3M Bondo 422 Fiberglass Resin Repair Kit Bondo Fiberglass Repair Kit 420 has everything needed for the Do-It-Yourselfer Includes easy how-to directions, fiberglass resin, and liquid hardener Includes other necessary items like plastic spreader, fiberglass cloth. Non-shrinking polyester resin bonds to metals and plastics Kit includes all materials for easy application Hardens quickly for fast repairs Includes directions for easy, trouble-free use Do-it-yourself auto body repair at a fraction of the time and cost