The creation of bronze, an alloy of copper and tin, often with a small amount of lead, changed the landscape of humanity around 2500 BC. The metal was first used for making tools and weapons. It soon became valued for its aesthetic beauty and myriad objects from bowls to sculpture were cast or hammered from sheets of bronze. Thanks to new technology of the past 30 years there is a renaissance of bronze casting today. Kimber is an expert at the ancient art of transforming a clay sculpture into a work of bronze, which requires skills in several areas.

From idea to wire

The first step is the assembly of the armature. Made of black pipe and steel rebar, it will support a clay model of the future bronze.

From wire to clay

When the wire form is complete, clay is applied. It will be scraped and smoothed to create a model of the finished form.

Since this piece will be cast in sections, aluminum shims are attached to mark section boundaries.

Layers of liquid rubber and plastic are applied. They harden to form a thick shell around the clay. The sculpture is cut into pieces.

The mold

The mold is pried apart along the shim lines, and the inner clay and wire is removed.

The mold is reassembled, was is heated to melting, and poured into the mold to create a hollow wax piece with walls about 1/8th inch thick.

Final detailing

The wax cools and the mold is removed. Each wax piece is carefully detailed, as whatever is in wax will be recreated in bronze.

Attaching the gates

Gates are attached to each piece. They will allow the bronze to flow to all parts.

Ceramic shell

Each piece is dipped in liquid ceramic shell and then in various grades of silica sand. finished form. Each piece will be coated up to 10 times to create a shell that is capable of withstanding the heat and pressure of molten bronze.

Flashout kiln

The shells are placed in a flashout kiln, and the wax is melted away.

Preheat kiln

They are checked for cracks, and then put in a preheat kiln and heated to about 1600-1700 degrees Fahrenheit.

The furnace

Ingots of Everdure bronze are placed in a furnace and brought to 2000 degrees. The molten bronze is poured into a heated crucible.

The pour

Each mold is carefully filled will molten bronze, and left to cool.

Removing the shell

When cool, the shell is knocked off. The gates are cut off, and each piece is sandblasted to remove any extraneous ceramic.

Preparation for welding

Edges are ground to make a close fit and a channel for the weld.

The pieces are welded together. Plumbing pipes are installed in this piece, as it will become a fountain.

Welding and grinding

Each seam must be welded and ground so that no seam lines are apparent in the finished piece.

Polishing

The piece is polished throughout, using various grades of abrasives.

Patina

Finally, a patina is applied. It is a chemical mix, which when heated, alters the surface of the bronze.

The patina determines the final color of the piece. Since this is a fountain which will reside in a pond, a blue-green chemical mix was selected.

A cement base is prepared, and the sculpture is bolted to it. The water supply is hooked up, and the fountain is ready for action.