Repairing cracked gelcoat on a fiberglass canoe

[Primitive Pete]

Need some help in choosing the right material to repair a gelcoat covered fiberglass canoe. The gelcoat covering has very shallow cracks throughout the entire surface. These are not isolated impact cracks. The canoe does not leak. There is also one small 1/4" hole above the water line. Have sanded the entire canoe with 80 grit sandpaper. Cracks are still visible but very shallow. Despite the cracks the gelcoat seems solid. The 1/4" hole has been sanded down to fiberglass and beveled out 2" around the hole.

I know how to repair the hole with polyester resin, fiberglass cloth and hardiner. The area where I need the most help is repairing the cracked gelcoat.

Mending gelcoat - I do not plan to sand down and remove all the gelcoat, then recoat with gelcoat or fiberglass. Way too much work and not worth it. Have been told it is not necessary anyway and that satisfactory results can be had by sanding out as much of the cracks as I can with 80 grit sandpaper, which I have done. Then fill the remaining cracks with something durable, finish sand with 150 and then 220 grit sandpaper and paint. The suggestions for the "something durable" to use to fill in the shallow cracks that are left are polyester resin, epoxy resin, white polyester putty or gray autobody putty. When filling deeper cuts and gouges it was suggested to mix colloidal silica into epoxy resin to thicken it. I have done some body work on cars using fiberglass and Bondo but think using the epoxy resin to repair this canoe might be the best option. Have also been told no matter what filler I use, if I don't sand out all the cracks completely the cracks will just come back in a month or so.

One article I read but can't find now said either the polyester OR the epoxy resin will not stick to gelcoat.

Hopefully someone here knows what would be the best products to use to finish the job. Not looking to get commercial quality results, just a half way decent finish. If the cracks come back I can live with it. Just want to make sure the filler and paint I put on doesn't peel off.

 

[fuzzeywiggler]

Re: Repairing cracked gelcoat on a fiberglass canoe

Can you get a pic of the cracks? are they just spider cracks? Don't use bondo it absorbes water,

You can use gel coat or marine tex its up to you if ther are deep.

Fuzzey

 

[ondarvr]

Re: Repairing cracked gelcoat on a fiberglass canoe

Sorry, but there's no easy way to fix gel coat with the problem you're describing. The cracking or crazing gel coat needs to be removed completely or when you repaint it the cracks will return, possibly before you even get it in the water. There are no coatings, primers, sealers, paints, fillers or other products that will hide or fix them without sanding them until there gone. Truck bed liner would, but I don't think you'd want that on the outside of the canoe.