Gunwale repair options

[Halpc]

We had a stupid accident yesterday- the front tie down rope was not tied and went under the tire of the truck. The wood gunwales on my recently acquired 1988 kevlar Mad River Malecite were damaged in the resulting quasi explosion. The prior owner had oiled them some and there is no rot (we are in a very dry climate in Utah) but the wood is probably drier than optimal. I had sanded and oiled them with Watco right after buying the boat. The damaged wood is splintered and rough- not a clean break or broken all the way through. Has anyone tried infusing gflex into a break like this rather then splicing in a new piece of gunwale? The boat is kind of a rescue project and far from pristine. Functionality is a higher priority the appearance, but I would like to make it look presentable. The PO had removed the center thwart which, based on my research, was under the center seat, and lowered all three seats using drilled dowel hangers. I suspect that the lack of support may have caused the multitude of gel coat cracks in the hull. We added a thwart and raised two of the seats to stiffen it. I really like the way it paddles now, especially solo with the slightly canted seat. It also poles very well. Do I need to try to find some kerfed gunwale splints or is it worth it trying to fix it with glex first? I am a fan of gflex after my son and I were able to “rescue” a 1990 vintage Royalex ME which had about 25 bad cold cracks. It is running fine again.
Thanks for your help.

 

[Halpc]

Forgot to add the photos.

 

[dougd]

I'll throw my 2 cents in. I'm a fan of G-Flex, been using it for years. I'd be tempted to somehow separate the break in the gunwale, maybe a V cut?, and then jam some thickened G-Flex in between the break, put some Peel Ply on it and on top of that tape it down. My only reservation is the how does oil mix with G-Flex? That is something I haven't done before so don't know about the bond. As far as that nasty arse crack in the hull I'd throw some Dynel mixed with G-Flex and resin mix to seal it up after cleaning it up best you can. Dynel as it's good for abrasion and it looks like it is in the chine area of the hull. If you don't have Dynel on hand I have quite a bit and if you send me the dimensions of the crack I could cut a piece to cover it and send it on. Good luck and please keep us posted.

dougd

 

[alsg]

I feel your pain! Last year I fell backward into my bow seat while poling and shattered a gunnel. You can absolutely repair the gunnel with regular epoxy thickened with microfibers (and a little sawdust if you want to match color). I wouldn't use G-Flex for this application.

But you are going to want to get the loose pieces off, even if you have to pull them off/saw them off because you want to make sure the thickened epoxy is where it needs to be. Butter up everything with thickened epoxy and clamp back together. Light clamping pressure.

Here's some before and after of mine.











I had wanted to move my bow seat before the accident, so I filled the bolt hole; but the epoxied gunnel is just as strong as it ever was so you can reuse the same bolt hole if you want.

 

[Glenn MacGrady]

Has anyone tried infusing gflex into a break like this rather then splicing in a new piece of gunwale?

Yes, I have. It wasn't a break caused by an accident but by isolated rot. I first detailed the problem and got a lot of great advice here in this thread:

Need advice to repair cracked inwale

Then, I documented my entire gunwale prep and G/Flex repair, including tools and cleanup, in this detailed video:

Finally, I discussed the video repair and provided finished photos in this follow-up thread:

Video: Epoxy Repair of Rotted, Cracked Gunwale

Seven years later, the repaired gunwale has had absolutely no problems and is still strong.

 

[Larry650]

Oh Man that hurts! My favorite all time boat is my Kevlar Malecite. Because I have one, and am very biased, I vote to replace the gunnels. But what about that damaged hull? That looks like the big problem to me. I think I might call my auto insurer and see if they can help put the old girl in the canoe hospital.
BTW, I have the factory center seat also. Makes it a great solo canoe. Love the Malecite. Let us know what the outcome is.

