3M Bondo 422 Fiberglass Resin Repair Can Kit - 29 Oz.

This Bondo repair kit is a do-it-yourself solution for easy and effective auto body repair. Users can repair cracked, broken or rusted automobile body components quickly, easily and at a fraction of the cost versus part or panel replacement. The kit includes resin and hardener for a permanent, 100% waterproof seal that hardens in as little as two hours and is compatible with any paint. Bondo repair set lets users do it themselves for easy, cost-effective, shop quality auto body repair. This kit includes cloth, resin and hardener for straightforward application over cracks and metal rust-outs.

The resin bonds to metals and plastics, and hardens to a sandable surface in less than two hours.
Warning: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm.