How to Cast Metal Parts
Casting metal parts, while not easy, is an efficient means of ensuring you have secondary copies of original pieces. While casting does not always produce exact likenesses, beginner and novice casters are likely to see significant improvements on their work by practicing frequently and trying different chemical formulas for mold and mold release agents. Larger molds will likely require the assistance of additional individuals or lifting machinery.
Things You'll Need
- Item to be cast
- Casting flask
- Foundry sand
- Riddle sieve or screen
- Large hole cutter or 1/2" copper pipe
- 1/4 inch wooden dowel
- 1/8 inch wooden dowel
- 10 by 1 1/2 by 1 inch wooden rammer or striker
- Runner bar pattern
- Spoon
- Trowel
- Parting dust
- Foundry
- Metal Ingots
- Crucible
Instructions
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1
Apply a thick coating of parting dust to all visible sides of the item to be molded.
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2
Place the item to be molded in a flask large enough to allow for at least two or three inches of clearance on all sides. Add the dowels to the flask to create runner channels through which the metal will flow.
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3
Cover just the item to be molded by sieving sand through the riddle. When the item is fully covered, forgo the riddle and simply fill the remaining space in the flask with sand. Level any excess sand to the top of the flask.
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4
Paddle the sand to pack it down with the short end of the rammer, beginning with the edges and moving slowly towards the center of the sand in the flask. Use one hand to hold the flask in place.
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5
Fill more sand in to accommodate any gap left at the top of the flask, and continue pounding until further pounding does not compact the sand any more. Level the sand at the top of the flask again.
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6
Place a bottom board at the top of the mold, and holding it tightly to the flask, flip it over.
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7
Replace the cope and pattern board, re-applying parting dust and sand, and pounding them to compaction following the same steps as were used on the bottom of the flask.
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8
Remove the cope and set it aside after leveling it with the rammer.
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9
Fill more sand in to accomodate any gap left at the top of the flask, and continue pounding until further pounding does not compact the sand any more. Level the sand at the top of the flask again.
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10
Place a bottom board at the top of the mold, and holding it tightly to the flask, flip it over.
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11
Remove the cope and pattern board, and gently blow away any excess, loose sand, using the back of the spoon to smooth the edges of the sand around the item being molded.
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12
Replace the cope and pattern board, re-applying parting dust and sand, and pounding them to compaction following the same steps as were used on the bottom of the flask.
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13
Remove the cope and set it aside after leveling it with the rammer. Press the copper pipe into the bottom of the flask to form the sprue hole, and use the dowel to carefully smooth its edges.
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14
Carve a shallow indentation at the top of the sprue hole to hold pooling metal while it is being poured (also known as the pouring cup) with the spoon, and smooth this with the dowel as well.
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15
Tap both the runned and the item being molded with the heel of the rammer, and carefully remove them from the sand and replace the cope section of the flask.
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16
Light the furnace of the foundry. Heat it to the proper temperature for the metal or alloys being used, and make sure the furnace is burning properly.
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17
Fill the crucible with metal as quickly as it will take, and remove it only when red-hot, taking care not to overheat the metal.
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18
Carefully pour the metal into the mold, and allow it to cool for a minimum of 30 minutes.
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19
Shake the mold out, and carefully remove the cast piece. Cut off the gating metal, and grind and buff the finished piece to the desired appearance.
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20
Shake the mold out, and carefully remove the cast piece. Cut off the gating metal, and grind and buff the finished piece to the desired appearance.
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1
Tips & Warnings
Don't forget to temper your crucible, if needed; not tempering when required can greatly reduce its useful life.
Active foundries and molten metal are both used at extreme temperatures which can easily produce third degree burns. Every precaution should be used when handling or operating them.
