83taw7x_bcA-vkssHth-1bVidPvvAudmu-lDimh_Ulr3EoPygbWFO6CaQI5jp_4SQ/s640/Img_1688.jpg" width="640" /></a></div>More sand mix, more ramming until the core box was filled to the top. I struck the sand mix level with the top of the core box and lightly patted the sand mix so that it was firmly compacted across the top. With a twist, I removed the steel rods from the middle of the sand core leaving nice <span style="font-size: x-small;">1/4</span>" holes through the middle of the sand core.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhzM632UiN3km1N7HOFu4JOP9TUOY7SKY4YPkwAlQ26FEW7RAasKjQO-Fpu2xRu6CtpdNtUm-uwQBzyaL4we56n3k8R37Tsf5TKDnZvnXBMFfln30fsM5ePu0ZcMVOoKtb8AbIAcA21Uto/s1600/Img_1690.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="238" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhzM632UiN3km1N7HOFu4JOP9TUOY7SKY4YPkwAlQ26FEW7RAasKjQO-Fpu2xRu6CtpdNtUm-uwQBzyaL4we56n3k8R37Tsf5TKDnZvnXBMFfln30fsM5ePu0ZcMVOoKtb8AbIAcA21Uto/s640/Img_1690.jpg" width="640" /></a></div><b><u><br />
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<b><u>Using The CO<span style="font-size: xx-small;">2</span> Gas</u></b><br />
I wouldn't have believed it if I hadn't seen it in person but.... it only takes a few seconds of CO<span style="font-size: x-small;">2</span> gas to turn the loose sand into a hard sand block!! The secret is in how the CO<span style="font-size: x-small;">2</span> is applied to the sodium-silicate-sand mix.<br />
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On the right-side of the photo above, you can see a block of wood with a couple of holes in it. And, in the photo below, you can see a plastic container with a hole in the top. Using my blow gun attached to the CO<span style="font-size: x-small;">2</span> cylinder, and pressing down on the top of the plastic container, I slowly gave a 2-second shot of CO<span style="font-size: x-small;">2</span> into the container. This immediately hardened the surface of the sand core.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjx2KCt-hQFSHbPxRTYNClDL1ajpeyYZ_-n-Y8wZg2DO_CC2jvHqXYfqnynRwS94Do-NSVJt8aOmp77GJSarcXo-t_AQON6HnH1zSfO9MD31fyct9x91_uou-Xt9Djmzd4hcpTLGIaQSzQ/s1600/IMG_1700.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjx2KCt-hQFSHbPxRTYNClDL1ajpeyYZ_-n-Y8wZg2DO_CC2jvHqXYfqnynRwS94Do-NSVJt8aOmp77GJSarcXo-t_AQON6HnH1zSfO9MD31fyct9x91_uou-Xt9Djmzd4hcpTLGIaQSzQ/s640/IMG_1700.JPG" width="640" /></a></div>Removing the plastic container, I then placed the wooden block on the top of the core box, aligning the hole in the wooden block with the hole(s) in the sand core. I slowly gave each hole a 2-second shot of CO<span style="font-size: x-small;">2</span>.<br />
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I then undid the screws of the core box. Voila, the sand core easily separated from the sides of the wooden core box. In less than 20 seconds from the time of applying the CO<span style="font-size: x-small;">2</span> to starting to undo the screws, I had a solid sand core! Whoodathunkit, eh!!??<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgMjpIPSPNoSOAlKGyVQdhMpf9GlQuVgaKeCne-jNwvjqeb4KUeHrjI3uQD7nkyPFNueByxj2Mk5twE9ij-jY3EAwXBo5Ha9t-nDAurdtt5UwhjmqmCN6M8xzwPOXoopaca6-9mL35BeuI/s1600/IMG_1701.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgMjpIPSPNoSOAlKGyVQdhMpf9GlQuVgaKeCne-jNwvjqeb4KUeHrjI3uQD7nkyPFNueByxj2Mk5twE9ij-jY3EAwXBo5Ha9t-nDAurdtt5UwhjmqmCN6M8xzwPOXoopaca6-9mL35BeuI/s640/IMG_1701.JPG" width="640" /></a></div>I then repeated the CO<span style="font-size: x-small;">2</span> process for my second sand core. The solidified sand core easily slid from the core box.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEixVdJO-KacH6cn9B6NCfdV-t01GFDjZdVcuhv46gCbgzn9SHvLjXRTlqPEjp4ysuaAQ5DVr3zXQzh4o6nQsNonv64K4Rs4weOaKk6pYAh1ECH8VAdbjGSrdqQeJYCgBz4y_H8QVDAcnfI/s1600/04+Sand+Cores-08.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEixVdJO-KacH6cn9B6NCfdV-t01GFDjZdVcuhv46gCbgzn9SHvLjXRTlqPEjp4ysuaAQ5DVr3zXQzh4o6nQsNonv64K4Rs4weOaKk6pYAh1ECH8VAdbjGSrdqQeJYCgBz4y_H8QVDAcnfI/s640/04+Sand+Cores-08.jpg" width="640" /></a></div><br />