 

[scoutergriz]

The problem I see with your breaks compared to the others is that yours is straight across the grain, while theirs have at least some degree of splitting. That means that yours has comparatively less surface area to bond, add in the fact that it's already a stress point caused by the arc of the bent wood and it could be trouble. I'd be tempted to at least splice in a 11/2-2' section of the inwale to move the weak points away from each other to regain some strength and rapidity, the split section is already essentially scarfed for you.
the hull damage looks to be mostly gelcoat and therefor cosmetic, if the fibres are good a little epoxy filler and a can of auto touchup paint and you're good to go, if they're fractured, I'd patch the inside, remove any lose gelcoat, and add a layer of glass or kevlar to the outside and sand it fair to the hull before painting.

 

[Cruiser]

The problem I see with your breaks compared to the others is that yours is straight across the grain, while theirs have at least some degree of splitting. That means that yours has comparatively less surface area to bond, add in the fact that it's already a stress point caused by the arc of the bent wood and it could be trouble. I'd be tempted to at least splice in a 11/2-2' section of the inwale to move the weak points away from each other to regain some strength and rapidity, the split section is already essentially scarfed for you.
the hull damage looks to be mostly gelcoat and therefor cosmetic, if the fibres are good a little epoxy filler and a can of auto touchup paint and you're good to go, if they're fractured, I'd patch the inside, remove any lose gelcoat, and add a layer of glass or kevlar to the outside and sand it fair to the hull before painting.

I think SGz has the right of it about the gunnel breaks, when you go across the grain like that, there is little strength if you try and glue/epoxy the break.

I did notice that theses gunnels appear to be screwed on and in this case it makes then easier to remove. I also noticed they have some age on them, which will make the wood a bit tougher to "match", this doesn't matter from a performance view, only aesthetics.

Rather than fool around and try to repair the gunnels, it might a lot more straight forward to just put on a new set, either buy a gunnel set from a place like Noahs or just rip up a set if you are so inclined.

The second alternative would be to remove them, cur out the broken parts and skarf in new pieces, then trim to length, I would take the time to sand them down a bit and this would likely make most the wood look about the same. Minimum skarf ratio should be 9:1 or higher to maintain strength.



Brian

 

[Halpc]

Thanks to everyone for your very informative replies and the link to the video. It does appear that the hull damage is primarily the gel coat "flaking off" when it was bent. The kevlar isn't visibly torn. Do the white lines (last photo) on the interior indicate that there are problems with the underlying kevlar? We will document the repair process and post the results. Thanks also Dougd for the Dynel offer- we may take you up on that.

 

[scoutergriz]

without closer examination it's hard to say if the fibres are damaged the white could just be stress marks in the resin, you'd need to look closely for "fuzzed" or parted strands, if the strands are intact you could just sand down to the material and recoat it for a cosmetic repair. If there are damaged strands or a soft spot (considering the lack of gelcoat) I'd rather be safe than sorry and put a patch over it.

 

[Jim Dodd]

I recently replaced a set of Gunnels on a MR tandem. If you could find a new set at a reasonable price ? Shipping now days is atrocious !

I made a set. Had enough full length (18' 6") Ash. It was still a pain to duplicate the lip and profile contours.

Dealing with shorter Stock would have been easier, to machine, to shape and splice.

Any Grain flaws in the gunnels are a sure bet for future breaking .

Good Luck !

 

[pblanc]

Tempting as a quick and dirty repair might be, I would scarf in a new segment of inwale and outwale. Especially the segment of broken inwale that supports a seat hanger carriage bolt. Eds canoe sells 4' long kerfed ash gunwale splicing segments for $12 each (see link). That would not be that hard and would be infinitely easier and cheaper than rerailing the whole canoe. Put the kerfed segment on the outwale side. Either plane off or sand off the kerf on the inwale side. I use G Flex to bond the scarf joints and it adheres very well to ash. https://www.edscanoe.com/kerfedgunwale.html The gunwale splicing segments are slightly oversized so you would need to trim and sand them down a bit to match and also contour the outwale but that isn't that difficult.

