- 1). Carve a wax model of the piece you wish to have. Make sure that the finished wax carving will fit inside the can that you have chosen to use to hold the resin mold.
- 2). Set the rubber mat down on a flat surface. This will be the base on which your resin will sit.
- 3). Place the sprue tree in the center of the rubber mat. The sprue tree is a piece of wax that acts as a base on which you can hold your wax carving.
- 4). Heat the top of the sprue tree with a heat gun and join it to your carving so that the joined piece stands freely. This takes a bit of practice but is very important because the wax cannot touch the can, or else the resin mold will not be completely contained and the molten silver will leak, ruining the piece.
- 5). Set the heavy metal can down around the sprue and the wax carving.
- 6). Don the respirator and rubber gloves.
- 7). Mix together equal amounts of silica investment powder and distilled water in a rubber bowl. Use an electric mixer on the low setting and mix the plaster until there are no lumps in it.
- 8). Pour the plaster into the metal can to cover the wax form. Allow the plaster to harden for three hours.
- 9). Place the plaster-filled can, sprue-side down, in a large pot on a slotted pot riser and then fill the pot with water to just below the riser level.
- 10
Boil the water on a stove for 30 minutes. This will cause the wax to melt out of the mold and leave an imprint on the interior. Let the metal can cool and then move it into a high-temperature furnace. - 11
Heat the can with the plaster to 2000 degrees Fahrenheit to vaporize any wax that remains in the mold; the can will glow orange to red. Allow it to cool for several minutes before removing it from the kiln. Wear heat-resistant gloves and remove the can with tongs. - 12
Set the plaster mold on the rubber mat. - 13
Fill a square crucible with sterling silver casting grain and place it in the kiln. Heat the crucible to 1650 degrees Fahrenheit and let the silver melt at that temperature for 15 minutes. - 14
Remove the crucible with tongs while wearing heat-resistant gloves. Immediately pour it into the sprue hole in the plaster cast. The silver will begin to solidify as soon as it hits the plaster. - 15
Dip the can with the plaster mold into a 5-gallon bucket of water using the tongs. The plaster will begin to dissolve. Do not remove the can for at least five minutes. - 16
Remove the can from the water and retrieve the cast silver design from the interior of the can; it will be black, with residual plaster stuck to the outside of the silver. - 17
Clean the excess plaster from the silver with a wire brush and a dental pick. - 18
Heat a solution of citric acid to 200 degrees Fahrenheit in a crock pot. - 19
Steep the silver in the citric acid solution for 12 hours. The silver will emerge with a chalky white finish. - 20
Fill a large glass bowl with water and one cup of baking soda. - 21
Remove the silver from the crock pot with tongs. Dip the silver in a water-and-baking-soda solution to neutralize the residual citric acid. - 22
Cut the sprue tree away from the silver design with heavy wire cutters. - 23
Grind down the area around where the sprue tree was attached with a rotary tool equipped with a grinding wheel. - 24
Place the silver piece in a rock tumbler with fine-grain abrasive. Run the tumbler through three full two-hour cycles. - 25
Remove the silver from the tumbler and buff it with a rotary buffing pad.