FOUNDRY From Start to Finish:
ARTIST'S CLAY ORIGINAL: Once the artist has created the original sculpture, usually in wax or clay, the process of turning this original into a limited edition bronze begins.
MAKING A MOLD: The first mold, referred to as the "mother mold," is made directly from the original clay sculpture, using coats of liquid rubber or silicon backed with plaster or fiberglass.
POURING A WAX PATTERN: Hot wax is poured into the latex rubber "mother mold" and allowed to cool for a short time. The wax is then poured out of the mold, producing a hollow wax copy of the original sculpture.
CHASING THE WAX: The wax pattern is carefully removed from the mold, inspected, and any flaws are painstakingly removed or "chased" by hand. A wax pouring cup and "sprues" are attached which will channel the molten bronze into the sculpture.
ATTACHING THE SPRUES: A pouring cup and wax shafts (known as "sprues") are attached to each part of the sculpture. These will ultimately serve as channels for the molten bronze to flow through after the wax has been melted out of the ceramic shell mold.
|CERAMIC SHELL MOLD: The second mold, a rigid ceramic shell, is formed by dipping the wax duplicate repeatedly in a vat containing liquid slurry and coating it with silica sand. This process takes several days. The shells are then fired in an oven to melt out the wax, and also to harden the ceramic shell mold for receiving the molten bronze.|
OUT THE WAX IN A KILN:
Once the ceramic shell has dried, it is fired in a kiln in order to
harden it, and also to cause the wax to melt out from within it, leaving
the mold hollow to receive the molten bronze that will be poured into
it in the next step of the casting process.
POURING THE BRONZE: Molten bronze is poured into the cup of the ceramic shell mold, into the space left behind by the "lost wax." The bronze will be allowed to cool, and then the ceramic shell will be broken off to reveal the bronze sculpture within.