What is the process of bronze casting?
Bronze casting is actually a multi-step process, involving moldmaking, welding and patinization*. In short, the original sculpture is made, in wax or clay usually. If made in clay a mold is made so a wax casting may be made. Once in wax another mold is made, one method is called ceramic shell. The wax is dipped in a wet silicia mixture, then dipped in a fine sand mixture, a series of dips are made with different grades of sand until a shell is made to cover the wax. This is then heated to harden the shell and expel the wax, hence the term “lost wax method.” The shells are then heated again and molten bronze is poured into them, usually around 2000 degrees farenheit. Once cooled the shells are broken off and the piece is ready for some metal work. In order for the bronze to flow sprues, vents and pour cups were attached, that now need to removed. Also the piece may have been too large or complicated to pour in one shell. This involves removal of the sprues, vents and cups and recontruct
