Fiberglass Repair - How To

I need to drill a few holes in my fiberglass hull to replace my footbrace system. What’s the best way to plug up those holes? They will be below the waterline. Also, could any of you refer me to a basic overview of how to fiberglass? I want to reinforce certain sections of my deck (not to mention plugging up the holes in my hull) that are quite flimsy - and a basic overview of what kind of epoxy to use and the type of glass cloth needed would be very helpful. Thanks!

Fibreglass repair
Im not a specialist but have learned anb dnot by choice how to patch holes or chips in a glass boat. Go to a marine store such as West marine and purchase a fibreglass putty, it comes in two parts and is real easy to use, and sand as needed, I think it comes in white, black, grey and maybe red and yellow, can also be colored, sands real easy. just protect surrounding area and smear it in the holes, cracks, or scrapes.


This is what I’d do

– Last Updated: Jul-06-04 8:40 PM EST –

Clean the areas inside our boat well, cut out several pieces of fibre glass cloth (maybe 6 or 8 oz cloth?), maybe 3 or 4. Make them progressively larger, so maybe the first one is the size of a nickel, then quarter size and lastly maybe 50 cent piece. Then apply a thin coat of epoxy resin (west system or some other marine epoxy) around the hole, lay the smaller piece of glass to cover the hole, apply a bit more epoxy to wet the clothe thoroughly, then add the next bigger piece and wet it out and finally the last big piece. Then lay a bit of smooth plastic film or even wax paper over the repair and gently smooth it over the area, being careful not to move the patches. Let it cure for the night. Next day remove plastic film or wax paper and you should have a nice smooth patch on the inside, but lightly sand the area as needed. Now the hle in the outside needs to be filled with some gelcoat, if the hull is white, then just fill the hole with gel coat and leave it a little proud, after it has set start carefully sanding it down with finer and finer sand paper, finish with a wet sanding then buff it out. BNystrom has some nice pics of the process on his webshots sight, perhaps he would be kind enough to post it. Good luck.

Fiberglass Work - Bnystrom
Bnystrom, I hear you have pictures of your fiberglass process - can I take a look at your handiwork??

No, absolutely NOT! The largest patch
goes on first, and so on down to the smallest. If you think about how the largest patch spans the exposed areas of laminate, you will see why. If you want a reference, find an old copy of Charlie Walbridge’s Boatbuilders Manual. The largest patch ALWAYS goes first.

small patch FIRST!
If you put the small piece of glass on first and the largest last, you will significantly reduce the amount of time you spend sanding off the fuzzy edges of each of the smaller pieces. The patch will be smoother to begin with and you will therefore be doing less sanding and reducing the thikness and structural integrity of the patch itself. Less work/stronger patch is the result. Sorry to be contradictory, but I’ve been repairing boats for 30 years. The rest of the info posted is good info.

Great Taste…Less Filling N/M