<div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div><b><u>Ratio of Sodium Silicate To Sand (By Weight!!) Is Very Important!!</u></b><br />
The whole secret in using sodium silicate is in the sand mix and the application of the CO<span style="font-size: x-small;">2</span>.<br />
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In my first try at using sodium silicate, I was short about 3 tablespoons of sand mix. I hastily mixed up a small batch that had about 30% sodium silicate. Bad news!! It wouldn't hold its strength even when repeatedly exposed to the CO<span style="font-size: x-small;">2</span>. The sand core was still as soft as when I had rammed it into the core box. I presume the extra liquid prevented the CO<span style="font-size: x-small;">2</span> from penetrating the sand core. So, whether you use a 6% ratio or a 10% ratio, the relative ratio (by weight) of sodium silicate to sand is very important. It doesn't take a lot of sodium silicate. <br />
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<b><u>How You Apply The CO<span style="font-size: x-small;">2</span> Is Very Important!!</u></b><br />
While CO<span style="font-size: x-small;">2</span> is heavier than air, my first attempts at using sodium silicate weren't that good. I placed the wet sand cores into a plastic bag and applied the CO<span style="font-size: x-small;">2</span>. On my trip to Alumaloy Castings, I saw how they applied the CO<span style="font-size: x-small;">2</span> to the sand - a small cup-like device attached to their CO<span style="font-size: x-small;">2</span> hose, and a piece of wood with a hole in it held on top of the sand core and aligned with the holes in the sand core. A couple of 2-3 second shots of CO<span style="font-size: x-small;">2</span> and the sand core was as solid as a rock.<br />
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It was obvious I needed to apply the CO<span style="font-size: x-small;">2</span> in a more "aggressive" fashion. So I modified my process using a 1-litre plastic container with a hole drilled in the top. I was then able to drive the CO<span style="font-size: x-small;">2</span> right into the exposed surfaces of the sand cores.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhhhzv4KF-H4ieUA6RbcgTsfp0j2NilDTr2ZCqKHWDkDwIYMgMXScF3bIlMCzH_RjpV7qzzkTeJH5bMdw7nruNFajtedGYKVlsNa3tjLXGaHs87A6TGdM_aUJWOlC7YXpO-9Slwn-xfoHI/s1600/08+Plastic+Cup+w+CO2.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhhhzv4KF-H4ieUA6RbcgTsfp0j2NilDTr2ZCqKHWDkDwIYMgMXScF3bIlMCzH_RjpV7qzzkTeJH5bMdw7nruNFajtedGYKVlsNa3tjLXGaHs87A6TGdM_aUJWOlC7YXpO-9Slwn-xfoHI/s640/08+Plastic+Cup+w+CO2.JPG" width="508" /></a></div>To get the CO<span style="font-size: x-small;">2</span> into the holes created by the <span style="font-size: x-small;">1/4</span>" steel rods, I simply drilled a couple of holes into a piece of <span style="font-size: x-small;">1/4</span>" plywood so that I could drive the CO<span style="font-size: x-small;">2</span> right through the middle of the sand cores.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj1ecpbed-buz5dVnuSUx5hy1zeOm09VzhtSWCH09wcSWnS4UoEOhTmyJj3peT6DqvFpV27BDniQdihF1OAcITsEijkYaiaiACrbRypyz8Nwxdo_o25mQGQgP0uE9cRznKZpv6Xj3SX3pE/s1600/04+Plywood+Block+w+Holes.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="358" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj1ecpbed-buz5dVnuSUx5hy1zeOm09VzhtSWCH09wcSWnS4UoEOhTmyJj3peT6DqvFpV27BDniQdihF1OAcITsEijkYaiaiACrbRypyz8Nwxdo_o25mQGQgP0uE9cRznKZpv6Xj3SX3pE/s640/04+Plywood+Block+w+Holes.jpg" width="640" /></a></div>Bigger sand cores? Simply use a bigger plastic container. These sand cores were almost instantly as hard as a brick with very smooth surfaces and sharp edges. <br />
