The bronze casting is a prototype procedure, with which liquid bronze, an alloy from copper and tin, into a form is poured, in order to make a desired article of bronze. Typical products were and are among other things bells, Epitaphien, plastics, tools, cannons, mirrors and decoration.
The bronze casting enjoys a long tradition, which goes back in its roots into the Neolithikum. In 4. the pre-Christian millenium has to melt and pour humans begun copper. First proofs for poured copper in Central Europe are crucible finds from the Pfyner culture, Switzerland. Starting from approximately 2200 v. Chr. tin bronze emerges regularly in Central Europe.
The bronze casting is apart from the treatment of cold of the bronze, the most important production process of the Bronzezeit, since it replaces gradually the production of the stone devices. Is of great advantage the reusability of the metal, which can be melted arbitrarily often again.
In the process of mankind history several copying methods developed:
1. Pour in continuous forms
For copper materials continuous forms can be manufactured made of stone and metal. Metal forms are called also molds. Nowadays steel molds are used in the industry. For the handicraft only pouring is into lost forms profitable. The bronze casting plays a role in the modern world primarily for artists, since other materials of the bronze are superior.
2. Pour into lost forms
In the literature the lost-wax process is often equated with the procedure of the lost form. This is technically not correct, since also Sandformen rank among the lost forms, which are destroyed after the casting. With the lost-wax process should be spoken thus rather of the procedure with lost model. Requirements of the plastic material are the flexibility, gas permeability, mechanical maximum stress decay good before the casting and after the casting, in order to call only the most important. The casting takes place usually into cold forms, which must be absolutely burned first drying. Here is to be also removed on it to respected all chemically bound crystal water.
The following article describes the production of a wax positive with the help of a so-called form of piece of gypsum. The wax positive is needed for the production of a form with the lost-wax process. Since a relatively new development are here a traditional way described the silicone rubber masses, with which wax models can be manufactured also without silicone rubber. A piece form consists of individual pieces, which cast parts of the model in such a manner that no Hinterschneidungen develops, which would make a removing of the pieces impossible. After all pieces of gypsum manufactured, and the piece form is finished, to open the pieces of gypsum successively again removed around the gypsum positive. The pieces of gypsum are and added afterwards together. The developed cavity is expenditure-painted in the following and/or swivelled with liquid wax. After the wax cooled off can the individual pieces of gypsum be removed and the wax model can be taken. From more or less large number of pieces of gypsum on the wax numerous seams resulted, which must be revised before manufacturing the mold.