Environmental Technology 33710 1-Pound Kit Casting' Craft Easymold Silicone Putty Environmental-Castin'Craft EasyMold Silicone Putty Heat range is up to 400 degree F. It is self releasing with no mold release agent required for most applications It is self releasing with no mold release agent required for most applications Easy to use, 3-minute working time, 25-minute cure Ideal for small molds, excellent detail from original Strong, flexible, reusable molds High Heat range, up to 400-Degree F Self releasing, no mold release agent required for most applications.