A pourable mold rubber that vulcanizes at room temperature without pressure, Contenti RTV Silicone is a 0% shrinkage, condensation (tin) cure rubber that cures in 16 hours. While this rubber can render a wax pattern of exceptional detail, it can also withstand the casting temperature of most tin alloys, making it an ideal medium for prototype casting. A two-part mold can be made by pouring mold halves on successive days. When you need to reproduce a pattern that cannot withstand the heat and stress of vulcanization, RTV Silicone is the ideal mold rubber. Furnished in 1 lb. cans or 45 lb. pails. Both weights include the activator, which is packaged separately. 28 durometer.