Canoe Repair Questions

I got a new to me kevlar canoe that needs work.

  1. Should I replace gunwales, thwarts, and struts before patching holes? I assume yes but figure I’ll borrow community experience =)

  2. this boat will live outside(and did bfore I grabbed it) so I’m assuming it’s better to replace the gunwales with aluminum ones. Any reason not to ( not worried about aesthetics)?

  3. the center (and only) thwart has a vertical strut in the middle that attaches to an interior keel (assuming foam). Can these elements be replaced with aluminum or is the wood providing a springiness that protects the boats structure in waves? Like question 2, I’d like to replace these with aluminum if there’s no reason not to.

  4. Fiberglass patch advice. For holes/scratches going all the way through and scratches that show a white line on the interior, how many layers of cloth should I use? I assume I should use s cloth. Should I apply one layer on the exterior and n on the interior or should they all go on the exterior/interior? I’ve never done this repair before so my other question is confirming I sand down where ever I’m applying until I see bare fiber, right?

The hull was solid at pickup but the gunwales disintegrated loading it into the car and center thwart fell out one side and off the vertical center strut on the drive (stayed in the canoe due to other side). As a result, I need to replace the gunwales, maybe the thwart, and repatch some patches that came loose due to the hull flexing on the drive with no side to side support(I learned to always bring lumber and wood screws when graving a used canoe). All of this background info for the questions above.

Thanks much in advance.

Photos would help.
Aluminum gunwales are easiest if you can find some to fit your boat. I like white ash seats and thwarts and they dress up a boat in a hurry. Don’t be afraid to adde 3 thwarts so you can stiffen up the hull and have lash points for equipment.

Grind or cut the bad fiberglass. Use marine epoxy and S glass is fine. I have repaired some really big holes and rips in fiberglass boats with good success. Kevlar is not that different. It is just harder to grind because it tends to fuzz up. Patch the hole with a small patch. Then add a layer on the outside and one on the inside several inches larger than the hole.

The first pic is the crack. The next 2 are follow up questions, a chip in what I’m guessing is a gel coat that’s largely disappeared and more image of the disappearing gel coat, am I looking at exposed fiber, kevlar or s cloth? After the gunwales and patch, would the right move be to clean the boat with alcohol and add a coat of UV epoxy as a new finish coat? I know the boat needs a wash.

If it were mine the first thing I’d do is tape off around that hole and sand the edges of the hole to make sure you remove any loose pieces, then make sure it’s good and dry ((hairdryer, sunshine) and fill it with epoxy. People like G-flex best. I would want that hole filled immediately because if water gets in the fabric you could have bigger problems.

Then I’d scrub the snots out of it with a stiff bristle brush and Bartenders Helper (any non-abrasive cleanser). The crack (cracks?) look big enough to create a soft spot so people typically put a fabric patch on both sides. But you’ll first need to clean out the cracks and remove any previous repair material.

Regarding a vertical strut aluminum will work same as wood. No problem with aluminum being stiffer

Regarding gunwales the biggest factor may be how to get them. Do you have somewhere nearby where you can pick them up? If you order full length gunwales you will pay perhaps $1000 for the semi-truck to deliver them to your house. People sometimes ask local canoe dealers if they can get gunwales shipped along with an order of canoes so they don’t get slaughtered with shipping costs. sells wood gunwales that are cut into sections small enough to be mailed…they might be your best bet depending on your situation. Maybe not as ideal as aluminum for outside storage but a quick once/year coat of varnish and you’ll be fine.

For the outside finish I think your idea is fine; I’ve never done it. I think the Souris River site has instructions for refinishing Kevlar boats using varnish. Looks pretty easy.

What are the bigger problems with water in the fiber? I ask because I was transporting this in the rain so it’s likely those bigger problems may already be here. What should I look for?

I’m assuming delamination from reading about it. No signs of it… Yet. I’ll cover up ASAP to prevent it. Does the fiber wick the water? This seems like a foam problem which is only at the keel for this boat. I might be misunderstanding any number of things so please correct me where I’m wrong.

