Polygel 50 mold rubbers consist of two liquids, Part A and Part B, which after mixing one to one by weight or volume, immediately gel to a brushable or trowellable consistency, then cure overnight at room temperature to a flexible, tough RTV(room temperature vulcanizing) rubber. They are ideal for molds built up with a brush, spatula or spray.

Polygel 50 yields a thicker mix and cures to a tougher 50 Shore A hardness. It is an excellent adhesive for bonding Poly Urethane rubbers to many materials. New, Polygel® Spray 50 consists of a blue Part A and a yellow Part B which yield a green mix.

As the liquid components of Polygel are stirred together, the mix changes color and thickens to a buttery non-sag paste with a working time of about twenty minutes. A mold can be built up in two or three coats, each applied about one hour apart, so the mold can be finished in several hours. Sprayed molds can be completed in one application. The rubber will cure overnight at room temperature to a tough skin mold, which can be reinforced with fabric, if desired.

An easy-to-use brush-on rubber, Brush-On 50 provides ample working time for careful application. With a creamy consistency, it also brushes easily onto vertical surfaces. It cures with negligible shrinkage to a durable rubber that will stand up to repeated casting of abrasive materials. Especially useful for casting concrete.

Smooth-On’s Brush-On Series of mold rubbers are extremely versatile and are famous for their abrasion resistance and high tear strength. They have the convenience of a one-to-one mix ratio and are easy to mix and apply with a brush or spatula. Brush-On 50 can be painted onto vertical surfaces without sagging and will cure with negligible shrinkage to durable rubbers that perform and last in production. Each will capture exact detail from any original model. Brush-On 40 is the softest of the series and offers the most flexibility and is used for models with deep undercuts.
Brush-On 40 can be inverted and used to make glove molds. As an example, you can apply two coats of Brush-On 40 and back it up with two coats of Brush-On 50 or 60. All three rubbers are suitable for reproducing sculpture, architectural restoration and production casting of concrete.