3M 20124 All Purpose Fiberglass Resin, 1 Gallon Bondo All-Purpose Fiberglass Resin is 100% waterproof For interior and exterior repairs Product cures in 2 hours, resulting in a non-shrinking and durable repair Compatible with all paints and gel coats and includes Bondo Fiberglass Resin Liquid Hardener Designed for tub, shower, sink, pool, hot tub, boat repair, and more Use for small to very large repairs to any fiberglass, metal, wood or masonry surface. 1 Gallon Can