1. Grind the clean, dry surface surrounding the area that needs repair a minimum of 3 inches beyond the damage. If repairing metal, use a grade 36 fibre disc. If repairing fiberglass, use a grade 50 fibre disc.
2. Cut a patch or patches of 3M™ Fiberglass Cloth to extend 2 - 2 1/2 inches beyond the damage. Patch should not extend beyond the area sanded in Step 1.
3. Shake or stir 3M™ Fiberglass Resin.
4. Mix 3M™ Fiberglass Resin and 3M™ Liquid Hardener in a ratio of 12 drops of liquid hardener to one ounce of resin. Use approximately 10 cc’s of hardener to 1 quart of resin (40 cc’s per gallon). Resin will begin to gel in about 30 minutes at temperatures between 75° and 80 ° F. More hardener should be used in cooler temperatures, i.e. the amount of hardener may be doubled at 65° F. (If used below 60° F the resin may not cure.) The amount of hardener may be reduced by half at 90° F. Using 3M™ Fiberglass Resin above 95° F is not recommended.
5. Saturate 3M™ Fiberglass Cloth with mixed resin.
6. Apply saturated cloth to damaged area and work out any air bubbles with a plastic spreader. Additional layers of cloth may be applied as needed. Resin should cure in 30 to 60 minutes, depending on temperature and amount of hardener used.
7. Sand cured resin using a grade 36 disc followed by finer grades to obtain the desired finish. 3M™ Lightweight Body Filler of 3M™ Premium Lightweight body Filler may be applied directly over the cured and sanded resin if desired.
