Polytek Poly-Optic 1420 Clear Casting Resin

Mix Ratio: 2A:1B Shore Hardness: D85 Pour Time: 15 min. Demold Time: 8 hr. 150F, 30 min. (175F) Maximum Exotherm: 311F (2lb mass) Poly-Optic 1420 Clear Casting Resin is a two-part, liquid polyurethane resin that cures (RTV) to a water-clear, Shore D85 plastic. It cures to a tough, impact and heat-resistant plastic that can be polished and machined and is used extensively in prototyping applications. Heat cure (150F - 180F) is required to achieve optimum physical properties. When cured at room temperature, the result is a brittle, glass-like casting. Vacuum and/or pressure casting techniques are recommended for this product. Cure inhibition can occur when casting this resin in tin-cured silicone rubber molds – use a platinum-cured silicone rubber mold if working with silicones. Notes: Demold time varies with thickness of casting and the amount of Poly-Optic Part X Accelerator added. The thinner the casting, the longer the demold time. Shrinkage in polyurethane resins is caused by gelling while hot then cooling. Parts that cure with minimal temperature rise (exotherm) exhibit minimal shrinkage.