I will be attempting to repair significant portions of gelcoat damage to an old, oxidized, white Sundowner that was mistreated a bit. There are probably 6-10 areas of what I believe to be only stress cracks. The repairs aren’t really needed, but I just want to have some fun repairing (if you call repairing gel-coat fun). With so much to do, I have a concern doing it the easiest way possible, but would also like it to blend in in the end. I do realize I’ll probably have to remove the oxidation from the rest of the boat in order to get a good looking color match in the end.
Pls vote for a method below. I would especially appreciate any advantages or disadvantages to either method that you can think of.
Method #1: Regular Gelcoat Repair
The local canoe shop recommended using regular gelcoat colormatched to my white hull and wet-sanding to blend. He recommended using “______ balloons” (silica balloons, I think) from a marine store to thicken the gel so it wouldn’t run.
Method #2: Cliff Jacobson’s Method.
He basically recommends white polyester putty or gray auto body putty and then spray painting and wet-sanding to blend. Here is his procedure:
. . . This procedure is easier and faster, and the finished repair is invisible.
•White polyester putty (available at marinas) or gray auto body putty. Use epoxy if you want a stronger repair. Thicken the epoxy with colloidal silica, as suggested in number 2 below.
•Sixty and 100 grit dry sandpaper, and 200 and 400 grit wet-dry finishing paper.
•Matching auto acrylic or epoxy paint.
•Fiberglass boat wax (it contains a mild abrasive) or paste wax and pumice.
- Pick out the shards of damaged gel coat.
- Catalyze the polyester putty (use extra MEKP for a hot mix) and work it into the break to overflowing. If you’re using epoxy, stir in colloidal silica until you get a peanut-butter-thick mix that won’t run.
- When the resin has cured, sand it level. Finish to silky smoothness with 400 grit wet sandpaper.
- Paint the patch. Later, use a mixture of paste wax and pumice to blend the paint to the hull.