Sandra BÉRUBÉ

Sculptor

Bronze Casting, Blacksmithing & Installations

Bronze Casting

Bronze is considered one of the most noble materials in sculpture. Bronze casting is an elaborate sculpting technique based on the lost wax process. 

The first step is creating the sculpture in clay. From that, a silicone mold is made and used to pour a wax replica of the sculpture, which will be reworked and often cut into parts in preparation for the casting. The next step is adding pour spouts and vents to the wax to allow the bronze to flow freely and allow the air to escape. Then, several coats of silica sands around the wax added over the course of several days become a solid ceramic shell mold. The burnout step melts the wax out, leaving the mold with an empty negative space of the initial sculpture.

On the pour day, the temperature of the room rises as both the bronze ingots and the molds in the kiln are heated until they start glowing. The molten bronze, a beautiful, highly reflective glowing orange liquid, is carefully poured into the pre-heated shell. Once hardened, the ceramic shell is broken by hand with chisels and a hammer, a very physical yet delicate operation, as impact precision is crucial to avoid damaging the bronze surface. All the vents and spouts need to be cut away to free the art, which needs to be resurfaced and reassembled back together by welding to recreate the original sculpture. The finishing consists of applying heat patinas, which gives rich colors to the bronze, before sealing it with natural protective wax.

The hands-on creation of each bronze sculpture results in unique art pieces, with their own variation in detail and color.