Kevlar J180 Repair and Maintenance

Hi All,

I just recently bought an old Wenonah Kevlar J180 C1 in need of a little TLC. I plan on using it as a fun trainer and an introduction into the “racing” class on some of the flatwater races we have here in Maine (I’m a Royalex rec-class fellow, thus far). Anyhow, with it’s age, the hull seems a little brittle, and has a few cracks here and there. No jagged gashes or holes, but just some clean cracks. Additionally… to my shame in the first day in my possession it acquired some pressure cracks in several of the foam/kevlar ribs on the drive home on I95 from a nasty cross wind. The shape is still maintained just fine, but the ribs obviously flex more readily (and unnaturally!) at those cracks now.

First, I don’t really care about the oz difference between Kevlar and fiberglass, so could I effectively repair this boat with fiberglass? I do care about strength, and the compatibility of the two materials together…but I am kind of cheap.

Second, can I effectively re-inforce the “tired” ribs by overlaying each with a few layers of glass/kevlar?

Finally, the outside of the hull seems like it could use a general “refreshing” of it’s epoxy coat - would that be madness to coat the outside of the hull in a thin layer of epoxy, or beneficial?

Any opinion(s)and advice would be greatly appreciated!Thanks so much!


Last year, I just refinished a J-200

– Last Updated: Apr-25-11 5:50 AM EST –

that was probably in worse shape than yours, and yes you can use fiberglass on the kevlar.
I do all the time on our comp Cruiser and our Jensen 17.
Do the patching on the inside of the boat over the ribs. Make sure the area is clean, and then roughen it with sand paper. Wet out the fiberglass with epoxy and lay it over the cracks making sure the patch not only covers the crack, but goes over the rounded part of each side. While the patch is still wet, cover it with a stiff piece of clear plastic film, like a notebook page ptotector, and tape it down as tight as you can get it with duct tape. A day later, take off the duct tape and film, and you will have a nice smooth patch. You might want to do a second and possibly even a third coat of epoxy over the patch after each one is hardened, but make sure you sand each one lightly and use the plastic film with each.

On the Bottom use the West Systems two part Epoxy, and do the whole bottom. Sand the whole thing lightly, (making sure not to sand into the kevlar).
Tape a line with newspaper at the water line, or where you want to stop the epoxy, so it won't run and make ugly drippings on the rest of the boat, and give it a light coat. I find it is better to give it several light coats, rather than one heavy one.
Get the quart of Resin and the pint of hardener and their pumps and there is enough for about three canoe bottoms to be done.
It is not a hard job, and you'll end up with a like new boat

jack L

Peel Ply makes a far nicer
patch rather than a plastic notebook sheet. Allows you get fair edges.

RE: J180 - Thanks
Thanks Jack!

I was so mad, cursing (NOT cruising, cursing) my way down the highway after I saw that I had damaged the ribs. I’m glad to know she’ll be alright.

For epoxy-ing the hull - does one generally only worry about doing it below the waterline? I had seen one method of using a credit card (a friend’s or roommate’s of course) or scraper to get a really thin coat of epoxy down. Have you used a similar method? I’m excited for a new little project.

Thank you again for your advice.


Oops, I almost forgot
On the West Systems, for the entire bottom and or the sides, use 105-A resin and 207-SA hardener.

Sure you can do the whole boat.

The best part of the 105 and 207, is that there is a long working time, and you can even give it another coat while it is still wet. It takes several hours or more before it is even tacky. Once it is tacky I found it is best to wait till overnight and then when it is hard, sand lightly and give it a second coat.

The secret to it not running is very thin coats.

I put mine on with a throw away paint brush, (about a two inch brush) and then rolled it with a throw away roller. Make sure the roller has a very fine nap. You can get them at Lowes.

I just used the roller to spread any that was too thick, and almost didn’t need it.

For the patches I use the much qucker hardner and just mix up small batches.

The West systems materials and pumps will set you back some bucks, but once you have the pumps they are good for a long time and there is no cleaning them out.

Hopefully some of the pro boat builders will correct any thing that I said wrong, or will add their knowledger here.

Jack L

West describes the process of
applying epoxy on their website. They recommend, and offer, thin foam rollers for the procedure. I used them, and it went OK. Jack is right about using the 207 hardener. Don’t do too many coats, just enough that you have some “meat” to sand afterward.

On glassing inside, if you have to glass over convex and concave rib surfaces, you may want to cut “on the bias” so that the cloth fiber direction is at about 45 degrees to the rib edges. This will help the cloth conform better.

Ideally, Kevlar would be better for inside patching, but 6 oz glass is ok. Go to and see what cloths they offer. Kevlar, graphite, and polyester cloths are much lighter than glass, but that becomes a consideration only if one is using a lot of cloth.

Call Wenonah
I recently refurnished an Ulta-Light Itasca. I posted here for help and also called Wenonah. They were VERY helpful.

I found that Wenonah used polyester resin on the Itasca, not epoxy. I rolled on a coat of polyester resin and layed on a couple of s-glass strips over the leading edges of the stems. I followed up with spar varnish for UV protection. Spar varnish is self-leveling producing a smooth enough finish.

You can use West Systems Epoxy over the polyester resin that Wenonah uses but I followed Wenonah’s recommendation and used polyester resin.

Especially on lightweight hulls it’s possible to redistribute weight with repair materials enough to unbalance the hull (a caution from Wenonah).

Hope this helps.

Question them closely next time.
I suspect their “polyester” is actually vinylester, which is stronger and more resistant to micro-degradation by water.

Perhaps it’s understandable that West recommends their epoxy to recoat powerboats that have hydrolysis blisters due to micro-infiltration. But their data and other data I have seen indicates that good epoxy is somewhat superior to vinylester, and much superior to polyester.

Others mentioned the UV protection
and that is a good point.

I don’t like to add weight, so I don’t use anything over the hull after it is done, but the boat should either be stored in doors or covered if stored out doors.

jack L

Vinylester vs Epoxy

– Last Updated: Apr-25-11 4:56 PM EST –

Thanks everyone!
I did just call Wenonah, and they said the same as indicated above about using the original vinylester. Their reasoning was that vinylester resin can't be layered over epoxy in future repairs (although, the reverse is fine). However, if West System epoxy would yield a stronger, more durable result, I don't really care that I can't then use vinylester over it in the future. West says their epoxy basically kicks poly/vinylester butt, but... that's their site. For this particular application, does it really matter? I think I may just go with epoxy...

I have done two Wenonah boats
with West Systems and it has done just fine

jack L

Wenonah told me to use polyester resin
from the auto repair section of any hardware store, even though everyone here advised to use vinylester.

Go figure.

I sold the boat before trying their advice, so I don’t have any experience with the actual refinishing using their instructions.