Video: Foundry artists at Birmingham Sculpture Foundry pouring bronze into ceramic shells.

Cindy Free creates her sculptures following the “lost wax casting” tradition that is a 6,000 year old process. The sculpture is first formed in clay while supported on an armature. Once completed, the artist makes a rubber mold of the sculpture which is then surrounded by a hard shell called the “mother mold”. Next, a special wax is poured into the hollow rubber mold – thus, creating a wax positive of the sculpture. Straw-like structures called “sprues” are connected to the wax positive creating pathways for bronze and air to flow. The wax positive is then dipped many times into a ceramic slurry to create a thick ceramic shell. When the ceramic shell is hardened by firing it, the wax melts out. This is why the process is called the “lost wax method”. Molten hot bronze is poured into the ceramic shell. Once cooled, the ceramic shell and sprues are detached and then any imperfections that arose during the casting are removed in a process called “chasing”. Finally, the artist adds patina and polishes the piece. The resulting work of art is ready to be enjoyed for centuries.