NovaSil #737 is a strong, flexible, tin-based, two-part silicone rubber used for mold making. It is designed for casting polyester, urethane and epoxy parts. It is also used for embossing, texturing, pad printing, stamp pads and electrical insulation.
The NovaSil #737 offers the following advantages over other RTV silicones:
Extremely high tear strength
- Low shrinkage
- Variable cure rate
- Excellent chemical resistance
- Long shelf life
- Low viscosity
- Insensitive to inhibition
- Good dielectric properties
NovaSil #737 is recommended for molds containing deep undercuts due to its flexibility and strength for easy part removal. Its low viscosity ensures easy mixing and pouring in addition to reducing air entrapment. The NovaSil #737 is dimensionally stable and is resistant to various casting chemicals such as urethanes, polyesters and epoxies. Custom pot lives and cure times can be achieved with the use of different catalysts.
Mix 10 parts by weight of Part A (resin) with 1 part by weight of Part B (catalyst). Mix thoroughly in a clean container by hand or by mechanical mixer until you have a uniform color. Be sure to scrape the sides and bottom of the container. Optional: If a vacuum chamber is to be used, immediately place mixed silicone rubber into chamber and pull 29 inches of mercury. Material will rise, then collapse. Continue the vacuum for another minute and stop. Carefully pour the catalyzed silicone rubber into the mold box or onto the pattern at its lowest point. Allow 16 - 24 hours for a full cure.