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Permalink Reply by lhedrick on October 20, 2009 at 5:36pm

Karen,

Kevlar has different characteristics then fiberglass. Sandpaper will not cut it. It will just grind away the epoxy leaving fuzzy paint brush type fibers like you describe. That's part of the reason we use it. It can't be cut by sharp rocks like fiber glass. It is much stronger and resists abrasion.

One way to cut it down is with a high speed grinder with a 60 grit disk. I also build kayaks. Mine are build using 1/8 inch plywood. So you would need to be very careful when trying to grind it down or you will cut into the thin plywood. My recommendation would be to paint epoxy on the fuzz to get it back down in place. Carefully build it up with epoxy and wood flour. You might be able to cut it down a bit with a very sharp carbide scraper. If it is on a chine you could try to epoxy it then cover with plastic and tape it down or hold it in place with an pressure air bag or vacuum bag. Then build it up a bit to smooth it out. Light sand only and at the first sign of fuzz stop an epoxy it again.

If you have Kevlar cloth encapsulated in resin you can cut it with a new sharp utility blade. So, if you epoxy Kevar to a piece of plywood you can trim off the excess.

Just don't ever try to sand it.

Good luck
L

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Permalink Reply by Karen Edwards on October 21, 2009 at 2:02am

Thank you for your reply.

I am going to mull this over for a bit... I appreciate your advice and multiple suggestions very much.

Karen

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Permalink Reply by lhedrick on October 21, 2009 at 7:40am

Karen

Something I forgot to mention. Epoxy softens with heat. I have never tried this but with a heat gun you might be able to soften the epoxy enough to pull off the cloth. Maybe someone here might know if this is possible. If not then bonding some glass to scrap and doing a test would yield the answer. I would give it a try but my shop has been shut down so I don't have any place to build things right now.

In general when epoxy soaks into wood it really bonds well. I am sure most of us have the stories of gluing things to our work tables and braking them while trying to get them free.

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There has been a lot of discussion about Kevlar on Sandy's forum at montana-riverboats.com. Because of the problem you have run into Sandy and others are advocates for using Kevlar for structural support only on the inside of boats. Here is a link to a discussion we had in the last few weeks.

http://montana-riverboats.com/boat-building.php?forum=2009&mode=show_msg&msg=1531&start=0

It is my belief that Kevlar's properties are bet utilized on the outside. But, that's just my opinion. A sea kayak is a totally different deal. We don't really face having a sea kayak get pounded on rocks the same way a dory does so, Kevlar might be overkill on a kayak. My kayaks only use light 6 ounce glass cloth and tape.

L

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Permalink Reply by Karen Edwards on October 21, 2009 at 12:44pm

Thanks for the link. I will check it out. Iove your idea of warming up the kevlar! I will heat up the strip right now!

As for the kevlar, I wanted it because the boat is 18' long. I have already dropped it while trying to get it up against a tree for an end pour! I know I am hard on things so, yes, it is probably overkill but I have had plastic kayaks before this one and they got the crap beat out of them. I know I beach them hard and sometimes drag them when I am lazy. Perhaps I won't do this with my wooden kayak since it is taking so much time for me to finish but who know after a week of paddling if I will care :)

Thanks again!

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