Fiberglass Repair Kit - Complete DIY Kit with Resin, Cloth & Mat
Fiberglass Repair Kit - Complete DIY Kit with Resin, Cloth & Mat
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SKU:SK-FRK001
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Everything you need to make a real structural fiberglass repair, in one box. This is the same materials list we sell to boatyards every week, portioned for a DIY repair: real laminating resin, real glass, and every tool the job needs. No searching for a missing hardener or one clean brush mid layup.
What is in the kit:
- 1 Quart Silmar 249 clear polyester laminating resin
- MEKP hardener (catalyzes the full quart)
- 1 yard x 38" of 6oz woven fiberglass cloth
- 1 yard x 38" of 1.5oz chopped strand mat
- 1 Quart fumed silica thickener, for filling gouges and tight fillets
- Prep & Fair wet/dry sandpaper 6-pack (120 / 150 / 180 / 240 / 320 / 400)
- 2 chip brushes, 4 mixing cups, 4 mixing sticks, plastic spreader, nitrile gloves
What it repairs: cracked or holed fiberglass on boats, RV and camper sidewalls, kayaks and canoes with composite hulls, tubs, tanks, fenders, and molds. Grind the damage back, laminate mat then cloth, fair it smooth, and finish sand with the included grit ladder.
Enough material for several small repairs or one large one, roughly a square yard of two-layer laminate. Not for polyethylene plastic (rotomolded) hulls, which resin does not bond to.
Specifications
Includes
Features
Resin Calculator
How to use this kit
Structural fiberglass repair with resin, cloth and mat. Every kit ships with this same sheet printed and in the box.
What is in the kit
- 1 qt Silmar 249 polyester laminating resinthe structural resin for every glass layer
- 1 MEKP hardener, 2 ozcatalyzes the full quart
- 1 yd 6 oz woven fiberglass cloth, 38 in widestrength and a smooth outer layer
- 1 yd 1.5 oz chopped strand mat, 38 in widebulk and the first layer against the repair
- 1 qt Fumed silica thickenerstir into resin to make fairing putty
- 6 Prep & Fair wet/dry sandpaper120 / 150 / 180 / 240 / 320 / 400 grit
- 2 / 4 / 4 Chip brushes, mixing cups, mixing sticks
- 1 / 1 pr Plastic spreader, nitrile gloves
You supply: acetone, an angle grinder or 80 grit block, a dust mask or respirator, masking tape and plastic sheet.
Mixing MEKP (1.5 percent)
| 4 oz mix | 1.8 mL MEKP (about 1/3 tsp) |
| 8 oz mix | 3.6 mL MEKP (about 3/4 tsp) |
| Full quart | 14 mL MEKP (about 3 tsp) |
That is 1.5 percent for 65 to 85 F. Above 85 F drop to 1 percent; at 60 to 65 F go to 2 percent. Quick field rule: 10 drops per ounce.
Working time is 15 to 20 minutes. Mix small batches you can use right away.
The job, start to finish
Grind it back
Wash with soapy water, dry, then wipe with acetone. Grind the damage back to solid glass and dish the edges out wide and shallow, about 12 times the panel thickness. Scuff 2 to 3 inches beyond that with 120 grit and mask off the surrounding finish.
Cut your glass
Before mixing anything, cut mat to fill the dished area and cloth patches slightly larger to cap it. Mat goes down first for bulk, cloth on top for a smooth face. Lay the dry pieces in place to check fit.
Laminate
Mix a small batch of resin with MEKP (chart at left). Wet the repair, lay in the mat, and stipple resin through it with the chip brush until it turns translucent. Lay the cloth over it, wet it out, and chase air bubbles to the edges with the spreader. Cure 2 to 4 hours.
Fill and fair
Stir fumed silica into a fresh catalyzed batch until it stands in peaks like peanut butter. Spread it over the patch slightly proud of the surface. Once cured, sand fair with 120 through 240 grit until the patch feels flush under your flat palm.
Finish sand
Work up through 320 and 400 grit, wet, keeping the block flat so you do not dig hollows. This kit has no topcoat in it: the patch is structural and ready for gelcoat or paint. Match your hull color before you coat, not after.
If something goes wrong
Laminate feels tacky
Normal. Clear laminating resin stays tacky on top so the next layer bonds to it. It sands fine once hard underneath.
Nothing hardened
Too little MEKP, or under 60 F. Scrape it off, warm the space, and remix.
It kicked in the cup
Too much MEKP, or it is too hot out. Cut back and mix 4 oz at a time.
White cloudy patches
Air trapped under the glass. Stipple harder next layer and work bubbles out to the edge.
Patch outline shows
The bevel was too steep. Dish edges wider, about 12 to 1, so the laminate feathers in.
No topcoat is included. Add Pure White Gelcoat or a color-matched tint, plus the 600 to 3000 Finish & Polish pack, at boatsuppliers.com.
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