Cedar Strip Canoe Repair

[alsg]

Well, what started out as a minor patching job to be followed by re-varnishing of my cedar strip canoe has turned into a big job.

After two failed varnish attempts, my overzealous sanding has caused the weave to become visible in multiple areas along the bottom of the canoe. This is almost exclusively in the so-called football area (between the two dark strips in the first photo), where I applied a double layer of 6 oz s-glass during construction.

I can't feel the weave, but even after washing in mineral spirits, the weave is visible. The close up photo is pretty representative of how it looks after wiping with mineral spirits.

I will add that the glass is still adhered to the wood.

Moving forward, I will adding some epoxy to the football area. I am doubtful it will provide any significant cosmetic improvement but it is worth a try.

Assuming the added epoxy doesn't take care of things, I see a couple of options.

1. After applying more epoxy, re-varnish and live with the patch work appearance. Advantage: easiest fix. Disadvantage: cosmetically unappealing result.

2. Remove the fiberglass from the football area and re-fiberglass the football with a double layer of s glass to match the original construction. My thought would be to attack the football with 40-ish grit on a RO using the dark strips as a visual guide. Then a two layer patch going slightly beyond the exposed wood and feather in. Advantage: best cosmetic result. Disadvantage: most work. Also, since i no longer have the forms or strongback, I'd be relying on the interior glass to hold the canoe's shape. Not sure how well that will work.

3. After applying more epoxy, build up a graphite/silica/epoxy bottom (a/k/a a black bottom). Advantage: easier than re-glassing and provides a more durable and slippery bottom surface. Disadvantage: not as attractive as a re-done clear bottom. At least one member of this forum reported a bad experiences with a a friend's black bottomed canoe bubbling up in the heat; but I have not heard of similar problems after researching on the internet, so it might have been some bad epoxy contributing to the problem.

Opinions?

 

[dogbrain]

If it were me I would go with the first option. It's fastest and easiest and gets the boat back in the water. Paddling season is here! I think you'll find that the varnish will make the areas you sanded into the glass a little less visible. Option 1 doesn't at all preclude you doing a more extensive job in the future if you find the results less than satisfactory. If you've got a double layer of 6oz cloth on the bottom, there's plenty for structural support even if you sanded into it a little. Having these blemishes on the bottom only is the best location because that's where the boat gets scratched up anyway.

Mark

 

[memaquay]

I'm with Mark on that. the bottoms of most of my cedar strips are like modern art, the kind that no one understands...full of patches, scratches and gouges. the bottom only gets seen on top of the car or by fishes.

 

[Jim Dodd]

With two layers of S-glass, don't worry about it ! S-glass is more visible than E-glass. That's the way it is ! Many people get by with just one layer of 6 oz E-glass. You have plenty of protection on that nice looking hull, by the way !

Clean the hull thoroughly with Denatured Alcohol get rid of that mineral spirits ! Start with a new can of either Helmsman Spar varnish or Varithane Spare varnish ! Don't dilute !!

This weekend I sanded a hull that I built for my oldest son a couple of years ago. There were a few flaws, so I gave it two more coats of Spar Varnish ! After sanding, I cleaned the hull, with Denatured Alcohol, foam brushed two coats of Varithane's Spar Varnish, about 6 hrs apart, done ! Temps in the low 60's F. This hull was originally Helmsman coated. No diluting !

Denatured Alcohol, leaves no residue like Mineral Spirits can.

I would do the same with yours , if it was mine and here.

Good luck ! You've had more than your share of Bad luck already !

Jim

 

[stripperguy]

I’m with Jim
clean it well add a couple coats of quality varnish and call it done
Remember, every scar tells a story!

 

[alsg]

Thanks for the advice, all. I ordered Epifanes.

 

[memaquay]

Seems to me, might be a good time to build a new canoe, just say'n, that one is giving you more trouble than an ex-wife. Build a new one, keep that one as a loaner.

One question though, what brought about your decision to use S glass on the bottom? Two layers of s-glass would definitely be harder to work with with a hand layup, I would think it would suck up a lot of epoxy. Knowing that it is s-glass, I would not worry about putting more epoxy on top of what you have. If, as you say, the weave is buried, but showing, more epoxy will probably not make the showing weave disappear. I'd just slap the new varnish on it.

 

[alsg]

This was my first build (only build to date) so I read a lot and decided to use s-glass for the extra strength. For the same reason I reinforced the football with a second layer of s-glass glass (both inside and out, by the way). It was perhaps perhaps overkill. But the boat will never oil can, that’s for sure! None of the bottoms scrapes got into the glass. And the only damage to strips on this canoe has been in the areas just above the water.line where that reinforcement stops. So if anything, I wish I had extended that double layer a couple or more inches It does add weight (16 ft canoe weighs sixty five pounds) and suck up epoxy and creates some challenges for a hand layup that were likely complicated by this being my first build.

Another build is is in my future. Probably a solo boat.

 

[Jim Dodd]

Using S-glass for the entire hull with double layers on the bottom, inside and out, is definitely over kill ! Also pretty tough !
The extra layers, is where your weight comes from, and the extra resin ! I just add S-glass to the outside, up to about 3" waterline. That's plenty !
It shouldn't soak up any ext resin, than E-glass ! If you would have used E-glass instead, I believe the weight would have been the same !

E-glass is maybe a third of the cost of S-glass !

Yes, on the Solo build ! The real beauty in my opinion is, when You want to go paddling ? You only need to fit it into Your schedule, and not someone Else's ! Go for it ! Not to memtion the Solitude !!

I'd build it with E-glass, and just a double layer on the outside, up to about 3" waterline. Yes the double layer will add weight, but stiffness and durability also !

Good luck with the Epifanes ! It is a good choice !

Jim