Smooth-Cast ONYX® is a mercury-free urethane resin that cures quickly at room temperature to a deep black, solid plastic. ONYX® offers the convenience of a 1A:1B by volume mix ratio and has a very low viscosity, so it is easy to mix and pour. ONYX® has an ultimate shore hardness of 80D and offers higher physical properties and higher heat resistance vs. other general purpose resins.
Applications include reproducing sculpture, making prototypes and potting / encapsulation. Because ONYX® is a fast curing resin and becomes hard quickly, it is also great for doing fast cold cast bronze, brass, copper, nickel/silver, etc.