Jewelry Making - Casting

Casting is an ancient method of jewelry making, but still widely used today. Low wax casting dates back to at least 1500BC, when the Egyptians used it. For awhile this method disappeared, but in recent years it has become the most widely used manufacturing process.Low wax casting involves a series of steps, as follow.

1. A model(jewelry piece) is made in metal from an orginal design. Sometimes the model is a piece which has already been cast. (Often the first step in lost wax casting is to carve a model in wax. The rubber molding process, described in steps 1 to 3, is relatively new compared to the modeling of wax by hand carving.)
2. A rubber mold of the metal model is made. The model is placed in a rectangular frame, rubber is packed around it, the rubber is heated so it flows around the model and is vulcanized into a solid block.
3. A wax copy of the model is madeby injecting wax into the mold through a hole. An original wax model may be carved or sculpted instead. It’s usualy faster to carve a wax model than to make a metal model.
4. The wax model are attaced to a base either in the form of a tree or a donut. The tree may be formed with several wax models all made from the same mold or with different-style models.
5. The wax tree or donut is covered with a material like plaster of paris, called investment. This is allowed to harden.
6. The plaster mold is heated. The wax melts and pours our of a hole in the base. A hollow plaster mold is left.
7. Molten gold or platinum is thrust into the plaster mold by centrifugal force or vacuum. The open spaces left by the melted wax are filled with the metal. The gold or platinum is alowed to solidity.
8. The hot plaster mold is plunged into water. The sudden change of temperature makes the plaster shatter, leaving metal copies of the wax models. These are cleaned and polished.