Bronze bars are cast in much the same way that a sculpture made of bronze is created. The bronze casting method to use depends upon what you plan to do with the finished product. Finished bars that will be put into regular use need to be strong and durable, while bars that will not be handled regularly do not need to be as tough.
Cold Cast Bronze
Bronze bars made from the cold cast method can be produced more quickly and efficiently than the hot cast, but they are also less durable. These bronze bars will also be less resistant to temperature extremes and high humidity levels. In the cold cast method, a mixture of resin and bronze powder is put into the bar mold. The bars should be cleaned every six months with a soft cloth and then placed under direct sunlight for two to four hours.
Hot Cast Bronze
The hot casting method is best if you need a finished product that is strong. First, a mold is filled with wax, which will be shaped with tunnels for the entrance of the molten bronze. Next, the molten bronze is poured into the mold. The wax helps to ensure that the bars are formed evenly and without any fissures or air bubbles. A long curing period is needed for the hot casting method, as the wax insulates the heat and slows down the solidification of the bronze.