Chemical-resistant tin-cure RTV-2 mold making silicone

General Information

GI-491 is a high tear, high tensile strength, tin catalyzed silicone designed to be used when casting polyurethane foam, polyester and epoxy parts. GI-491 is useful for applications where a flexible rubber with increased chemical resistance is required. When catalyzed with one of our library life extending catalysts (see supplemental products) and stored correctly, a longer life of the cured mold should be expected. Its high tear strength, elongation and tensile strength make it an excellent choice for any mold making application. It is also resistant to inhibition by most common mold making substrates, eliminating the need to use mold sealers.

Typical Properties

Uncatalyzed Compound

Color

Base:Off WhiteActivator:Blue

Viscosity

Base:50,000–70,000cpsActivator:350–500cps

Mixing Ratio

By weight:100:10By volume:100:11.1

Mixed Viscosity

30,000–45,000cps

Working Time

1.0–1.5hours

Cure Time

16–18hours

Shelf Life

6months

Vulcanized (Cured) Properties

Measured at 7 days, 70°F / 50% relative humidity

Shore A Hardness

One day:207 days:26

±4 durometer

Tear Resistance

120 ± 10ppiASTM D624

Tensile Strength

525 ± 25psiASTM D412

Elongation

300 ± 25%ASTM D412

Service Temperature

-60 to 350°F

Shrinkage

0.10%

Specific Gravity

1.09

Coverage

25.2in³ / lb