Bonding UHMV to wood/epoxy Boat Hull

[Walt Nagel]

I am building a whitewater drift boat. I need to bond large sheets
of 3/16 UHMW to the bottom of a whitewater drift boat I am building.
The bond needs to be strong to withstand impact (from rocks) and of
course, waterproof. The UMHW would be bonding to a
wood/epoxy/fiberglass/kevlar/ bottom. Does anyone know of an adhesive that will work for this application?
Would it be difficult to do? Also, there might be a seam or two
with the sheets being butted together. What would you recommend for this application? I might add that the hull is already waterproof. So, the
purpose of the UMHW is for impact protection only. I hope one of you can
help. Thanks

[Jim Becker]

I am thinking that you'll be limited to screws to bond that material to anything else, but check http://thistothat.com to see what they say...

[John Bush]

Hi Walt,
I bought some 1/4" UHMW to face a set of croquet mallets I made. I bought it from a commercial plastics supplier that handles everything from aviation, biomedical, marine, to etc, etc. I chatted with the sales guy and asked the same ??. He said there is no adhesive that can give a permanent bond to the super slippery, quark size spaces between the molecules, tough as nails UHMW. I ended up drilling small countersunk holes and screwing it to the mallet head. Seemed to work OK and we will see how it holds up with that rough and tumble croquet crowd. At 1/4" thickness the stuff is kind if heavy as well, but they did have some 1/8" sheets that would be, amazingly, half the weight. Most of the drift boats I have seen out here(Steelhead and Salmon fishing) have a few extra layers of fiberglass mat and resin to help strengthen the hull and handle the occasional rock and sandbar. If it gets too traumatized they just sand it a bit and add new glass. A friend built a beautiful cedar kayak and covered the keel the same way.
Good luck John.

[Lee Schierer]

There are bonding agents for UHMW. I have a sample out i my shop that has fiberglass embedded in it, so epoxy would work. Check out his link. Garland Mfg These folks know UHMW. I also have some UHMW tape that has sticky adhesive back. I've had pieces in place for years and the adhesive is still working. When you peel of the4 uhmw the adhesive stays with the UHMW not on the substrate.

[Cliff Rohrabacher]

Lee has it right. YA gotta prep the surface before you apply the sticky tape. Foam core DBBL stick adheres about the best cause the foam core accommodates for all the little irregularities in the surfaces.

Prep by flashing the oils off with a propane torch or a Naptha wipe.

[Kent Parker]

Walt,

3M makes a product that might work. Its a polyurethane adhesive sealant called 5200. It comes in a tube. Typically, anything bedded with it can never be taken apart so keep that in mind. Also, if your plastic has any curvature and would have to be bent in place, allow adequate time for the 5200 to cure. I would still suggest you provide some teeth on the plastic (sand it) for a better grip.

As example if its power, during an America's Cup (sail boat race) we changed a keel to further experiment with the design. One of the yard guys used 5200 instead of a more suitable material. When we went to take the keel off (with all bolt nuts off), the keel would not more a bit!! That was about a 18 ton keel.

It should work for you. Just curious, why UHMW instead of a harder material like G -10?

Cheers,

Kent

[Walt Nagel]

Thanks everyone for the advice. I will say though that it must be bonded to the hull. You do not want to use mechanical fasteners because the will eventually loosen as the UMHW expands and contracts. You will get leaks and rot as a result, as well as a lot of other problems. This not a fishing dory (though it could be used for that) but a whitewater boat like this:
http://wileywales.com/dory.htm The UHMW with the fiberglass embedded into it is what I need to make it stick. Does anyone know the exact name of this material or where I can find it? And Kent, I'm not sure what G-10 even is, but UHHW can not crack and is slippery, so it will slide over rocks and won't get hung up on gravel bars easily.

[Steve knight]

There are bonding agents for UHMW. I have a sample out i my shop that has fiberglass embedded in it, so epoxy would work. Check out his link. Garland Mfg These folks know UHMW. I also have some UHMW tape that has sticky adhesive back. I've had pieces in place for years and the adhesive is still working. When you peel of the4 uhmw the adhesive stays with the UHMW not on the substrate.

no regular epoxy would work I use the stuff as a glue board and epoxy just pops off along with gorilla glue and everything else.

[Greg Hines, MD]

According to the "This to That" website, they recommend:

http://www.amazinggoop.com/amazinggoop/index.html

That is one handy website.

Doc