Two Part polyurethane resin in coimbatore Then there are polyurethane casting resins. They are fast setting and our product offerings do not need a respirator as they are very low in odor emission. These polyurethane casting resin products are two-part, 1-to-1 mix ratio formulas that set from 5 to 20-minutes. The two varieties offered here are opaque and a water clear resin. The opaque resins set to an ivory color in approximately 5-8 minutes. The clear casting resins require more setting time up to about 25-minutes. The advanced formula clear resins set with fewer air bubbles than most available formulas. We even offer a unique polyesher resin formula that will expand (point up) your castings up to 160% However, no water clear polyurethane casting resin is completely bubble free. Therefore, the use of a pressure pot is recommended to perfect the casting without bubbles. The advantage of polyurethane resins over polyester resins is that these formulas are very low in odor compared to carcinogenic producing smells of polyester resins.