Repairing collision damage on a Laser sailboat. The Laser is a lightweight boat that’s decked over, so most repairs have to be made from the outside. I used epoxy for the structural repair because its stiffer and bonds better to the original polyester layup. I switched to polyester for the filler (Bondo) and gelcoat. Many people warn not to do this. I find it works fine as long as the epoxy has cured at least a week, and has been thoroughly cleaned of amine blush and well sanded. These techniques can be used on any fiberglass repair where only one side is accessible. Be sure to extend the bonding area well outside of the original damage. This repair was done over 3 weekends. Don’t despair – fix that boat and get out there again!
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Thanks this helps a lot. my whaler just got a huge hole in it from the bunk of my trailer sliding off, and the bench for it dug at my hull so I have a whole about the size of a gallon jug, but with the insulation on the inside it should work like the glass that you just pushed back into position. Thanks for the helpful vid
@TheReal308 Yes! The damaged sections formed the basic shape of the repair once the gelcoat was ground away. If I just cut a hole, it would not only form a stress riser, but I would have had to put a shaped mold on the inside, a real problem on a decked-over boat like this. The added ‘glass equaled the original layup thickness. Cutting away the damaged stuff would have only saved a negliglble amount of weight.
Is there a reason you didn’t cut all the damaged glass out?
@paton108 Thanks! Send me a picture of the repair when its done – webmaster@laserd8.org
just what i needed ,thanks well done,from australia
@drummer25664 – Part 2. If you can reach the inside, layup cloth or matt on both the inside & outside in 1 glue-up. Its stronger. If you build up enough cloth, it should sand out w/o strands showing, this is only a problem when you use a mold. You’ll probably need filler, though, to get the final contour. But, Bondo is cheap!
@drummer25664 – Sounds like this is a fiberglass fender on your truck. Since it was probably painted, you could probably skip the gelcoat and go straight to paint. Since paint is thin, you’ll need to cover the repair with glazing putty (auto body stuff) otherwise, the graininess of the bondo & the porosity of the cloth layup will make your finished paint look like sandpaper. I use gelcoat when matching to a gelcoat finish around the rest of the boat (or fender). See part 2.
I am repairing the rear fender of a dually and have the piece that was knocked out. about a 4 inch square pc. A clean break . can I use the matt and cloth on the outside as well? no gel coat? will the cloth sand out good without seeing strands? or do I only use the matt and cloth on the inside of the fender with gel coat on the outside as a final filler?
Thanks! Of course, this isn’t the only way to do this kind of repair, but I hope this gives people the confidence to tackle fixing this sort of damage. The people who make West System Epoxy have some good books on this kind of repair, you can usually find them at marine supply stores that carry their products.
great , instructional , informative, interesting… Many Thanks for posting
not a clue
All of the materials used was stuff I just had lying around. The cloth was about 6 oz. I didn’t have to use matt, but it was donated so I used it. Matt has a sizing that dissolves in the MEKP catalyst used in polyester, but it doesn’t seem to have any ill effects with epoxy. If you are going to pick up just one material, use cloth. I try to roughly match the weight of the original material, but its not too critical. If you mess up, just grind it off & try again!
what cloth / weights did you use?
The reason I ask is cos you use matt near the surface and I thought this was not so good with epoxy as it is coated specifically for polyester
great video