Need advice on repair bottom… scratchs…Thinning bottom is there some motor boat - sail boat stuff that I should check out? Don’t want to ruin the great glide…
Is the outer layer gelcoat?
If so, are the scratches only into the gelcoat, or do some cut into the fiberglass?
There isn’t enough objective evidence about whether a smooth bottom (as on a new boat) glides better than a scratched-up bottom. I have resurfaced a couple of boats, by rolling on epoxy and sanding smooth, and I thought it made the boats faster, but I sure can’t prove it.
My boats had no gelcoat. If, as is probably the case, your boat has gelcoat for the outer layer, then someone may come forward to advise on how to build up the gelcoat and make it smooth again.
A more conservative approach is to just wipe epoxy into the deepest scratches and leave the rest alone.
Gelcoat repair on 1990 Hull
Canadienes, whether by Chicagoland Canoebase, Bell Canoe or Old Town were gel coated.
There is lots of evidence that scratches increase surface drag and slow forward speed. The best, short, info is page 21-22 in John Winter’s “Shape of the Canoe”. Doubters may contact John - I’m sure he’ll provide references.
In extreme summary, a new gel coated hull has a 1 mil surface roughness, a badly scratched hull 40 mills. A moderately scratched hull has half again the surface friction of a new model.
Let’s assume we’re dealing with a 40 mil problem.
A gel coat match is pretty rough after seventeen years, but MiniCraft of Florida has a kit that will get you pretty close.
For a few gouges, set up outside on a clear, warm day in cloths you may never wear again. Have eye protection and rubber gloves. Clean deep gouges with acetone and a rag. Catalyze an appropriate amount of gel, smear into the scratches with a craft stick, having cut one end square. When solid, wipe w/ acetone, sand out with 120 dry, then 320, 600, 100, 1200 wet paper. Buff with rubbing compound.
Repair of the entire bottom is a little more involved. Mark the waterline by taping a magic marker of similar color to a short piece of 2X4. With someone holding the hull upright on a smooth concrete floor, move the block around marking a 4" waterline. Turn the hull over; sand the marked bottom lightly w/ 120 or 220 grit and wipe with acetone. Run tape along the line, then mask below it, with newspaper or plastic protecting the sides of the hull.
Armed with a couple cans of the best spray enamel available, paint the bottom whatever color moves you. Peel the tape and the masking while the paint is still wet/ When dry you’ll have a 2 mil surface that can easily be touched up with the remains of the second aerosol can.
Yeah, you can spray gel coat, then sand the bottom through the above sequence to get a 1 mil surface, We’ve done it, but few paddlers have respirators, a spray booth, a cup gun and compressor etc.
Thanks for taking the time to reply…
Thanks for your comprehesive reply … do you have a web site or address on the Florida company? I am assuming the match is important…I brought the canoe used - $250 and it is good shape a couple dings in the stern and bow where they must have slammed into a rock and scratchs on the bottom… rigged for solo… I tested it in a lake once and frankly was a little nervous about taking it on the current river but I bought it to use and some reviewers said it preformed well in class two and three rapids … the current does not have class two or three rapids (I and II with rocky bottom) but if you were going to classify snags and deadfalls it has some class two and three of those…it is a beautiful wiilderness river in Misouri and one of the last you can river camp on… I was nervous about its turning ability and lack of rocker…well when I took the canoe out it preformed well… I had to just be more of an advance planner and try not to put myself in situations that needed the tight turn to survive…the other thing I noticed was in the area of the solo seat… (my big self) it was not scratched but thining moving towards the pink… anyway I like the boat and do not want to damage it… you know the do no harm thing…it was a little differant but very satisfying paddle… any suggestion on a emergency repair kit to take with? Duck tape?
a little clairity on your advice… if I was going to do the whole bottom… would I gel coat the scratchs first? and then paint it? Could I apply a second coat of gel coat on the area that was thinning to build it up? Would that create drag?
would I apply gel coat to the dings in the bow and stern the same way as the bottom?
thanks again for taking the time to reply
Curtis Nomad paint job
A few years ago a bought a used Curtis Nomad that was badly scratched over the entire bottom. The wood gunnels were also rotted and needed replacing. The hull was not compromised in any way and none of the scratches were deep enough to reach the fabric. I elected to sand the entire hull with an obital sander to remove most of the surface scratches and then took it to an auto body shop and had it painted with a good auto paint. I figured they paint Corvetes, which are fiberglass, so why not a canoe. It came out beautiful - looks like a new hull. After I made new gunnels it looks like a brand new boat at less than half the price. It has held up well the last two years but you should know I baby all my canoes to avoid scratches in the first place.
Just my two cents worth.
Spraying Gel Coat
You mention spraying Gel Coat. I recently acquired a Tuf Weave Wenonah canoe that is about 10 years old and needs a complete refinishing. I own a compressor, HVLP gravity cup gun and everything else I need. I have years of experience painting in an industrial setting. Any tips, tricks, or advice you can pass along on spraying Gel Coat? Thinning? Reducing solvents? Thickness?