First I create an armature, which is the inner structure. This supports the clay used as a modeling medium. My armatures are usually made from wood and aluminum, however sometimes a stiffer metal is desired. If the piece is large, I'll incorporate styrofoam as well.
The piece is then modeled around the armature out of oil-based plastilina clay that stays pliable when uncovered. This is the part of the process that is the most time consuming, in order to create the intricate detail inherent in each piece. Models and/or photographs are often used.
When the original modeling is complete, a "mother mold" is made. This rigorous process can often destroy the original, so one must be very careful in its creation. The mother mold is like a three-dimensional puzzle with a hard exterior (plaster, fiberglass, etc.) and a flexible interior (a rubberized or latex material). I sometimes make my own, but usually prefer to have the assistance of a professional mold maker.
Upon completion of the mold, hot wax is poured or brushed into the negative, and then the entire piece is created again out of wax. The wax pieces are joined together and re-worked until the wax sculpture looks exactly like the original clay sculpture. This is also a lengthy procedure. If it is a very large piece, the wax sculpture will be left in refined pieces and welded together later after the metal casting.
I take the completed wax to the foundry and another "mold" or investment (made from plaster, sand and vermiculite) is coated over this finished wax. When a hard shell completely covers the wax, this investment is heated and the wax burns out. This leaves a negative, again, of the piece. Into this negative, molten metal is poured.
Now the finished metal work begins, and involves cutting, grinding and smoothing the casting.
When the raw casting is complete in its metal finishing, the patina (coloring) is applied. This process involves heating the piece with a torch and spraying specific chemicals, based on the color desired.
When the piece is finished, it is waxed and the sculpture is complete.