Mad River Royalex Cold Cracks

I have a Mad River Royalex canoe with wood trim that last winter split in two places due to the cold. Both splits are clean and about a foot long. I have seen West Marine G Flex used by itself after the cracks were widened out and beveled. I also have seen royalex repair kits with epoxy and fiberglass cloth used. I would rather use the g flex as it looks better. Any ideas appreciated and yes the cold cracks will happen so be careful. Thanks

If yours is used in non-whitewater
applications, I would follow the West G-flex repair technique.

If I were repairing one of my Royalex ww canoes that had split down the side that way, I might do the G-flex approach, and then back it up with reinforcing inside and outside layers of cloth and epoxy.

A compromise might be to reinforce inside where it isn’t visible to photographers.

Let us know what you think about the possible need for cloth reinforcement. Probably you can get away without it.

What is the year, and model of the Mad River canoe?

How long have you had it, and where is it stored in winter?


The idea is Mad River will not warrenty cold cracks no matter what. So unless you buy one from LL Beans you are one your own to fix it. The screws on mine were loosened and it was in a cold area and it cracked. Anyone could sue them for implied warrenty depending on your State in small claims court.

Some have tried to forestall cold cracks
by widening the holes in the Royalex through which the screws pass. Seems logical, though I’d still loosen the screws toward the bow and stern for winter storage.

There’s a curious variability in who gets cold cracks and who does not. One factor that has not been considered is that cold cracks might get started when the ends of the canoe get thumped hard on ledges and rocks. Small cracks created this way could spread into foot long cracks when very cold weather causes the Royalex hull to contract while the wooden gunwales cannot.

This is the first I have ever heard
of a royalex boat with wood trim developing those cold cracks when the wood trim was loosened for the winter. Pretty wierd. On the other hand you could just think of it as a badge of honor for your boat. I have a Tripper that is VERY old that had wood trim and it has the cracks. Old town actually sent me a replacement boat in exchange for the serial number cut out of the old hull. I now have both boats. My favorite is the old cracked one.

Just finished repairing 3 cracks in my Mad River Explorer. 2 of them, about 3 to 3 1/2 inches in the Bow and 1 about 4 inches in the Stern. I used the G-flex and it looks pretty good, just needs some sanding. My question is if the Gunwales are supposed to be treated with gunwale oil why didn’t they oil the inside of the inwale and outwale from the factory? They looked good on the outside and I applied Watco finish after every season. When I removed about 10 screws from both sides and both ends it looks like they were never oiled at all or sanded very well. I bought it new and have never taken more than the 4 or 5 screws recommended out. Sure appears to me the side next to the canoe never saw oil. I always made sure it was dry when I put it up and it was kept in a unheated garage (in Montana) for years with no problem. Think I should remove the ash gunwales and soak the crap out of them? Maybe enlarge the screw holes some as well?

It isn’t just Mad River. A lot, if not most canoe makers fail to treat the hidden faces of the inwales and outwales. The same is often true of the cut ends of thwarts, seat frames, and yokes. These areas are especially important to treat because the end grain is exposed, and ash loves to soak up water along the grain. The exposed wood in the holes drilled in the gunwales, thwarts, and yokes for the attachment machine screws is almost never treated either.

Not a bad idea to remove the yokes, thwarts, seats and gunwales and treat these surfaces. A pipe cleaner works well to apply finish in the screw holes. You can ovalize the screw holes in the hull somewhat in a fore and aft fashion, especially those near the stems, where cold cracks are most likely to occur.

Instead of oil, varnish, or urethane I now treat the hidden faces of the inwales and outwales with a low viscosity epoxy which has better staying power than any of the above. But if you want an oil finish on the exposed surfaces of the gunwales, you need to keep the epoxy off those areas as it will prevent the wood from taking up the oil and the finish will be somewhat uneven.

There’s a ton of variability in what boats crack and which don’t (or haven’t yet). It’s often said that aluminum/vinyl gunneled boats don’t crack, which is patently false. I have seen many crack. This doen’t jive with MR’s party line stance on wood vs Royalex expansion… I don’t think they ever really had a firm grasp on what was going on.
I have an old Courier which (knock on wood) doesn’t get cold cracks even without loosening the screws… stored under a tarp outside. Ditto a friend of mine with an old mystery model MR. He bought a cream puff Revelation however that cracked the first winter he stored it outside… and cracked again the next winter. Revelations seem especially crack prone. I’ve taken a few apart and the hulls are under tremendous strain by the wood. No wonder they crack.
It’s really an irksome and imo lame situation. The untreated faces of gunnels and often hideous construction only make it worse.

I agree that there is much more to cold cracks than can be explained solely on the basis of differential expansion. On the other hand, if one removes the gunwales, ovalizing the screw holes in the hull to relieve or reduce stress on wooden gunwales can do no harm.

There was a lot of variation in Royalex over the years and between different manufacturers who speced sheet very differently, even if it was all made in the same plant in Warsaw, IN.

I wonder if just taking out the yokes and seats and maybe the deck plates would be enough. The boat could then expand and contract as need be. Who knows.

I had a cracked gunnel for quite a while, and it was an eye opener how much the crack opened up/closed just with humidity changes much less big temp differentials… much more than the aggregate amount gained by drilling out the holes, unless you went way bigger. But as said doesn’t really hurt… makes the gunnel fitup and little less perfect, and the boat a bit more noisy.

The amount to which Royalex hulls expand and contract with temperature changes is quite impressive. A couple of times I tried to outfit Royalex whitewater boats with foam pedestals and thwarts glued to the top of the backrest portion of the pedestal. That always failed because when the hull expanded, the pedestal would drop up to a half inch below the level of the thwart.

Instead, a attached vertical dowel segments to the undersides of the thwart which rode up and down inside of lengths of PVC pipe pressed into the top of the minicell pedestals.

I sold and lived with several royalex explorers. I found ovaling the holes in the royalex to be effective down to ten below. That was about 8 screws back from each end and drilling out the hole in the royalex at least 3/8" toward the ends of the canoe. At -30 you need to slot all but the center screw and think 1/2" clearance for the plastic to shrink. That was thirty years ago in at least two different formulations of royalex. After a couple of bad experiences I just did the ovaling on all the wood trimmed royalex boats I sold as dealer prep. I also learned to always get webbed seats.