The next three steps of investment casting are dipping and coating, de-waxing and firing, and casting. The finished sprue is coated with multiple layers of ceramic and stucco. This can be done by hand or robotically. The result is a hard shell around the wax on the sprue, creating the casting molds. Next, the sprue is flash fired to melt and remove the wax, leaving only the molds, which are heated to 1,800 degrees to prepare it for receiving molten alloys. Next, the molds are placed on a sand bed and are filled with molten alloy that can be as hot as 3,000 degrees or more. After pouring is complete, the molds and metal are allowed to cool.
