Sculpture Techniques: Bronze Casting
Bronze is an alloy of copper and tin, and often also contains lead or zinc. It is strong and durable but can also capture the fine, complex detail within a casting mould. The term 'bronze' is often used for other metals, including brass, which is an alloy of copper and zinc.
Bronze has been used in Europe since antiquity to produce tools, weapons, sculpture and decorative works. This continued throughout the medieval period. In the 15th century there was then a deliberate revival of the forms and techniques of ancient Greece and Rome.
There are two basic methods of casting a bronze. Sand casting is a simple technique that uses moulds made of compact, fine sand. Lost-wax casting is a complex process using wax models.
In the 'direct' method, the original wax model is used and therefore destroyed. In the 'indirect' method, plaster moulds are taken from the original wax. These can then be reused many times.