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In any event, I'm very pleased with the results. Now we go into full-scale production with the sand cores using sodium silicate and CO<span style="font-size: xx-small;">2</span>.<br />
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<div class="separator" style="clear: both; text-align: center;"></div>Unknownnoreply@blogger.com15tag:blogger.com,1999:blog-2481033622229007011.post-14909805767573197782010-04-14T19:16:00.000-07:002010-04-25T11:22:50.315-07:00Patterns Finished!!Got the patterns finished today. The original casting on the right and one of the patterns on the left. The extra blocks of wood on each side of the wings and the two protrusions on the top are for the sand cores. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1fcxsCR0mlsE2UFz2HALjnq2TJKWYSxdAWmHnJ9-sFS4EfGHJyyaukv0OmCYjonvXG-3w0jgBXjidY9ykohgQeEvoZiD_gD2t-cuOYCLN1QY8-fh5zXK7wfnVikX1j-WRA6mbKyznj8w/s1600/Image012.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="292" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1fcxsCR0mlsE2UFz2HALjnq2TJKWYSxdAWmHnJ9-sFS4EfGHJyyaukv0OmCYjonvXG-3w0jgBXjidY9ykohgQeEvoZiD_gD2t-cuOYCLN1QY8-fh5zXK7wfnVikX1j-WRA6mbKyznj8w/s640/Image012.jpg" width="640" /></a></div><br />
Top view<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgpIpnTAE583axfWmrl0Om_08XsO1X-dk4T6eto1L0NyzKrW8_zGz3QF5jLbwbhfNjDBTXdJw3Zt1Htq84YlpCLQ_XPwpeyajjx1ZSmWBTZ61IPuTJ97i-zMo21rO9pBbgMUXwCInCfoEs/s1600/Image016.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="562" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgpIpnTAE583axfWmrl0Om_08XsO1X-dk4T6eto1L0NyzKrW8_zGz3QF5jLbwbhfNjDBTXdJw3Zt1Htq84YlpCLQ_XPwpeyajjx1ZSmWBTZ61IPuTJ97i-zMo21rO9pBbgMUXwCInCfoEs/s640/Image016.jpg" width="640" /></a></div><br />
Bottom view. The blocks on each side are core prints. These create voids in the mold that will hold the sand cores. This allows us to draw the pattern out of the sand without destroying the mold. The pink in the middle is body putty that we used to create fillets between the ribs and the base plate. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjW67jzng7a6Jx6drXSdvHbOlOuEjS8SruK860yKBNGTPpUGZQ_ZRxYnZtXL8xgtrETpVlTpi6de3N2e-P-MnlyIxOVEfHC8Wg7roAd4sqODYF8-6mwlXGISEHRUU4VKEnIJkIFF-Ermpw/s1600/Image014.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="588" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjW67jzng7a6Jx6drXSdvHbOlOuEjS8SruK860yKBNGTPpUGZQ_ZRxYnZtXL8xgtrETpVlTpi6de3N2e-P-MnlyIxOVEfHC8Wg7roAd4sqODYF8-6mwlXGISEHRUU4VKEnIJkIFF-Ermpw/s640/Image014.jpg" width="640" /></a></div><br />
The wing patterns. There's an extra piece of plywood on the side of each wing. This helps us to line the pattern with the base plate. Once we have holes drilled for our alignment dowels, these pieces will come off. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj9Cf87ng4tzSc3fn7ZjHqmqE6WQcxy6qEQcUSkGthWXKnqGGHcqLu2skXBIGawJfE50Bn4FF9Fzw_rTWnbBnE2HH0Mvn9i4unTleZFb7NxkJr8wCQW8fdcDF5Fkv-xWFHNzNcPmfVYYsE/s1600/Image013.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="198" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj9Cf87ng4tzSc3fn7ZjHqmqE6WQcxy6qEQcUSkGthWXKnqGGHcqLu2skXBIGawJfE50Bn4FF9Fzw_rTWnbBnE2HH0Mvn9i4unTleZFb7NxkJr8wCQW8fdcDF5Fkv-xWFHNzNcPmfVYYsE/s640/Image013.jpg" width="640" /></a></div><br />
