I just purchased a 1990’s vintage Wenonah Itasca Kevlar 49, very reasonable price because of its weathered condition. The Itasca has the standard Kevlar 49 equipment meaning a skin-coat and wood gunwales. The boat has been sitting upside down on saw horses, uncovered, on the north side of a building for a long time, so long that the outwales have rotted from exposure to rain and dew. The inwales and decks look solid with the quick inspection I made. The hull looks in good shape except the skin coat finish seems to be missing off the bottom of the hull like the exposure to weather wore it off. I can feel the smooth skin coat on the tumblehome sides that were probably most protected from the weather but as I run my hand around to the bottom of the hull I can feel the texture of the Kevlar fabric. I’ve read where Kevlar can rot with exposure but I didn’t see or feel that condition, just no skin coat. Where the Kevlar fabric texture is exposed (everywhere except the tumblehomed areas)in areas between the ribs, the hull is a little spongy. I seems that in those areas the hull is missing the rigidity provided by the skin-coat.
Any suggestions here? Replacing the outwales and refinishing the woodwork is no problem, in fact a welcomed project. I built a cedar strip canoe last year so I’m familiar with two part epoxies.
Thanks.
It is a simple process to recoat (epoxy)
the whole bottom. I have done several.
Use West systems 105A resin and 207 Epoxy.
Call them up and they will walk you through the process, and send you all the info you need
jack L
Another question
Do I need to be concerned with what Wenonah used to layup the hull? I’ve read about possible incompatability of different coatings.
Also, how would you prep the hull? I don’t dare sand because I think I would immediately raise fuzz. I would guess clean all the dirt and contaminants from the surface, maybe some bleach or vinegar to bleach out any stains, another wash, a wipedown with MEK or acetone and then a two part epoxy.
Thanks.
actually
you want the fuzz. this helps the epoxy bond to the fibers. The new epoxy layer will provide you good protection for the fibers BUT epoxy without a UV barrier will not last long. Not sure what folks are using to maintain a clear coat, maybe varnish, but the epoxy repairs I have done got painted.
btw- the new skin will up your boats weight considerably.
good luck. sounds like fun… 
steve
Two points. Exposure doesn’t make
a Kevlar laminate “spongy.” The same mechanical abuse that removed the skin coat makes the laminate softer.
Second, skin coat contributes even less to hull rigidity than gelcoat.
Wenonah’s canoes would stay stiffer, longer, if they used one or two layers of S-glass or E-glass for the outer layer, rather than Kevlar. Kevlar is not an “outside” cloth.
Flatpick is correct that the slight fuzziness of Kevlar aids adherence of a new skincoat made of epoxy. Unless there are lumps or fiber clots, sanding isn’t worth it. The fuzzies on my one boat with Kevlar as the outside layer were so long that I used a propane torch to burn the fibers down to nubs so I could get them off with a razor. But you shouldn’t need to worry about removal.
I’ve re-skinned two boats with West Epoxy. The 207 hardener would be best because it has a UV inhibitor and has less of a tendency for amine blush to rise to the surface. One rolls on the epoxy, and then when the first coat is getting close to hard, one rolls on the next coat before rising amine blush interferes with the first. I’d estimate about four layers, not more, or the surface may be a bit brittle.
I wonder whether a quality 2-part marine urethane varnish, in several coats, would not be an alternative. Trouble with epoxy is, it is not self-leveling like varnish, so after getting several layers rolled on, one has an orange-peel surface that must be leveled with a random orbit sander. Carefully.
A screwball idea. Bias-cut 4 oz carbon cloth and epoxy it on over the worn area. It will stiffen the hull without adding much more weight than several coats of epoxy. And the carbon will provide a slippery wear surface.
Please, don’t anyone bring up Dynel. Soaks up resin, and isn’t nearly as strong as S-glass or carbon.
Yet another question
I made a cedar strip canoe last year and I used the West Systems epoxy, the one already mentioned here. I don’t want to heavy up the light-weight hull too much so I’m not sure I want to overfill the exposed weave.
I’ve taken the outwales off. They came off in pieces because they’re so rotten. The inwales are glued to the hull and they look grey but in good shape.
What about this plan?
Scrub the outter hull with TSP.
Use a bleaching agent like vinegar or bleach to remove any stains.
Wash again with TSP.
Rough up with obital sander (what grit)?
Wipe down with tack cloths and acetone.
Apply one rolled on layer of West Systems epoxy (I have leftover from my cedar strip).
Wash off the epoxy blush.
Apply Coats of spar varnish for UV and to finish.
The aluminum seat frame structure shows a little white rust. What’s a good treatment?
Any advice on removing the Wenonah decals? I’m guessing Wenonah will sell me replacements.
Thanks for the great advice.
Sounds plausible. Be prepared to do
a second layer of epoxy over the still-clearcoated parts of the hull just in case it takes that to give you sanding margin to level the surface. But remember that if the hull is in the sun much (while cartopping), you may end up topping it with a UV resistant spar varnish.
IMHO if your going to go through
the trouble of sanding the whole thing down ... Mo' betta' to lay another ply of e or s glass down THEN work on finish ...You have an even, consistant surface, pretty much elimintaed all the problems of wetting out, then atempting to sand smooth the kevlar thin > thick-er skin coat sections AND the hull is gonna be stiffer once again ... Could even beef up selected spot then 'consolidate' the whole thing with a final play of 4 ounce or something light ... This also has a very smooth weave if you chose to fill it.
I’d do that on the worn bottom, but
glassing the whole boat will add more weight than I would care for. That’s why I suggested carbon. Doesn’t resist wear as well, but much lighter.
Itasca outer hull restoration
I completed the Itasca restoration. The procedure and results went like this:
I called Wenonah and got the advice to use polyester resin rather than epoxy. I spent quite a bit of effort cleaning and removing the black mold from the bottom of the hull. I prep sanded the hull using 100 grit paper on my random obital sander avoiding the decals and hand sanded the leading edge of the stems. It turned out that the Kevlar 49 decal was not available from Wenonah. I wiped down the hull with acetone on a rag as a final prep for the polyester resin coating.
I applied the polyester resin with a four inch, short nap roller. I cut some s-glass strips and applied a couple to each stem along with the coating of resin. I lightly sanded the cured polyester resin with 100 grit paper on my random obital sander. I followed with a brushed-on coat of semi-gloss spar varnish.
The first coat of spar varnish is curing right now and I haven’t yet decided if I’ll add a second coat. The spar varnish tends to fill and has produced a relatively smooth finish.
Now to install the replacement outwales. The outwales are scarf-joined pieces of ash. I plan to use boiling water to help form the outwales around the outer hull.
Thanks for all the suggestions.