: . . . p.s. when you run out of canvas what will be your first choice for skin
: boats?

Not only would skinning a kayak with whale skin be authentic, but I'd never need to hunt for a paddling companion, nor could I ever get lost. I'd be constantly surrounded by many activists from Greenpeace and I am sure they would certainly tell me where to go.

Seriously, though. I think I'll let the whales alone and use a polyester fabric with hypalon, PVC vinyl or urethane.

That is assuming I don't cover the things with 1/8th inch plywood, glass cloth and epoxy resin.

1) I'm impressed with the service life of Klepper hulls (estimated at 25 to 35 years, and I've personally seen one that was two generations old) and they are made of polyester and hypalon. Polyester in a 13 ounce weight or a bit heavier sounds awfully tough. I'd get it from George Dyson. The hypalon comes in colors so I don't have to paint it. The hypalon coating is also able to be solvent sealed, so the overlaps at bow and stern can be made watertight and reinforced easily for strength. If Dyson had the colors I wanted I'd get it from him. Otherwise, I'd probably get it from Gaco. Their midwest distributor is in a Milwaukee suburb, about a 2 hour drive from Chicago, and Milwaukee is a great place for a day trip with my girlfriend.

2) McMaster-Carr has 2 polyester-reinforced fabrics which are PVC coated. Their price is reasonable, the material is already coated, so I would not need to do any painting or coating at all -- so no added costs or time. I've seen similar heavyweight fabrics used on inflatable boats with long service lives. You can solvent bond, or heat weld the seams. Even major rips and tears can be fixed in the field with a roll of vinyl tape. (or duct tape). Since I would not need to apply a coating or wait for one to dry or cure, this would be the fastest and cheapest route to get a boat in the water.

3) I'm intrigued by the information I saw on the Gaco site about the boats built by Bill Low of Willow Kayaks. According to the site, he uses two coats of exterior polyurethane and covers that with a coat of Gaco's urethane. I've been impressed by the water resistant ability of very thin (1 -3 ounce?) nylon that was urethane coated. It made for a nice rainsuit, and nice tent floors, so I'm thinking that thicker fabric with thicker coatings would be fantastic. I'd have to sew seams, or be very careful with staples or tacks on the bow and stern, and probably overlap them with reinforcing fabric, so construction would be a bit more involved than with the first two methods, and maybe an hour or two more for the sewing. But, the coatings would go on as fast as the hypalon, and the material would not take as long to cure before use. so, the cost and time involved would place this between the fabric from McMaster-Carr and the hypalon.

I'm not sure about how well the urethane would roll and fold. On tents it was great. But, for a collapsible, take-apart or folding boat I'd probably use one of the first two methods.

PGJ

Here is a Klepper Aerius: