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TAP Silicone RTV Mold-Making System


This item is a shipping hazard and can only ship via ground delivery within the continental United States.

The TAP Silicone RTV Mold-Making System is a versatile solution for creating virtually any type of mold. Silicone rubber offers low shrinkage, excellent long-term durability, and precise detail reproduction, making it ideal for casting materials like cement, vinyl, wax, plaster, low-melt metals, urethane resins, epoxy resins, and polyester resins.

This system features a two-component, tin-catalyzed, room temperature vulcanizing (RTV) silicone with a Shore A hardness of 25. This means it is flexible, has excellent dimensional stability, and boasts strong elongation and tear resistance. For safety and the best results, follow the directions carefully. The maximum recommended casting temperature is 350ºF, and with a 6-8 hour de-mold time, you can complete two-part molds in just one day.

Side A (Silicone) is an off-white liquid with a medium viscosity of 60,000 cP. As a tin or condensation cure system, it typically avoids cure inhibition. However, some sulfur-containing clays can inhibit curing—though the clay carried by TAP will not affect it. Always test if unsure.

Side B (Catalyst) is blue, making it easy to see when the silicone is fully mixed without streaks. The mixing ratio is 10 parts Side A to 1 part Side B by weight or 9-to-1 by volume. Be sure to shake the catalyst before use.

One pound of silicone yields approximately 12 fluid ounces.

For specific applications, use Thixotropic Additive to thicken the silicone to a peanut butter consistency, ideal for blanket molds and vertical surfaces. To reduce the viscosity of the silicone, use Silicone Thinner.


TAP Video: How to make a simple silicone mold
part 1


TAP Video: How to make a simple silicone mold
part 2


Click here for Mold Making directions made simple.
Click here for TAP Silicone RTV System Product Bulletin.

Click here for Online Moldmaking Guide.
Click here for Choosing A Mold Material guide.
Click here for TAP Silicone RTV label.
Click here for TAP Silicone RTV Catalyst label.