PolyCoatPolyCoat is a sealer and semi permanent release that can be sprayed or wiped onto polyurethane rubbers to give them a thin silicone coating that reacts and bonds to the underlying polyurethane surface. This thin coating can do amazing things. For Mold Making: Apply PolyCoat to porous (may require multiple coats depending on porosity) or non porous models when making polyurethane and platinum cured silicone rubber molds (not recommended for use with