When fully cured, it is waterproof and petroleum, chemical, and acid resistant! Surface Applications: Metal, Plastic, PVC, Concrete, Ceramic & Tile, and Fiberglass. Use on: household, automotive, marine, plumbing, crafts, outdoor equipment, agricultural equipment, motorcycles, toys, boats, personal watercraft, inboard and outboard engines, and deck and hull accessories. Repair cracked or damaged metals back to perfection with the Heat Resistance Metal Repair Gel! This should help make your DIY metal repairs easy and fast