Drilling holes for the dowel pins to keep the top half aligned with the bottom half. You can see that extra piece of plywood that we use for aligning the wing with the base plate on the left side of the wing. This piece will be removed once we have the holes for the dowel pins drilled. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjroidx1C9BUHEQ1Z4ktzaaYDL3sreOL6FNkXG5DC6mZP87DyOaYilT0f38Lur8Q4u5Spjbb4nlSiNDAt-J9a5N_-j536zkonP5OZvBFW0APHK0BGnh8gYU6g73-dwod7KKJdL1XBJ6wQs/s1600/Image017.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjroidx1C9BUHEQ1Z4ktzaaYDL3sreOL6FNkXG5DC6mZP87DyOaYilT0f38Lur8Q4u5Spjbb4nlSiNDAt-J9a5N_-j536zkonP5OZvBFW0APHK0BGnh8gYU6g73-dwod7KKJdL1XBJ6wQs/s640/Image017.jpg" width="480" /></a></div><br />
Once we have the alignment holes drilled, we glue 1/4" wooden dowels in the holes in the wing part of the pattern so that they protrude about 3/8". You can see them sticking out on the left side of the photo below. We next cut the dowels protruding on the top part (right side) of the wing pattern, then sand them so that they are flush with the top surface of the pattern. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjMQ1L5qmOAh4v2wtJaoqbDgP0F0BnAJxwGxlTQoWTtvA3e26Lb3O7EyxQUfgm5lSqC1CRNojrif85ajWGx9UjAO-4LBGLmYY7yE8by_XKlJ5G1tWURHA3iqF3X-QAWzRsfNVacfp-Ns4g/s1600/Image018.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjMQ1L5qmOAh4v2wtJaoqbDgP0F0BnAJxwGxlTQoWTtvA3e26Lb3O7EyxQUfgm5lSqC1CRNojrif85ajWGx9UjAO-4LBGLmYY7yE8by_XKlJ5G1tWURHA3iqF3X-QAWzRsfNVacfp-Ns4g/s640/Image018.jpg" width="480" /></a></div>Details of how we did it in the next couple of installments. Core boxes to be done next.Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2481033622229007011.post-49231439011908996972010-04-09T14:34:00.000-07:002010-07-20T05:20:44.465-07:00Step 1 - Fabricating the Base Plate Pattern.The BASE PLATE is an irregular shape that is based on a rectangular footprint measuring 5 <span style="font-size: x-small;">3/8</span>"x 11 <span style="font-size: x-small;">1/2</span>" and <span style="font-size: x-small;">1/2</span>" thick. On top of the base plate is the angular pad to which is fastened the rubber sweep. On the bottom of the pad are two rows of reinforcing ribs and a 3/4" mounting block which fastens the casting to the motor car.<br />
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The wooden pattern for the base plate is made from <span style="font-size: x-small;">1/2</span>" Baltic birch. Using the table saw, cut a rectangular piece of <span style="font-size: x-small;">1/2</span>" Baltic Birch measuring 5 <span style="font-size: x-small;">3/8</span>"x 11 <span style="font-size: x-small;">1/2</span>". <br />
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Using the existing aluminum casting, trace the pattern of the base plate onto a piece of stiff card stock. Retrace the lines on the card stock using a straight edge to make sure that all straight lines are parallel. Make a copy of the drawing and add the key measurements to the copy.<br />
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An additional pad will have to be included in the base plate underneath the upper part of the wing. This pad will serve as a platform to mount the core prints. The base plate pattern should look like this. <br />
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiFofm5stq0xVSyV2xO50riucH7tmbYmvUrk6QXSRQTaFqr1nk1fwmJ9_wIJu2Lhsi7z7niRYVM-IUEfTBMKkMOQDwZu63z6jZBI-8DV9u-7ko8vu4R-p02nwBhmOWN_D7RARnK_GKYnBg/s1600/11-1+Base+Plate+Dimensions+600+x+1011.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="380" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiFofm5stq0xVSyV2xO50riucH7tmbYmvUrk6QXSRQTaFqr1nk1fwmJ9_wIJu2Lhsi7z7niRYVM-IUEfTBMKkMOQDwZu63z6jZBI-8DV9u-7ko8vu4R-p02nwBhmOWN_D7RARnK_GKYnBg/s640/11-1+Base+Plate+Dimensions+600+x+1011.jpg" width="640" /></a><br />
