> Can polypropylene be used as skin on a kayak? I have access to some heavy
> gauge (I don't know the actual weight) poly mesh. The price is
> right--$.90/running foot, 102" wide. It's really tough stuff, no give
> or stretch at all. Does skin material have to have some play? I'm going to
> make some small panels with some scrap I brought home and coat with epoxy,
> paint etc. Any info or opinions will be welcome. Thanks, Tom

Polypropylene has kind of a waxy feel to it, and it tends to resist glues, paints, stains, etc. They bead up on the surface.

If you can find anything that will stick to it and make it waterproof then go for it.

Experience with epoxy ( and polyester resin, too) mixed in polypropylene mixing cups is that slight flexing of the cup is sufficient to completely dislodge any cured resins. Even if you were able to apply a coat of epeoxy resin that completely covered the mesh, surrounding it on all sides to make a continuous, flexible, waterproof covering that completely encapsulated the fabric -- I think it would still fail in a very short time. The normal flexing of the fabric would cause delamination over large areas of the skin on probably the first mile.

A rubber based coating might work if you put it on thick enough. It wont adhere to the fabric very well, but if enough gets trapped in the fibers it should be pretty durable. You can try an elastomeric roof coating. Do both sides of the fabric, and hope the stuff soaks in far enough to get a good grip on the weave of the fabric. It might be hard to get regular latex or oil based paints to build up a thick enough coating to be durable. You may want to greatly dilute the first coat of anything you try jsut so it will soak into the weave, and hopefully get something trapped in there that later coats can bond to.

Tar might work. Messy stuff, though.

Solid Polypropylene is used in making rotomolded kayaks, and some canoes. If you get it thick enough it can be pretty strong.

I dont know of any solvents for it. Ususally, if you want it in a liquid form you heat it up.

It would be interesting ( to a pyromaniac) to try to coat a polypropylene fabric with melted polypropylene. If the fabric was thick enough (unlikely) and the molten plastic at exactly the right temperature (also unlikely) someone could try to apply the molten plastic to the fabric and hope that the fabric did not melt through before the liquid plastic solidified. The fabric should melt just enough to weld the fibers to the coating, though. (extremely unlikely) Seriously, though. Don't try this at home. My experiences with molten polypropylene have been extremely painful.

If the fabric is woven tightly enough to have some water repellency, you might consider using it for a deck fabric. With a reasonably high peak on the deck, splashed on water might just roll off rather than soak through.

If the fabric is reasonably opaque you might use this as a sunscreen and store your boats under it, instead of using a tarp.

Just a few ideas.

Paul G. Jacobson