To begin, an armature is created which is
the inner structure. This supports the clay that is used as
a modeling medium. My armatures are usually made wth a wood
aluminum tubing, however sometimes a sturdier metal is desired. If
the piece is large, Styrofoam fastened by wire can be
incorporated in the armature to add bulk. Also, a
stronger interior metal such as rebar is used for larger
The piece is then sculpted out of oil-based plastilina clay
around the armature. This part of the process is the most
time consuming, as each piece is worked and reworked
until the artistic vision is achieved.
When the original modeling is completed, a "mother mold" is
made. This rigorous process can often destroy the original,
therefore extreme caution must be observed in its creation.
The mother mold is similar to a three-dimensional puzzle
with a hard exterior (plaster, fiberglass, etc.) and a
flexible interior (a rubberized or latex material).
Sometimes there are several sections of the mother mold for
one sculpture, depending upon the complexity and size of the
Upon completion of the mother molds, hot wax is poured or
brushed into the negative, thus recreating the entire sculpture
in wax. The wax pieces are joined
together and re-worked until the wax sculpture looks exactly
like the original clay sculpture. If it is a very large
piece, the wax sculpture will be left in refined pieces and
welded together later after the metal casting.
The completed wax is now ready for another mold or
"investment" (made from plaster, sand and vermiculite) which
is coated over the finished wax. When a hard investment
shell covers the wax, the investment is heated and the wax
is burned out. This leaves a negative, again, of the
original sculpture. Into this negative, molten metal is
After the metal is poured, the metal finishing work begins.
This involves cutting, grinding and smoothing the casting.
The next step is the patina, or coloring, of the metal. This
process involves heating the piece with a torch and spraying
specific chemicals, based on the color desired. After the
desired color is attained and while the metal is still hot,
a coat of wax is applied to add luster and to protect the
Usually the last and final step is attaching the sculpture
to a base which involves drilling and bolting.
The entire process is called "Lost Wax Casting" and has
changed very little since the Greeks and other ancient
cultures employed it.