Cut out the copy of the card stock, leaving all lines in.<br />
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The base pattern is cut out of the birch plywood using the band saw. Use the band saw fence to make sure that straight lines are cut. Free-hand cut the inside curves. DO NOT CUT THE OUTSIDE CURVES! These will be cut after the ribs and mounting block have been glued and fastened to the base plate.<br />
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Sand the inside curves to produce a smooth finish.Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2481033622229007011.post-63001088317640335802010-04-09T14:31:00.003-07:002010-04-09T14:31:54.695-07:00filler 12sdUnknownnoreply@blogger.com0tag:blogger.com,1999:blog-2481033622229007011.post-77273049661279858352010-04-09T14:31:00.001-07:002010-04-09T14:31:36.841-07:00filler 11nnnnnnnnnnnnnnUnknownnoreply@blogger.com0tag:blogger.com,1999:blog-2481033622229007011.post-74386703074367989322010-04-09T14:30:00.002-07:002010-07-20T05:34:55.095-07:00Parts of the Speeder SweepIf we carefully examine the speeder sweep, we can see that it is comprised of a series of distinct pieces and shapes. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_ZwfuD4NMpyAKuuBdEMRSrx8vZ9KK4hgQ2gwsFq9vELpAaxoYE19Dxz-wyk3Xp3FZB_iGiJaiV0xyjd36DH8Y7mRNvlXp5cPmE67JBPCFJvwCP4_UBCR0M-yYBxyP2221mMOEpP-g_hM/s1600/01-0+Profile+of+Speeder+Sweep.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="412" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_ZwfuD4NMpyAKuuBdEMRSrx8vZ9KK4hgQ2gwsFq9vELpAaxoYE19Dxz-wyk3Xp3FZB_iGiJaiV0xyjd36DH8Y7mRNvlXp5cPmE67JBPCFJvwCP4_UBCR0M-yYBxyP2221mMOEpP-g_hM/s640/01-0+Profile+of+Speeder+Sweep.jpg" width="640" /></a></div><br />
The sweep is built on a base that is 1/2" thick. To stiffen the base we have two L-shaped ribs. To fasten the sweep to the speeder, we have a 3/4" plate with a hole. The wing is another 1/2" thick piece with two slots in it. It is mounted on the base via a pedestal that is 20 degrees to the base. So our task will be to fabricate all of these bits and pieces, glue and nail them together. Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2481033622229007011.post-13571148042711253382010-04-09T14:30:00.000-07:002010-04-25T11:37:37.219-07:001.1 - Woodings Motor Car Sweep Bracket<b><u>1.1.1 Purpose of the Woodings Motor Car Sweep Bracket</u></b><br />
Sweep brackets are fastened on all 4 corners (front and back) of the Woodings motor car. Rubber sweeps are bolted to the brackets and hang below the motor car slightly touching the rails. As the car moves along the track, the sweeps remove rock and other obstructions that might be on the rails which could derail the motor car and injure the occupants. The right front and left front brackets are mirror images of each other as are the right rear and left rear brackets. Or, restated, the right front and left rear brackets are similar as are the left front and right rear brackets. We will need 4 aluminum castings - the right front and left rear being the same and the left front and right rear also being simlar. This means we will have to make 2 patterns, each being a mirror image of the other. As precision is not important for this casting, shrinkage of molten aluminum will be ignored. We will take the measurements from the existing casting when making the patterns. <br />
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<b><u>1.1.2 A Tour Of The Sweep Bracket</u></b><br />
