I want to attach velcro (or other hook-and-loop fabric) to Kevlar and carbon fiber (vinylester resin). Any thoughts on the right adhesive?
I’ve tried Velcro brand sticky-backed cloth, the “heavy-duty adhesive” option, and it didn’t work out well. When I tried to unstick the two pieces, they stuck to each other more strongly then they stuck to the Kevlar or carbon. Worse, and more precisely, the adhesive itself (a clear, rubbery material) stuck to the Kevlar or carbon, but the fabric detached from its own adhesive backing. I ended up with adhesive alone on one piece of carbon/Kevlar, and adhesive plus one side of the velcro plus the other side of velcro, no longer sticky, on the other piece of carbon/Kevlar. So the real problem is that the adhesive supplied by Velcro doesn’t bond strongly enough to Velcro’s own fabric. You would think this would cause failure in all applications, so maybe the fact that the velcro gets wet is part of the problem.
The fabric that carries the hooks and loops appears to be a mesh made of hard plastic, in a gauge small enough that the overall cloth is flexible. Because it’s mesh, one of my worries is that any adhesive I use will bleed through the fabric and gum up the hooks and loops. My best thought so far is to use a very thin coat of epoxy on the carbon/Kevlar, just deep enough to sink the plastic mesh into but not deep enough to submerge the hooks or loops.
The application, to give the big picture: I have a new Placid Boatworks RapidFire canoe, which is designed to be paddled kayak-style from a seat attached to the bottom. But I prefer to kneel or sit on a high seat most of the time, so I ordered it with a cane canoe seat in addition to the kayak seat. I want to be able to switch back and forth, and my idea for a removable installation of the kayak seat (which is made of carbon) is to velcro it to the bottom of the hull (which is made of Kevlar).
I am not committed to a hook-and-loop solution. Any think-outside-the-box solution to the problem of temporarily, but securely, attaching a carbon kayak seat to a Kevlar hull is welcome.
– Mark
Mark, Is the bottom of the canoe
smooth or can you still feel some texture form the weave ? Even the H.D. stuff needs a smooth surface …
Suggestion if not smooth … tape off area where you want the velcro … brush on a tiny bit of epoxy and lay over a smooth piece of 4/6 mil clear plastic and smooth out all air w/ squeegee pulling tape and plastic after epoxy kicks in but not fully cured so everythig is nice and neat. … let cure to have a perfectly smooth surface to stick Velcro to.
Now stick the harder ‘hooks’ side down in the full range you wish to have for the seat on the hull … on the seat side ( also must be smooth ) use only tiny patches of the ‘loops’. Just enough to hold the seat(s) in place ( about 8 square inches is more than enough) is all you need … Now the loops will let go without pulling up all the hooks.
It won’t work long-term
You can glue in the Velcro with contact cement, but if you’re going to be pulling the seat out on a regular basis, the Velcro won’t hold for long. As you discovered, the hook side is a plastic that’s very difficult to glue to anything (I think it’s polyethylene) and the factory goo doesn’t last in a wet environment (it’s even worse when it’s cold out). I wish I had a better solution for you, but without seeing the setup involved, I can’t help you.
I agree with Bynstrom
I’ve been using Velcro Industrial strength to hold in my white water pedestal and knee pads so I can remove them when I switch to bench seat. I can get about three removals before I have to replace the Velcro. I used the pedestal only all last summer and it didn’t come loose, but after I’d move it twice the velcro pulled off the hull and the minicell. Last week I tried the white velcro with “Waterproof glue” and it lasted only one day. It seems to help is to install the new velcro and let it sit with weight on it for about a week, then use it. Seems to last longer and hold better this way.
I wish I could find out
what someone used to secure strips of the hook side on the bottom of my carbon boat - I wanted to remove it and had to pull with pliers and cut at the adhesive with a knife (like skinning) to get it out!
Has to be super smooth and clean.
Trick is to rub / roll velcro in place and do this real hard along the perimeter. Have some in one of our demo boats for 5 years now for seat adjust … very edges just starting to curl up.
Why not
sew the velcro to some heavy urethane backed nylon and then contact cement the urethane side of the nylon to the boat?