R-2157 Base & Activator is a Platinum Cured (Addition Cure), two-component, room temperature curing (RTV) silicone rubbers designed for general mold making. This systems is low in viscosity and exhibits high Physical profiles. Use molds to cast polyester, urethane, epoxy, low melt metal (600F), thermoplastics (Polyvinyl), wax, soap, plaster, and any material where a release free casting is required.