An examination of the existing casting indicates that it is made up of 4 unique elements. <br />
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Firstly is the BODY on which the casting is built. This is shown in the photo below. While this consists of an irregular shape, it is built on a rectangular "footprint" measuring 5<span style="font-size: x-small;"> 3/8</span>"x 11 <span style="font-size: x-small;">1/2</span>". This fact will make the cutting of this part of the pattern relatively easy. <br />
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Secondly, the casting has an elevated WING mounted to the body at an angle of 20 degrees to the BODY. Rubber sweeps are bolted to the WING via 2 slots in the WING. <br />
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<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjxMtJU2AYf7S0RuUZwMZtlB_ej_SJjjig9AtICcyC-_jAQmwUxbyYF1MnufxMONtdr8zoLGKNODyiARohBEAEvoJX4XEKhiDarNvE5hkwO6DAJwGZmT2BigR9Stumd1sPUzGnnngi-n88/s1600/01+Top+View-2.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjxMtJU2AYf7S0RuUZwMZtlB_ej_SJjjig9AtICcyC-_jAQmwUxbyYF1MnufxMONtdr8zoLGKNODyiARohBEAEvoJX4XEKhiDarNvE5hkwO6DAJwGZmT2BigR9Stumd1sPUzGnnngi-n88/s640/01+Top+View-2.jpg" width="480" /></a></div><br />
Examining the underside of the casting in the photo below, we have two L-shaped RIBS that provide strength to the casting. In order to provide clearance for attaching the rubber sweep via bolts, the RIB on the left side is indented about 1/8" into the BODY of the casting. The right side of the BODY has also been recessed on an angle of 20 degrees to provide clearance for the bolts. At the bottom-right corner of the casting is a BOSS that is 3/4" thick. The casting is fastened to the motor car via a hole in the BOSS. To simplify the pattern and making of the mold, this hole will not be incorporated into the pattern as it is much easier to drill a hole after the parts have been cast. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0epZ-CIqp87JG0rf7rNEEZtK9EJJWQGMzJNHP6de27zqqZNYJoqZVuK5yVz_GYW7ZUYehCOiy8UzuA83-JsWjHZ0er6AAWvQyjngvLvtB5oxyNgPsue4GSLvK2DlkUzcfQTu5KhxvfbU/s1600/02+Bottom+View.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0epZ-CIqp87JG0rf7rNEEZtK9EJJWQGMzJNHP6de27zqqZNYJoqZVuK5yVz_GYW7ZUYehCOiy8UzuA83-JsWjHZ0er6AAWvQyjngvLvtB5oxyNgPsue4GSLvK2DlkUzcfQTu5KhxvfbU/s640/02+Bottom+View.jpg" width="400" /></a></div>The photo below shows the BODY incorporating the RIBS, the angle of the WING, and the hole in the BOSS on the left side of the photo. Note that the end of the BOSS is rounded which allows the casting to be swung away from the tracks when the motor car is being removed from the rails. We won't incorporate the top part of the rounding in our pattern as this would create an UNDERCUT in our mold. We will simply round this with the band saw after we have cast the part. We also get a good view of where we can establish the PARTING LINE when we make the pattern for the casting. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHzTptwIOnkz1vd2kT6c6Cb6rCBYE0Pe3K_rzRBHXDIOJ8ls6AsiqEZv3KFSP-vwGIdxwSzSqV5E4wbz5oB5GXZj6I5fo8PzILGkgEmhjMMr5RtRFf1f2yoCMe6e8pAfrEn7n-QJh2sdQ/s1600/03+Side+View-0.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="390" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHzTptwIOnkz1vd2kT6c6Cb6rCBYE0Pe3K_rzRBHXDIOJ8ls6AsiqEZv3KFSP-vwGIdxwSzSqV5E4wbz5oB5GXZj6I5fo8PzILGkgEmhjMMr5RtRFf1f2yoCMe6e8pAfrEn7n-QJh2sdQ/s640/03+Side+View-0.jpg" width="640" /></a></div><span style="font-size: small;"><b><u>1.1.3 Problems To Resolve With The WING</u></b></span> <br />
The casting is unique in that it is cast along two planes. The BODY, RIBS and BOSS of the casting covers a horizontal plane (the XZ-plane). The WING of the casting is sloped 20 degrees to the XZ plane. <br />
