These polyurethane mold rubbers span the range of very soft (A~20) to very firm (D~45) rubbers which, when mixed as supplied, can be used to create a multitude of poured molds and flexible parts. These liquid rubbers are excellent choices for making molds for casting concrete, plaster, wax as well as for limited resin and foam casting applications. The Poly 74-Series rubbers are soft to mid-range hardness rubbers (A~20-55) and can also be thickened with fumed silica or Poly Fiber II to create brushed molds. Poly 75 & 77-Series rubbers are mid-range to firm rubbers (A~60-90) and Poly 81-Series systems are even firmer yet (A~90 to D~45). Poly 72-40 can be thickened with a liquid thickener for brush-on mold applications. GlassRub is a clear specialty rubber used for cut molds where clarity is important or for casting clear art objects & decor.
Watch a polyurethane mold being poured