3M Fiberglass Resin Repair Kit — 0.9 Quart DIY kit for cars & boats, waterproof sandable finish

3M Bondo Fiberglass Resin Repair Kit (00422) is a complete 0.9 quart DIY kit for repairing holes, cracks and damaged surfaces on cars, boats and more with a waterproof, sandable finish.

This kit supplies everything needed to restore fiberglass, metal, wood and concrete panels without replacing entire parts. The package contains resin and liquid hardener formulated to bond and seal; included tools like cloth, spreader and mixing tray simplify application for hobbyists and professionals alike. Cures quickly and sands smooth in about two hours, letting you move to priming and paint sooner.

What damage can this kit repair?

The Bondo Fiberglass Resin Repair Kit is built to handle punctures, cracks, delamination and larger holes on automobile body panels, boat hulls, fiberglass trim and structural patches. It creates a waterproof bond that restores strength and prevents moisture intrusion.

• Patching holes and gouges in fiberglass and gelcoat
• Filling rusted or corroded metal patches before surface finish
• Repairing wood or concrete spots where a waterproof seal is needed
• Laminating layers with the included fiberglass cloth for structural support

How long does the repair take from mix to sandable?

Set and cure times depend on temperature and amount of hardener used, but typical repairs reach a sandable state in about two hours under normal shop conditions. The fast cure helps you move through builds quickly while allowing adequate working time for shaping and wetting fiberglass cloth.

• Mix resin and hardener per included instructions for predictable cure
• Partial cure in roughly 20–30 minutes for tack-free handling
• Sandable, stable surface in about two hours at room temperature
• Full mechanical strength continues to develop after initial cure

What tools and materials are included and what else will I need?

The kit arrives with resin, liquid hardener, a plastic spreader, fiberglass cloth, mixing stick and mixing tray so you can begin most repairs immediately. For best results you may want common workshop extras for surface prep and finishing.

• Included: resin, hardener, spreader, cloth, mixing stick, tray
• Recommended: sandpaper, body filler or primer, protective gloves, respirator
• Optional: fiberglass mat for large area reinforcement, power sander for finish work
• Paint compatibility: sands smooth and accepts most automotive primers and paints

How durable and waterproof are the finished repairs?

When mixed and applied correctly, the cured resin creates a durable, waterproof seal suitable for exterior automotive and marine use. It restores structural integrity where cloth is laminated and provides a base that accepts subsequent finishing coats.

• 100% waterproof when fully cured and properly finished
• Strong adhesion to fiberglass, many metals, wood and concrete
• Resists moisture intrusion that can cause further damage
• Sandable surface that accepts primer and paint for lasting appearance

Who is this for: The 3M Bondo Fiberglass Resin Repair Kit (00422) is designed for DIYers, hobbyists, body shop technicians and boat owners who need a ready-to-use repair system for small to medium fiberglass and mixed-material damage. If you want a portable, all-in-one kit that offers fast curing, waterproof sealing and a sandable finish to prepare for paint, this kit supplies the essential materials and basic tools to complete those projects without replacing entire panels.