As for the length of scarf joints although 1:8 or even 1:12 ratios are often recommended, I have used and been perfectly satisfied with much shorter scarfs of 1:3. perfectly durable and I think they are less noticeable. In fact, if you go through this pdf file from Mad River Canoe on wood gunwale repair/replacement starting at page 19 you will see that MRC recommends cutting the scarfs at a 30 degree angle. A 30 degree angle produces a scarf ratio of 1:1.73. When you are joining very thin panels together you need long scarfs to provide sufficient adhesive bonding surface and it helps with alignment. With pieces as thick as inwales and outwales there is plenty of bonding surface with a much shorter scarf ratio and the alignment is dictated by the sheer of the canoe and the pieces are kept in alignment by the gunwale screws. An angle of about 18 degrees will produce a 1:3 scarf ratio.

I think the hull damage is significant, not just gel coat. I see what I believe to be broken fibers of what looks like fiberglass roving peeking out from under the cracked gel coat. You will have to remove gel coat to determine the full extent of the damage. I suspect you will find the need to apply an external patch. Personally, I would use S fiberglass for that. The light colored lines on the hull interior are the result of Kevlar fibers breaking out of the resin matrix. The aramid fibers are stronger than their bond to the resin so they don't usually break, just pull away. But the hull there is weakened. S fiberglass could also be used for an interior patch of that area.

In a way you are lucky. I have seen folks snap off the entire bow of a canoe that way.

 

[Cruiser]

PBlanc .... a skarf at that low a ratio on end grain (which this will be) would be pretty weak ... it wouldn't fall apart, but there is little chance it will survive much stressing ...

 

[pblanc]

PBlanc .... a skarf at that low a ratio on end grain (which this will be) would be pretty weak ... it wouldn't fall apart, but there is little chance it will survive much stressing ...

I speak from personal experience, not theory. I have repaired broken wooden gunwales on several whitewater canoes that have received hard use and they have held up just fine. And if you look at the pdf file I posted, Mad River Canoe recommends using scarf joints even shorter than 1:3 to splice in repair segments on their wood gunwale canoes. I doubt that they would have done so if a lot of people followed their recommendation and had the joints fail.

Have you used a 1:3 scarf joint to repair gunwales and had it fail?

 

[alsg]

pblanc The link you posted didn't work for me -- or at least didn't have any information on gunnel scarfing. But I think this the document you are referring to. https://www.madrivercanoe.com/us/ex...od-gunwale-repair-installing-splicing-section It does indeed recommend an angle of only 30 degrees.

It may work but such a short scarf goes against everything I've ever read about the proper scarf joint ratio needed to ensure no loss in strength in the scarfed area as compared of the original board.


When you have used this method, have you done it on a section of inwale that a seat was hanging from?

 

[pblanc]

pblanc The link you posted didn't work for me -- or at least didn't have any information on gunnel scarfing. But I think this the document you are referring to. https://www.madrivercanoe.com/us/exp...licing-section It does indeed recommend an angle of only 30 degrees.

It may work but such a short scarf goes against everything I've ever read about the proper scarf joint ratio needed to ensure no loss in strength in the scarfed area as compared of the original board.


When you have used this method, have you done it on a section of inwale that a seat was hanging from?

Sorry about the link. The pdf file is available online and you can download it. Apparently the size of the pdf file precludes linking to it and when you try to the link just defaults to Mad River Canoe dot com.

If you want to see the whole guide do a google search for "mad river canoe gunwale replacement pdf". On my computer the first entry that search returns is labelled "Gunwale - Mad River Canoe" which when you click on it opens an 11 page pdf file covering replacement and repair of wood gunwales on Mad River Canoes. There is an even larger pdf file further down in the search return list titled "Mad River Canoe Care and Repair Guide" which covers repair of IQ and vinyl gunwales, gunwale maintenance, and a bunch of other stuff.

If you open the first, shorter pdf file pages 8-11 cover wooden gunwale repair with splicing segments. Unfortunately, attachment size limitations prevent me from linking to even a single page of the file.

