Advice on Restoring 1970 Fiberglass Canoe

[Iantheman]

I have an old neglected fiberglass canoe and I am currently investigating whether or not I can repair it. I have a standard set of DIY experience so I likely can handle my way through this with some advice on steps and materials, with passable quality.

Google keeps sending me to similar threads in this forum so there must be some knowledgeable people around.

[tunnels]

Yes repair !!!
Its a good old boat and with some grinding and careful glassing you could have a really nice boat again . Will be a little heavyer naturaly but still good . The chopped strand and 18 oz woven roving day when you could make anything at all . Id start with the outside first . Take you time and carefully grind the whole outer surface and get rid of thepaint or red gel coat . The gunwhale round the top , is it possible to get it off or not ?? If not do a neat scrap and clean job in the wood and restore it at the same time . The outside id do with woven Kevlar and epoxy The same epoxy could be used to recoat the wooden Gunwhale . all at the same time !. Take the kevlar over the keel and finish it there then wen you do the other side overlap so the keel ends up with 2 layes of kevlar cloth over it .I would also yes peel ply over the top of the resin ! When it is all hard the peel ply gets ripped off and givs a good surface to gently sand and prime and paint with a two pot uretane paint . . The inside needs the same sort of treatment and grind backand get rid of all the flaking Gelcoat but do not grind into the glass scuff the surface yes to get a good bond for the epoxy coat inside!! Kevlar had excilent wear resistance and epoxy is best resin can buy so combined with the urethane 2 part paint will last for long time .
Its best to get shot of all the gelcoat on the outsdie as its extra weight and the gel is the weak place for the epoxy to bond to . Get to the glass below but not through it !!!.

[LP]

I think that I would take a slightly different tact if I were working your refurb.

From your photos, it appears that the gel coat that is still on the exterior of your canoe is still nicely bonded to the substrate. If not, then remove the poorly bonded portions. I would abrade the exterior with an orbital sander and a 50-80 grit sand paper. Depending on how involved you want to get, you can remove the gunnels (PITA) if you want to deal with reinstalling them or just leave them be and work around them.

If you need to make any repairs to the hull (nicks, gouges, etc), apply thickened epoxy to the prepared area, sand and fair.

The sanding you'll be doing is just removing any loose or poorly bonded material and to provide "bite" for the next step. After the first round of sanding go over the exterior again with a finer, 120-180 grit, sand paper. Once done with this, clean the exterior of the hull. Mask off any areas that you don't want epoxy to adhere to. Apply 3 coats of marine epoxy over the entire exterior surface to build up a protective coating over any exposed fiberglass. There are many good epoxy products on the market. Apply the epoxy with a foam roller for the best build and consistent thickness. Once the first coat has gotten tacky, apply the second coat and repeat for the third coat. If you reapply before the epoxy reaches full cure, you can avoid sanding in between coats. I you plan you day right, you can do it all in a day.

Let the build coats harden sand with 80-120 grit and finish 180-220 grit. You should have a good substrate now for a decent marine finish. You can get a decent finish with the roll and tip technique and a good marine topsides paint. Since you will most likely "dry sail" the canoe, a topsides paint will work fine. I have even used exterior gloss latex and a roller and gotten decent results. It all depends on what you want for a finished product.

On the inside, I would remove any loose gelcoat, hit it with the aggressive grit all over the inside to provide bite again for the next steps. I'd use unthicken epoxy and coat all of the areas where the gel coat is missing or cracked. Let it go tacky again and start working those areas with epoxy thickened with silica and micro balloons. There are other options for thickening. The silica is structural, but hard to sand once set while the micro balloons are non-structural, but will improve workability of the cured epoxy. Smooth the repairs and do the epoxy triple-coat and paint and you should be good to go.

This method is a little more user friendly and involves a few less dollars. If you have not worked with epoxy before, it is an excellent introduction to the process. I you do mismix a batch, you only have that coat to remove, you have fewer concerns as the surfaces you are working are essentially non-permiable and you've not ruined any cloth. It may be possible that there are areas that need a cloth treatment, but I didn't see anything jump out at me in your photos.

If there are any areas where you have cracked gel coat that you epoxied and filled, there is the likelyhood of those cracks reappearing. A complete removal of the gel coat in those areas should negate any possibility of those cracks returning. You could also glass those areas instead if you felt the gel coat, otherwise, was in good condition and firmly bonded. The risk of the crack reforming is further reduced, over epoxy and filling, but still a possibility.

Good luck on your rebuild.

[Iantheman]

It sounds like something I can tinker around with this summer and have a reliable old boat to keep at a cottage.

Both detailed posts are greatly appreciated. Time to get sanding!