Repairing Creases in Royalex

TL;DR - Old WW Tripper in Royalex has extensive creasing from being pinned. Hoping to build confidence in repair method before starting.


I am new to this community, but I have been reading many of the existing threads on repairing Royalex as I prepare to attempt my own repairs.

I have a well-used 1987 Old Town Tripper in Royalex that I just purchased. I don’t mind a cosmetically beat-up boat, since I will mostly be using it for a yearly trip down the Flambeau river in northern WI (read: bouncing and scraping off some rocks). I’ll also be puttering around flatter waters the rest of the year.

The boat looks like it was pinned on the right side near the portage yoke at one point. There is a set of creases that are mostly under the vinyl layer, except for one area where it looks like at least the outer layer of ABS is cracked as well. I have an album of the pictures, not sure if I am allowed to post links yet:

My main plan so far is to gutter out the area of the hole and fill with thickened G-Flex, then apply a Dynel patch over that area on the outside. Should I back that up with S-glass on the inside for structure? Or use S-glass on the outside, with Dynel on top?

The extent of the creases concerns me, however. They don’t feel softer than the surrounding areas. Based on what I’ve read, the inner foam core is probably crushed in there, so I am wondering if I should be opening up the vinyl on these creases and attempting to fill them with G-Flex as well. Should I consider a fiberglass/Dynel patch over the entire area to take the stress off the network of creases?

I have read several opinions stating that some creases are normal and to be expected with a canoe in WW use. I consider myself a decent paddler and have not pinned any of the livery boats I’ve used on the Flambeau river over the last 10 years. I don’t expect to stress this area in the same way as it was before, but Murphy’s Law will probably take me to task for saying that.

Lastly, there are a few round holes as well as gouges and scratches that only appear to be in the vinyl. Can those just be filled with thickened G-Flex and painted?

Thanks for your time, I realize this is a long post.

Sometimes you can detect a crack in the ABS material underneath intact vinyl by pressing in on the hull but sometimes you can’t. I have quite a few times found cracks in the solid layers of ABS beneath vinyl that was pleated but not broken. Or found extensive cracks in the ABS beneath vinyl that had only a short, small slit.

I wouldn’t worry about creases unless you think that the ABS structural material is actually cracked. But to determine whether or not it is you are going to have to remove the vinyl off the interior and exterior of the areas that appear to be most damaged. If you don’t find cracks in the ABS in these areas, you probably won’t find them in areas that seem to have suffered less stress. A lot of times by just looking at the pattern of damage and imagining the exact nature of the mechanism that caused that damage, you can make a good guess as to where cracks are most likely to have occurred.

If you find cracks in the ABS in either the interior or exterior solid lamina of ABS or both, I would patch the areas overlapping undamaged hull by at least 2 inches in all directions. If you can, take the vinyl off first. If the hull is cracked all the way through, I would apply patches internally and externally. I might even do that if the hull is only cracked on one side since it is nearly impossible to crack on solid layer of ABS without also cracking the foam core. Yes, go ahead and gutter out the cracks and fill them in with G Flex epoxy. I usually thicken the epoxy a little with cab-o-sil (colloidal silica powder). For patches I would prefer S fiberglass externally and aramid cloth internally although you could certainly go with S 'glass inside and out or S 'glass on the inside and Dynel on the outside. Dynel may have better abrasion resistance than S fiberglass, but I believe that S 'glass imparts greater structural strength which is what you are after when repairing a crack.

I did a fairly extensive repair of a Royalex canoe that had also been pinned one or more times and have an album of the repair. If you click on the individual photos in the album, you will find a caption that might be helpful. If you have any questions, come back and post them here:


Thanks for the reply. I found your album while searching previously, and it has a lot of great pictures and advice. Thank you for putting that out there. I have the G-flex kit on order that comes with silica for thickening. I’ll start taking off the vinyl in the creases and look at what’s going on underneath.

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