Pour tough, flexible parts and molds with Urethane Casting Resin Shore A. Available in two hardness variations, 40 Shore A and 60 Shore A. These urethane casting resins make it easy to create softer more resilient parts and tooling. These urethane casting resins have been designed specifically for the pouring of prototype and production parts. They can also be used to create fast flexible molds with some undercut or negative draft. While silicone can be used to create more flexible and lower cost molds, Urethane offers superior tear strength and offer 3-4 times the mold life. Shore A resins can accept pigments to achieve opaque colors in finished castings. These Urethanes are used in many common mainstream products, but are especially popular in automotive applications. When mixed thoroughly, pour the urethane slowly to aid the release of any air bubbles. When using Urethane Casting Resin Shore A kits, avoid water and all types of moisture contamination. Do not use any urethane kit with PVA Release Film, and do not mix with wooden mixing sticks or in paper mixing containers. #2333 Plastic Paint Stirrers for Urethanes are recommended. To ensure a proper release from a mold, use at least four layers of #4121 Non-Silicone High Temp Paste Wax. Urethane Casting Resins with Shore A hardness can completely cure at room temperature, but can also be heat cured up to 150°F for faster production rates. #3340 Urethane Casting Resin 40 Shore A Mix Ratio (by weight) – 100:75 Color – Light Amber Working Time, 4 fl. Oz. mass @ 77°F – 25 minutes Demold Time (75°F) – 2.5 - 3 hrs (150°F Cure) – 30-40 minutes #3360 Urethane Casting Resin 60 Shore A Mix Ratio (by weight) – 100:55 Color – Light Amber Working Time, 4 fl. Oz. mass @ 77°F – 15 minutes Demold Time (75°F) – 2 – 2.5 hrs (150°F Cure) – 30-40 minutes
