When you hear a big crack it is probably not good news

Three-years ago I lucked out and was able to purchase a 20-year old Mad River Outrage in like-new condition – it had really never really been paddled. For the past few years, I have been beating away at it like a class II paddler does when he gets in a little over his head. Lets just say the boat has a lot more scratches now than it did when I bought it.

This weekend I did the class II run at Otter Brook near Keene, NH. It’s a narrow, dam-release river where you spend most of your time dodging rocks. The only class II+ rapid is a two foot ledge that is usually run through a shoot on the right. This weekend that shoot was blocked by a strainer, so the options were portage or run the ledge. I ran the ledge.


I actually ran it twice and heard a cracking sound from under the boat both times. I didn’t think too much of it at the time, but when I dumped out the boat at the take-out I noticed a 3-inch crack on the bottom under the pedestal.

Crack in my boat form running the ledge

I guess even unused 20-year old Royalex is still 20-year old Royalex. It’s not bad now, I know it will get worse. Gorilla Tape will get me through the rest of the season, but at some point I will need to do a more permanent repair. I hate the thought of putting fiberglass on the bottom, but that is probably the fix, right? Is there a way to do it so it lasts? Any other options?

I have repaired quite a few Royalex canoes. Some repairs were relatively simple. Others were quite involved. Done properly, Royalex repairs can be durable. But the worst thing to do is to try some half-arsed repair with some type of goop. Applying tape is OK for a quick fix but using any type of resin not suited for the repair will make an eventual proper repair much harder.

Cracks under the pedestal are quite common. They most often occur near the front edge of the pedestal. The reason is simple. All your weight on the pedestal creates a stress riser where the relatively immobile portion of the hull under the pedestal meets the much more flexible portion of the hull in front of the pedestal.

There is almost certainly cracks in the interior solid lamina of ABS under the pedestal. To repair that you will need to remove the pedestal and the vinyl layer over and immediately surrounding the visible small tears in the vinyl layer. The cracks in the ABS structural layers are often considerably worse than the damage to the vinyl would suggest. The vinyl is much more elastic than the ABS and will stretch when the ABS cracks. If the interior cracks are not addressed, water can percolate down through the crack in the ABS and foam core and eventually cause the outer ABS solid layer to delaminate from the foam core. The sooner you address the damage, the less deterioration of the foam core you will need to deal with.

I sent you a PM with a link to a photo album I created when I repaired an old Mohawk XL13 Royalex canoe a couple of years ago that had cracks under the pedestal that were neglected and eventually led to the type of damage I just described.

Thanks Peter - appreciate the PM with the links to repairs. You are correct that there is a matching crack in the inside of the boat just in front of the pedestal. Tracing the line underneath I can tell that the crack does go under the right front corner of the pedestal.

Crack on inside of boat

This boat was outfitted using fiberglass on the strap anchors. You can see the crack going along the edge of the fiberglass anchor. You get a better sense of the outfitting here.

Mad River Outrage

Its definitely a bigger job than I thought. I really hate the prospect of taking everything apart, but I guess that is what I will have to do. I love the boat, and I’ll have a hard time finding another one to replace it.

Thanks again.

Looks like someone did a nice job with the outfitting. Yes, the fabric covering the ends of the 'glassed -in strap anchors also creates a stress riser at its edge. That probably won’t cause the boat to crack there, but a crack, once initiated, often follows the path of least resistance which would be the Royalex not covered by the patch.

Unfortunately, there really is no way to prevent stress risers when patching or installing outfitting. G Flex epoxy when cured, more closely matches the compliance of the Royalex itself and also has better elongation properties than conventional epoxy and especially polyester resin. That makes it a bit more elastic. When using a multi-layer patch, always make the second patch concentrically smaller (or larger) than the previous one so as to diffuse out the stress riser created by the patch as much as possible.

You definitely have a through-and-through crack. I would limit paddling the boat much until it is repaired as water will inevitably get into the boat and then into the foam core through the interior crack which you will not be able to completely seal off with tape. When filling cracks I like to thicken the G Flex epoxy a bit with silica powder. When patching over cracks I try to make the largest patch (if more than one ply) extend at least 2 inches beyond the sides and ends of the crack to overlap non-compromised hull.