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If we rotate the above photo 180 degrees along the XZ-plane, we can see where we will have some problems to resolve in making the pattern as the WING of the casting will be embedded in the sand in both the COPE and DRAG. We will ruin our mold if we attempt to pull the embedded PATTERN from the sand. <br />
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<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEidDo_M3twrMzKLyAZLNS7gGhvnjgrwBMaxvys82byJ7YJF2_F4B7_HE_qeA_aDQiwPaCHi98cpxcs5Yfzb3TUxH4aVCJhhvJQ1nPtwXeco-CYZQBXS5yAdebEc3Y0kOlklid7pfJNDIbg/s1600/04+Side+View-1.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="362" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEidDo_M3twrMzKLyAZLNS7gGhvnjgrwBMaxvys82byJ7YJF2_F4B7_HE_qeA_aDQiwPaCHi98cpxcs5Yfzb3TUxH4aVCJhhvJQ1nPtwXeco-CYZQBXS5yAdebEc3Y0kOlklid7pfJNDIbg/s640/04+Side+View-1.jpg" width="640" /></a></div><br />
We can easily resolve our problem with the part of the WING embedded in the DRAG by simply having the parting line follow this part of the wing as shown in the photo below. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhDe8Z-bW9YJ-jVwoQjb8ZqpiYthxQxtHgFhUxLk3Fi_3vS8gfayWZoWnTBQOli-UVDhn_4qFcfaBHH0iQppZZAjVj0DI5O3MIy18t_lXs-XX9t386Cca49Js4yAH76u5aTVZvMeYCyNAY/s1600/13+Side+View-5.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="362" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhDe8Z-bW9YJ-jVwoQjb8ZqpiYthxQxtHgFhUxLk3Fi_3vS8gfayWZoWnTBQOli-UVDhn_4qFcfaBHH0iQppZZAjVj0DI5O3MIy18t_lXs-XX9t386Cca49Js4yAH76u5aTVZvMeYCyNAY/s640/13+Side+View-5.jpg" width="640" /></a></div><br />
In order to preserve the mold, we will have to fill in part of the PATTERN between the BODY and the WING so that we don't destroy the MOLD when we remove this revised PATTERN. These fillers will be the CORE PRINTS. We can subsequently fill in the hollow created by the filled part of the PATTERN with a specially prepared sand CORE which will give us our final outline of the casting we want to make. <br />
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SAND CORES are made in a specially prepared MOLD which is filled with a sand and glue mixture, baked to form a solid mass, and then inserted into the larger MOLD.<br />
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The photo below has been rotated 90 degrees in a counter-clockwise direction along the XZ-plane. We can clearly see the mounting hole in the BOSS and the 20 degree elevation of the wing. The RIBS have been seamlessly incorporated into the BODY of the casting. <br />
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXCqbIMA1cSaq60-cngv1ZWukWpdUwQUoDSVTpmTAPA4WW6dOSftKnQomDR3EVqVx9D2e0hCEbyAMba00wIkUJTqhoW9vtbUEMw0zijOjh4WzEwqbPwovbSTJO0_WfeXmvDwGsm7dW-y0/s1600/05+End+View-1.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="216" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXCqbIMA1cSaq60-cngv1ZWukWpdUwQUoDSVTpmTAPA4WW6dOSftKnQomDR3EVqVx9D2e0hCEbyAMba00wIkUJTqhoW9vtbUEMw0zijOjh4WzEwqbPwovbSTJO0_WfeXmvDwGsm7dW-y0/s640/05+End+View-1.jpg" width="640" /></a><br />
Our first step will be to fabricate the BODY of the pattern. We will next fabricate and incorporate the RIBS and BOSS into the BODY. Lastly, we will fabricate and incorporate the WING and CORE PRINTS into the PATTERN, remembering that we will have to also fabricate CORE BOXES in which to cast the sand CORES.Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2481033622229007011.post-38333741950695541192010-04-09T14:29:00.003-07:002010-04-09T14:29:26.912-07:00filler 8aaaaaaabbbcccccccccccccccUnknownnoreply@blogger.com0