Bondo® All-Purpose Fiberglass Resin is your go-to material for sealing cracks， repairing breaks or filling holes in fiberglass， wood， concrete or metal. Along with cloth tape or matting， this 100% waterproof resin can be used for hundreds of repair projects to include cars， trucks， pools， showers， boats and more. This waterproof， two-part resin includes liquid hardener. Bondo® All-Purpose Fiberglass Resin is your go-to material for sealing cracks， repairing breaks or filling holes in fiberglass， wood， concrete or metal. Along with cloth tape or matting， this 100% waterproof resin can be used for hundreds of repair projects to include cars， trucks， pools， showers， boats and more. This waterproof， two-part resin includes liquid hardener.