Firm-durometer tin-cure RTV-2 silicone for foam casting

General Information

GI-1040 is a high tear strength, tin-catalyzed RTV-2 silicone rubber, which was designed for casting polyurethane foam parts. GI-1040 has a Shore A Hardness of 40, giving it the ability to resist distortion due to the expansion of the foam. GI-1040 is not sensitive to inhibition, meaning it will cure at room temperature over virtually any surface. It is easy to mix and de-air, and will cure with only a slight degree of shrinkage. The speed at which the rubber hardens can be accelerated with special activators. GI-1040 is also excellent for casting solid urethanes, polyesters and epoxies where a free standing mold that can maintain a straight edge is required.

Typical Properties

Uncatalyzed Compound

Color

Base:Off-whiteActivator:Blue

Viscosity

Base:90,000–110,000cpsActivator:300–400cps

Mixing Ratio

By weight:100:10By volume:100:11.3

Mixed Viscosity

50,000–65,000cps

Working Time

1.5–2.5hours

Cure Time

16–18hours

Shelf Life

6months

Vulcanized (Cured) Properties

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

Shore A Hardness

One day:307 days:40

±4 durometer

Tear Resistance

100 ± 15ppiASTM D624

Tensile Strength

525 ± 25psiASTM D412

Elongation

225 ± 25%ASTM D412

Service Temperature

-60 to 350°F

Shrinkage

0.20%

Specific Gravity

1.10

Coverage

25.2in³ / lb