In investment casting, the process of turning slurry-covered wax patterns into hardened molds is called investment casting firing. The patterns are placed in high-temperature ovens that heat to approximately 1,800º F. This is hot enough to solidify and harden the ceramic and melt out the wax patterns and sprues. This is why investment casting is sometimes referred to as the “lost wax process.” When fully hardened, the ceramic molds can hold molten alloys of thousands of degrees until it cools on sand beds into finished castings.
