So I'm working on my cedar strip - fibreglass Prospector. We made a bad decision about 3 years ago and took it for a jaunt down the Grand river here in Waterloo. There was one serious gash that I fixed up a couple of years ago, but since then some cracks appeared that were through the fibreglass. Of course I didn't find the cracks till after the water had seeped in. By that point sections of glass had come loose, or to be more accurate the surface layer of cedar had separated, staying with the glass but being loose from the rest of the hull. (Gives you a good idea of how shallow the penetration of the wood by the epoxy is). In addition, there were a bunch of 'dents' from the canoe being beat up over the shallow bottom. I won't claim that the hull was perfect when it was first launched, but it really took a beating in that 4 hours on the river. Not so much gouges, but some permanent flex and a bunch of hollow dents.

I started the repair by cutting away the loose sections of epoxy/cloth. These sections turned out to be a lot bigger than they first looked, but no more than say 1/8th of the surface in total and not all in one spot. Next step was to start sanding off the varnish. Two objectives here, one to feather out the edges where the epoxy was cut off, but also to get back to epoxy where I need to do the patches. At the same time there are multiple coats of varnish from the last 11 years, and it seems like a good time to clean up the smaller gouges and scratches.

The sanding is going pretty well, but there are now a lot more spots where I'm either into, or even through the cloth. On the one hand it feels good to be fairing the hull again, but on the other I'm a little leary of how far I can push it in some places.

Now the real question. The way the sanding is going, I'll probably end up with about 1/2 of the surface area with sections of exposed wood. I don't really want to add a 2nd layer of glass without taking the full first layer off. On the other hand, I think a single piece (roughly football shaped) would make more sense than a bunch of smaller patches. So, do I keep going and sand off all the glass in that area?

Thanks in advance
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It might be easier to use the scraper first when removing those layers of varnish, sandpaper loads up quickly when used dry. The scraper won't cut into the fiberglass as easily, either. The sandpaper can be used after most of the varnish has been scraped off, saving some time and paper.




Hmmm... without actually seeing the hull, not so easy to comment.. You've probably removed all the white bruises and air pockets, leaving only exposed wood and clear, undamaged fiberglass. If the damage is only on the bottom, using the curve of the strips to remove all the glass in the football-shaped area would probably yield the smoothest surface. The new layer should overlap the old by about two inches, to allow for some sanding and smoothing area in the overlap.

Sounds like there will be dents here and there, and these should be filled with clear epoxy first, then sanded fair. Once the first football-shaped fiberglass layer is on, another somewhat smaller piece in the same general shape can be added over top, for more abrasion resistance. I've done this on my cedarstrip, and as long as the edges are sanded smooth to fair with the rest of the hull, the edge of each layer is almost invisible.

You'll have to be careful not to sand through too much wood, since this might make things too flexible. This is where an extra layer or two of glass adds some compensation if hull thickness is less.

There's also the option of painting the outside to cover over damage if that's visible afterwards. The combination of wood strips on the interior and the right color on the outside can look good, even better than some not-so-well thought out cedarstrip arrangements.. Cedar canoes can provide some clues, such as dark red going with cedar wood:

http://www.sandycline.com/windyridge/lily12.html

Other colors might be dark blue, forest green, etc. that were used traditionally.

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Gosh, sounds to me like your canoe was fiberglassed with polyester resin. I beat mine very hard, even split one open last summer, and i have never had delamination occur....I've had lots of bruises and gouges, some holes right to the wood, and I've just patched theses and revarnished the entire canoe. Never had any splits through to the wood that weren't caused by a large scale gouging. Some of my canoes must have at least 4 to 5000 K of rough bush travel on them

I think building a new canoe sounds like a more enticing option than spending lots of sweat and blood on the beater.

This is the first time I've had to go through the fibreglass anywhere to do a repair. I am a bit worried about losing wood underneath, but I think I can get away with it this time. My digital camera isn't working right now, but I'll see if I can borrow one and post some pictures.

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Not polyester, West Systems, and l'll emphasize that the top layer of wood is still bound to the fibreglass, the cedar split off that layer. I'll try to remember to get a picture of a piece of the fibreglass that I cut out.

I'd say its far from being a beater still, but it does need the TLC that it's getting. The epoxy is not foggy or showing any other signs of UV damage. The other consideration is that this is an engagement canoe, my wife preferred a canoe to a ring, so replacing the canoe is definitely not my preferred approach.

It may also be worth noting that the obvious gouge isn't a place where any of the surrounding glass has come loose. That only happened in the non-obvious cracks that then got water in them.

Part of the question is how much can I get away with in re-fairing the hull. They were 1/4 strips to start with and the hull was faired when it was originally built. Due to the banging up (or perhaps stressing is a better word) it isn't fair now. Am I taking too much chance if I try to re-fair it? On the plus side I should end up with a lighter canoe. The risk is going to far and ending up spongy.

I had a second layer of glass in strip down the centerline on the outside to start with and the appearance was fine, you wouldn't see it unless I pointed it out. So I guess if I go ahead with the sanding/re-fairing and decide that with a single layer of new cloth it isn't rigid enough, then I could add a second layer at that point.

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Here's a link to some photos of the repairs in progress if anyone is interested

http://ca.pg.photos.yahoo.com/ph/rwaywell@rogers.com/album?.dir=/606e&.src=ph&.tok=phcH7oCBw0secxXR

I've been sanding away. Basically decided to sand down until it is smooth again and/or until I've gotten through the 'old' varnish. If there is glass left in an area at that point, then I'm writing it off to the cost of fairing the hull. Once I think I'm ready to re-fibreglass then I might weigh the canoe first to see if I want to second guess that.

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