varnish and epoxy

was wondering about kevlar boats that have just epoxy over cloth (no gel coat). thats what it looks like to me. wenonah jensen comes to mind first. I put 5 coats of varnish on my wooden boats to protect the epoxy. what aboat epoxy on kevlar boats that doesn’t have some kind of gel coat on the outside?


Not epoxy
They are made with a different resin, a vinylester or polyester resin which is more resistant to UV breakdown than epoxy.

The kevlar itself WILL discolor over time with UV exposure though, even darkening noticably after a few hours in the sun and lightening up again when put inside. If you have a skin coat kevlar canoe you will notice lighter colored stripes where the straps held it to the roof rack if it’s on the car a while.

Over time it will show some brakdown, but not as rapidly as epoxy.

Varnishing a skin coat boat isn’t a totally terrible idea either, especially after it gets scratched up a bit. Makes it look shiny new too !

epoxy, vinylester, polyester
not the same.

Wenonah uses polyester resin
I’m repairing a damaged Wenonah Voyager (2001 model). I assumed they had moved to vinylester resin as some modern builders have. When the gel coat wouldn’t kick off over a epoxy repair I made I contacted Wenonah to ask what resin was used. They told me it was built with polyester resin.

For the record, since there has been a lot of complaints about canoe/kayak companies lately, Wenonah has been great with customer communication, information, and timely shipping of repair materials! Thanks, Tish.

Some builders have moved from polyester resin to vinylester resin. As noted, polyester and vinylester resins are less affected by UV than epoxy. Store your craft out of the sun and don’t leave it on the roof all summer and it will last many years. If your apprehensive about UV damage you can always varnish it with a varnish with UV inhibiters or buy a cover for transportation. I do see kevlar canoes on outside racks at outfitters and they seem to do fine for the year or three before they are sold.

I’m not an industry expert, but I’ve only read one company bragging about laminating with epoxy reson. The canoe I built in my basement with epoxy and fiberglass is painted, but that was to hide the cosmetic flaws resulting from my inexperience in construction, not for UV protection.


Not sure that polyester resin is UV safe
or less susceptible. I don’t even have DATA for vinylester, but based on apparent non-degradation of old vinylester boats I own, I think it does pretty well.

For flatwater boats, a UV resistant varnish is helpful, but I have not found a varnish that is hard enough and tenacious enough for whitewater boats. Welcome suggestions.

Vinyl Ester
Is a derivative of Epoxy & is superior to polyester for water resistance. Unfortunately any derivative of epoxy will have a question mark regarding the long term UV resistance.

I have three Wenonah ultralight

– Last Updated: Nov-27-07 6:40 AM EST –

canoes that just have the epoxy over the kevlar.
I used to wonder why when I repaired deep scratches with the two part epoxy that you get in Lowes why it would tend to peel off after a few years.
This year I did the entire bottom of my Jensen over and talked to the Wenonah people prior to it and they said to make sure I used the polyester resin, or it wouldn't take properly.

I disagree with some of the above posts that say the UV will darken the kevlar over time.
One of them is going on ten years, and stays on the roof of my truck for three months each winter down in Florida, and the color still looks like a new boat.
If you recall that new Jensen that you went over and looked at when we were at the Chatahootchie race, mine is the exact same color.



I not an expert, and it is presumptuous to tell you what resin your canoes are made with, but I’ve put my foot in my mouth before so here goes----


There are very few commercial canoe hulls laminated with epoxy resin. Movement is towards vinylester on more high tech and expensive layups, usually vacuum bagged or vacuum bagged and resin infused. Epoxy is used with wood strip and plywood hulls because it adheres better to wood. They are then varnished to protect the epoxy from UV. Older glassed wood canoes may have been fiber-glassed with polyester resin since it came into use decades earlier. It’s easy to tell when you try to remove the glass. Poly comes off easy while epoxy holds better and tends to tear up the wood surface somewhat in removal.


I don’t think Wenonah uses epoxy resin to make hulls. Few canoe/kayak makers do. I experienced curing and adhesion problems when I tried to use gel coat over a epoxy repair on a 2001 kevlar Voyager I’m repairing. I had presumed the canoe was made with vinylester resin. Called Wenonah and they said it was made with polyester resin. Their telling you to use polyester resin on bottom of your canoe leads me to believe that your canoes are constructed with polyester resin also.

Call them with your serial # and they can tell you what resin was used in that canoe. Type of resin used is important as I think there will be less potential compatibility issues if same resin is used for repairs (as in their telling you to use polyester).

I’m going to do some test panels to see if gel coat (polyester) can be made to work over epoxy in spite of my past failures. Two experienced and knowledgeable posters have assured me it can be done, so I’m going to test the process off the canoe.


I can only assume that mine are
polyester impregnated kevlar, since I did in fact call them prior to redoing the bottom of the Jensen and that is what they told me to use.



I do not know why polyester should not
Adhere to epoxy !!

crazy idea
why I was asking this question is that I have some forms from a solo canoe I built laing around.I been doing research where people make forms then lay kevlar over them to make a canoe. was planning on using about 10oz of kevlar then 4oz of S glass on the outside.( no pigment color just the yellow kevlar showing).then use foam in places to stiffen the inside and 4oz of cloth on the inside.was planning on using epoxy,but now after the answers I got will go with something else.


CBJ, did you finish the teardrop?

hey string
just about done with the teardrop. need to finish the inside and galley area.tring to come up with a winter project to stay maybe a composite boat this time??