Gallon Fiberglass Resin 58020 Fiberglass Resin. Use with USC Fiberglass Mat or Fiberglass Cloth to rebuild and repair cracks, holes, splits, tears and other damage in fiberglass. Ideal for custom molding. Thicker viscosity for less running and sagging Better wetting and coating of fibers Fast curing. Tack free Waterproof and impact resistant Liquid hardener included COLOR: Opaque amber (as packaged) MIX: Mix 14 drops of supplied hardener to 1 oz. of Fiberglass Resin. SUBSTRATE: Fiberglass. Metal. Wood. Gel coat (polyester or epoxy) SUGGESTED USE: Use for fiberglass repair and custom molding. TOP COAT: Primer surfacer Product Code Size/Description Wt/Case 58020 Gallon 42 lbs. U.S. Chemical & Plastic 58020  Gallon Fiberglass Resin