Regarding cleaning out the cracks, what’s the difference between good and bad fiber/kevlar at this point? Won’t it all get reimmersed in epoxy? Do I need to sand down the sides where the cloth will go on top or just clean them? Sorry for so many questions. I’m a total newb to this

Regarding the gunwales, I’ve got a dealer about 1.5 hrs away so I might just go there. I could use a new paddle anyway…

Greatly appreciate your and ppine’s responses.

Kevlar cloth is much different to work with than fiberglass. You cannot simply cut it with scissors. The easiest way is to buy a special pair of kevlar cutting scissors, usually available from the companies that sell the kevlar itself. I have found marine epoxy (West brand) works well. As you already seem to know, you cannot sand the kevlar itself after the epoxy hardens, so be sure the epoxy is smoothed out over the kevlar, sometimes requiring a second thin coat. Good luck.

Thanks for the tips j Scott.

I haven’t read all the replies, so I don’t know what has been already suggested. But I will add this: I talked to Wenonah before patching one of their Kevlar canoes. They said to use fiberglass cloth for patches – it is much easier to work with and won’t add enough weight to matter. And patches are on the inside of course.

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Thanks, Albany. I found this earlier and it answered several questions I have and seems to line up with advice this far.

The only question that still comes to mind (I know there will be more) is do I just need to remove loose resin and gel coat? I’m thinking any frayed fibers will just get rewet and immersed in the new epoxy without structural impact. Others thoughts?

Many of my repairs have been alongside the river. I always travel with a repair kit. Sanding, epoxy, hardener, disposable natural bristle brushes, disposable gloves, fiberglass cloth, etc, takes up about half of a 5 gallon pail. And, I have made those repairs in 22F and 110F patches inside and outside depending upon the injury. Cleanliness and dryness. Not wet, not white.
Gunnels. You and I may have purchased the same boat. The ash gunnels are trash on the 18’ Sundowner. Hull is still excellent. Gunnels are the heart of a canoe. And the gunnels are held in place with the yoke and thwarts. It is imperative that the thwarts are symmetrical withing the total of the boat. Leaving the space at your feet a bit longer, induces an asymmetry that weakens the total.
I successfully replaced the gunnels with epoxy, glass, and cedar, multiple thin layers, worked great. I will do something very similar on this new/old boat. I am not a fan of aluminum,(the very first small dent reduces strength by 90%) , but Big Drop 3 in Cat would squash about anything. The cedar and glass layup has survived a spring time pin on the San Juan and other displays of ineptitude in Class III and Class IV. The new/old boat is a wet foot boat, I won’t be able to bash and crash with the same abandon. But the extra strong gunnels will make loading and truck top transport a breeze.

I didn’t get into things gnarly enough to worry about aluminum gunwales damage but I love the idea. I’ll keep it in mind if and when I’m able to start doing more ww.

I hope the takeaway for you is do not hesitate to build your own gunnels. When you get to white water and multi day or multi week trips, a full splash deck is a requirement for Class III and up. You go through waves as often as you go up and over.

Appreciate the advice. Don’t think I’ll have the time this go around.

That boat has been around awhile. Fiberglass ages especially in the presence of UV light when stored outside. Do some careful investigating of this boat in bright sunlight. Press on the hull. It may be brittle by now. If it still has some flex you can repair it. I would wash it and then do some sanding and get the rough paint and gel coat off the hull. That gives the new fiberglass something to bond to. When you finished just prime and paint it.

I have talked with Mike C at Wenonah about repairing kevlar boats. We talked about fiberglass cloth and epoxy, nothing exotic. You don’t need kevlar cloth, special scissors or special materials to fix a canoe like that. You could even use plain old poly ester resin for an older boat.

Realize that sometimes old fiberglass boats can just give up and fail. I had an older kevlar canoe start to fold up on me on a lake. That was after some rigorous river trips a long way from any help. Paddle your boat near home for awhile to make sure it is strong enough for other trips.

The hull flexed plenty well on the drive home. What opened up was an old repair. Point taken though. Knowing me the repairs won’t be done until next year. I’ll keep it local for another year until I’m sure it won’t disintegrate on me.

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