Sculpture Process

I start by sketching the subject that I am trying to visualize. This is a very loose gesture. What I am looking for is feeling, motion and mass to fit the composition I have in mind.

When this phase is complete I decide how large it should be. Then the armature is assembled that will be the structural support for the sculpture. I generally build armatures out of plumbing parts and wire of various material and gages. Wax is then applied to the armature, building the form from the inside out. After I am satisfied with the form, I start to define the shapes and relationships within the sculpture. The sculpture is then finished and made ready for casting.

The casting process takes the sculpture through a series of positive and negative shapes to arrive at the finished bronze. The casting process begins by making a master mold from rubber and fiberglass or plaster.

The original sculpture is cut into pieces that can be easily molded. The pieces are then laid out on a table and shimmed or embedded half way in clay. Rubber is applied to the sculpture followed by fiberglass or plaster. The sculpture is flipped over and the process repeated to complete the rubber mold.

The original is removed from the mold and the sculpture exists as negative shape within the mold. Liquid wax is painted or poured into the rubber mold to create a hollow wax of the original form, which can then be reassembled with wax parts from the other molds. Now the sculpture is a positive shape made of hard wax.

The sculpture is then attached to a wax cup by a series of wax gates that become the delivery system for the molten bronze. This entire wax assembly is dipped in ceramic slurry and coated with silica sand several times to create the ceramic shell that becomes the mold into which the bronze is poured. After the shell is thick enough and dried thoroughly it is placed into a burnout furnace to remove the wax and to fire the ceramic shell.

The sculpture now exists as a negative shape inside the burned out shell. Bronze is melted and poured into the hot ceramic shell. The sculpture is now a positive shape cast in bronze.

The ceramic shell is chipped off and the gates are cut away from the sculpture, which is reassembled and chased till the final bronze looks exactly like the original wax or clay model.

The finish on the bronze is called a patina. The patina process involves chemical alteration to the surface of the bronze. This is accomplished by applying chemical compounds in solution to the surface of the metal with heat to cause the bronze to turn various colors as determined by the composition and concentration of the solutions as well as the amount of heat with which it is applied. The bronze is then hot waxed, mounted on its base and is ready to be shipped.