Smooth-Cast 385 is a mineral filled urethane casting resin that is very hard and durable. When Parts A and B are mixed in proper proportion (1A:5B by weight), the material cures at room temperature with virtually no shrinkage. Smooth-Cast 385 has high compressive and flexural strength. Fully cured castings are tough, machinable and paintable. Color effects are possible by adding pigment dispersions. They resist moisture and mild solvents. Smooth-Cast® 385 is ideal for making industrial production parts, foundry patterns, vacuum forming molds, and some ceramic applications.Smooth-Cast 385 - 2 hour demold time