Stress Crack

I’ve been looking at high end solo canoes (black gold bells, placids, swifts) and have recently come across one that is in excellent condition expect for about a 2 inch stress crack in the side of the hull.



My first question is the stress crack something that should keep you from purchasing the canoe? It looks like it hasn’t torn the fabric and I think it could easily be repaired just by putting a patch over it but I’m no expert on composite repair.



Second is how much does the stress crack affect the value? I’ve seen similar like new canoes without a crack in the $1800-$2000 range in my area and would like to get an idea of a fair price with the crack.

Stress Cracks
Stress cracks are just that - a line of shattered resin where the fabric has nor broken. The usual patch is a matching piece of, usually Kevlar, peel plied down to flatten the patch’s edges and to match interior texture. There is no significant weight disadvantage and no compromised strength.



An array of Bells, Swifts, etc in the $2000 range are, depending on laminate and trim, roughly 1/3 off already. I suspect discount for a well patched stress fracture is just another factor in the mix of trim material, condition and general hull condition. Same goes for Colden, Hemlock and any other high end composite hull.

CE Wilson is clear about patching inside
where a Kevlar patch will match the Kevlar inside the hull. But you aren’t clear about where the “stress crack” is visible. I suspect you mean it is on the outside surface, not the inside. But what do you mean?



What boat and layup is it? Blackgold?



If the “crack” were inside, it would be seen as a distressed line in the Kevlar. If outside, it might be more a crack in the thin, clear resin covering the carbon, glass, or whatever they used for the outside layer. A crack in gelcoat or resin can often be ignored. But if I were patching outside, I would use glass, not Kevlar. Glass wets out clear, sands without fuzzing, easier to protect with a bit of spar varnish, or paint if you were dealing with colored gelcoat.

It is both.
The gel is cracked on the outside and there is a white line visible on the inside of the hull. There is also a small circular area at one end of the crack where the kevlar interior appears noticeably lighter in color than the surrounding area - not sure what that is though.

Since you probably won’t use the boat
on whitewater, your patch may not come under high stress, and I think you can follow CE’s suggestion about a layer of Kevlar inside. Use a thin epoxy resin like West, unless you have a local supplier of vinylester resin like that used by Bell. Epoxy actually works just fine, and it keeps in its containers until you need it again.



If you do just a layer, oval the Kevlar and cut for at least a 1" margin. I’m not sure I would do an outside patch, but a layer of glass would wet out clear.



It’s hard to speculate on what caused the crack. Rather than a point blow to the outside, sometimes the hull is bent from below, folded toward closed on the inside. Kevlar doesn’t deal as well with that as it does with outside blows. The folding would crimp the Kevlar inside and compression-crack the clear topcoat outside.