Poly 74-41 is a 1A:1B mix ratio polyurethane mold rubber that cures to a Shore A~40 hardness. The easy 1:1 mix ratio makes Poly 74-41 an alternative to Poly 74-40 which is a 2A:1B mix system. It offers a long working time, low mixed viscosity and an overnight cure to produce a tough polyurethane mold that can be used to cast concrete, wax, plaster as well as resins with appropriate release. Poly 74-41 can be poured as supplied or can be mixed with Poly Fiber II thickener to make the rubber any brushable consistency. This rubber can also be accelerated for a rapid demold at room temperature using Poly 74/75 Part X Accelerator.