Poly 74 & 75 Series Polyurethane Mold Rubber Kits offer a versatile 1A:1B mixing ratio with a range of shore hardness options, from 20 (softer) to 70 (harder). These polyurethane liquid rubbers are specifically formulated for crafting high-performance rubber molds, suitable for various casting materials such as plaster (ideal for millwork and home décor), wax (including candles and lost wax varieties), concrete, GFRC, GRG, and a variety of resins (including polyurethane, polyester, and epoxy when used with the appropriate release agents).
These polyurethane rubber molds can be conveniently poured as is, or you can choose to apply them by brushing on the material mixed with PolyFiberII thickener or fumed silica. The Polyurethane liquid rubber is a cost-effective, multi-purpose mold material, known for its exceptional mold life, durability, and consistent performance when subjected to repeated casting. Among the various options, Poly 74-45 is particularly well-regarded for casting decorative architectural concrete panels and related accessories.
|Pour Time||20 min.||25-30 min.||30 min.||10 min.||40 min.|
|Demold Time||16 hr.||16 hr.||16 hr.||16 hr.||16 hr.|
|Tensile Strength (psi)||220||281||408||545||938|
Determine total volume of the model:(L” x W” x H”) = ________ in³
Subtract the volume of the model from the volume of the mold box:_________in³ - ________in³ =____________in³(this is the total volume of mold rubber needed)
Divide the result by 27 in³/lb (this is the specific volume of the mold rubber) to determine the total lbs of liquid rubber needed
The simplified formula for this is:_________in³ ÷ 27 in³/lb. =_________ lb. of Poly rubber