I have repaired both inwales and outwales of two Royalex whitewater canoes, a Dagger Rival and a Mad River Outrage, and one broken inwale of a composite whitewater canoe (Mad River Twister) using 1:3 scarf joints. Being whitewater canoes none of them had suspended seats, they all had foam pedestals. In at least one of the canoes both inwales had to be repaired/replaced across a segment to which a thwart was attached. Whatever weight is born by one of four seat hanger machine screws would not be born solely by the scarf joints of a spliced inwale segment. It would largely be born by the gunwale screws holding the inwale onto the hull and the outwale. And if this was a concern the inwale splicing segment could also be epoxied to the hull.

I'm really not going to argue whether this works any further. I have done it in canoes that have seen hard use, probably harder than the average Kevlar Malecite sees and I know that it works.

 

[Guest]

Looking at the photos of the gunwale damage, both inwale and outwale, some splintered lengthwise, some shattered cross section and at least one broken at a seat hanger, I’m with Larry and Cruiser; if you have the woodworking skills and access to long hardwood planks I’d rip and route replacement gunwales.

Or buy something like a set of Ed’s Canoe knock-down (scarfed) gunwales. Except you can’t right now; Ed’s is out of stock

https://www.edscanoe.com/14kndogusy.html

Lacking a new gunwale option scarfing in new wood will work, although matching the old gunwale profile, grain and color may be a challenge.

My last option would be to try to epoxy the breaks back together. Given the raggedness of one across the grain break the pieces might be difficult to seat together well married, and I’m not sure how epoxying would best be approached. In this case gunwales removed from the hull for easier alignment/clamping?

If either approach, epoxying the breaks or scarfing in new wood, is best done with the gunwales (seats, thwarts, deck plates) removed you are already part way along a path to installing new gunwales.

But all of that really depends on your skills and aesthetic desires.

I’m with Pblanc on the hull damage

I think the hull damage is significant, not just gel coat. I see what I believe to be broken fibers of what looks like fiberglass roving peeking out from under the cracked gel coat. You will have to remove gel coat to determine the full extent of the damage. I suspect you will find the need to apply an external patch. Personally, I would use S fiberglass for that. The light colored lines on the hull interior are the result of Kevlar fibers breaking out of the resin matrix. The aramid fibers are stronger than their bond to the resin so they don't usually break, just pull away. But the hull there is weakened. S fiberglass could also be used for an interior patch of that area.

I’d patch with S-glass, covered with release treated peel ply, both inside and out. That may also present aesthetic issues

In a way you are lucky. I have seen folks snap off the entire bow of a canoe that way.

I’ve seen the effects of friends driving over a loose bowline thrice. Each time, I should note, when folks were hurrying, rushing and/or distracted

Loose bowline tied off to a vinyl gunwaled Old Town deck plate carry handle. Tore the plastic carry handle apart, no significant hull damage.

Loose (very thick) bowline tied off through lining holes on a vinyl gunwaled OT Tripper. Crushed the van roof and shattered the windshield, no significant hull damage.

Loose bowline on a wood gunwaled kevlar Rendezous. Basically destroyed the canoe; splintered the inwales and outwales on both sides, folded the hull over with massive damage to the fibers, producing gel coat cracks everywhere for several feet, crazed like a piece of broken safety glass. The owner had paddled that canoe once. And never again.

Loose bow lines are a hazard. I keep mine tucked under the painter keeper bungees until I am ready to release and tie down. If I get in the driver’s seat and there are no bow lines visible, that’s a clue. More critically, once I start tying off a bow or stern line I don’t take my hands off the rope ‘til securely tied; distraction is evil. And nobody ties my roof rack lines but me.

Eh, I learned a belly line lesson the hard way. We were hours late to the put in and a non-paddling friend was running the back shuttle with my van, driving it down to the take out where we had left his car.

In a hurry (again, hurry rushing and distracted, both best avoided when it comes to canoe lines) I asked him to wrap up the belly lines, which stay attached to the roof rack. I did not provide specific instruction, nor check his work; he coiled the lines and left them dangling unsecured.

