Cabosil is an excellent filler for urethanes and silicones. Use this product to make many rubbers brushable.

Warning: Fumed Silica… always wear a respirator!!!

Cabosil–fumed-silica thickening agentis primarily used with liquidurethane and silicone rubbers for brushon moldmaking applications.Cabosilis added in small amounts to the mixed rubber until the desired viscosity is achieved. It can also be added toliquid urethane resinsto create casting effects and to thicken the material for trowelable casting applications.

Guarding Against Moisture– All powder fillers will absorb atmospheric moisture over time which will react with urethane materials. If you experience bubbling or foaming in your resin/filler mix, your filler probably contains moisture.

Remedy:Line a cookie sheet with foil and spread filler evenly over the cookie sheet at 3/8-1/2 thickness (0.95 cm-1.25 cm). Place in an oven on warm setting (100F / 38C) and bake for two hours. Remove cookie sheet from oven (dont burn yourself!) and redistribute filler on cookie sheet. Place back in oven and bake for two hours. Let filler cool to room temperature before mixing with urethane materials.

Storage– To prevent moisture absorption, use filler as quickly as possible after purchasing. Decant filler from container and replace lid immediately…do not leave container opened for more than a minute. If filler will be stored for prolonged periods, obtain dessicant pouches at your local hobby/arts and crafts store and place one or two dessicant pouches in container. Replace used dessicant pouches every other time you open container. Make sure container lid is secure before storing.