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 Viscosity(cps)Mixing Ratio (B/A) Viscosity(cps)Working Time Cure Time
Shelf Life
Base: Off-white or Trans
Base: 90,000-110,000 By weight: 100 / 10 Mixed: 50,000-65,000 1.5 to 2.5 hours
16-18 hours for demold 6 months
Activator: Blue Activator or Trans: 300-400
By volume: 100 / 11.3
Vulcanized (cured) Properties (7 days @ 70° F / 50% relative humidity)
Shore A Hardness (±4)
Tear Resistance (ASTM D624)Tensile Strength (ASTM D412)Elongation (ASTM D412)Service Temperature (° F)Shrinkage
Specific Gravity
Coverage (in3 / lb)
One day: 30 100 ± 15 ppi 525 ± 25 psi 225 ± 25 % -60 to 350 0.20 %
1.10 25.2
7 Days: 40
