3M™ Fiberglass Resin is designed to be used with 3M™ Fiberglass Cloth, part number 05838 and/or 3M™ Fiberglass Mat, part number 05833 to patch holes in metal, and cracks, tears, punctures and splits in fiberglass panels. Waterproof when cured. 3M™ Liquid Hardener, part number 05836, included. Thick formulation resists sags and runs.