One belly line fell loose on his way to the take out. It went under a rear tire. And tore the roof rack off, leaving a giant gouge in the van roof.

So yeah, I think I’ll handing tying, untying, securing and checking all of the lines myself, undistracted. I don’t need “help”.

 

[pblanc]

I’m with Pblanc on the hull damage



I’d patch with S-glass, covered with release treated peel ply, both inside and out. That may also present aesthetic issues

An interior patch with a single layer of 6 ounce/square yard plain weave S fiberglass made over Kevlar can be very cosmetically acceptable. One layer of such cloth fully wetted out with the weave of the fabric filled with epoxy is very nearly transparent.

Below are some photos taken of the interior of a vintage Kevlar Curtiss Dragonfly. I stupidly managed to knock this boat off some sawhorses in a garage and it fell about 3 feet landing on its side on the concrete floor. The resulting sound was rather sickening but when I inspected the damage it was rather minimal. There was a small crack in the external gel coat and the type of "white line" Kevlar damage shown in the photos posted by the OP. Dave builds 'em tough.

The interior patch I applied is actually a two-layer patch but done with lighter 4 ounce/square yard S fiberglass. So for most of the patch you are looking through two layers of 4 ounce glass and one layer around the periphery.
Do you see the patch? Well it is a bit shaded. Here is a closeup:
Here is an extreme close up taken in bright sunlight, about as well as I can do with my Pixel phone:
The patch starts just above the shadow of the phone. You can make it out as the slightly lighter colored area in which the weave of the Kevlar is less apparent. Someone casually examining the interior of this boat would probably never notice it if they didn't know about it.

This is one reason I recommended using S fiberglass for both interior and exterior patches if the OP has to purchase fabric since the same cloth would do very admirably for both inside and outside. An aramid patch on the interior of a Kevlar boat sticks out like a sore thumb.

 

[Glenn MacGrady]

Halpc, when I had my split and rotted gunwale damage detailed and videoed above, I too received here contradictory suggestions -- everything from replacing the entire gunwales, to scarfing in segments, to debates over different types of glues to infuse.

As one with no woodworking shop, skills, tools or experience, and a small bank account, my philosophy was this: Try the easiest and most inexpensive solution first, which was to use proven G/Flex epoxy glue. Then, if that didn't work or hold up, I could remove the damaged section and go for a scarf or entire gunwale replacement.

My G/Flex infusion worked just fine and has held up for seven years. Admittedly, the section of gunwale I repaired was not supporting a seat hanger, but that wouldn't have changed my philosophical approach. In long retrospect, I think my G/Flexed section of gunwale is stronger than any of the original wood sections.

If your damaged sections are epoxy infusable and clampable without removing too much loose structural wood, if I were you -- which I'm not -- I would go with the same minimalist ("why not try it") philosophy, especially if you're not overly concerned with aesthetics.

 

[Guest]

I was looking at the long, relatively clean split on ALSG stripper’s inwale, and the equally straight forward rotted wood decay on your Wildfire, versus the variously directional splits and shattering on Halpc’s inwales and outwales.

While I agree that the simplest solution is often the best solution, those gunwale issues seem more complex to resolve satisfactorily epoxied and clamped in situ.

Never know ‘til you tried. And if failed, faced with removing the consequences. Folks who have tackled those kinds of gunwale splits and cracks, would you recommend epoxying the ‘wales left in place, or removing them before gluing back together?

Halpc, let us know how you decide to proceed, and when you do, photos please.

An interior patch with a single layer of 6 ounce/square yard plain weave S fiberglass made over Kevlar can be very cosmetically acceptable. One layer of such cloth fully wetted out with the weave of the fabric filled with epoxy is very nearly transparent.

Pete, I concur that an interior S-glass patch will essentially disappear. Patching the gel coated outside with glass and epoxy, not so much.

I’d want some epoxy and glass over those visibly broken frayed strands. Even skipping that and just picking out the loose material and filling with gel coat, meh, other that white-on-white I haven’t seen many gel coat repairs that really matched worth a dang, and I’m colorblind.