Awright, here goes. Conduit PVC for a kayak is without any doubt one of my nuttier ideas. And it might work. I built a Walrus frame out of PVC, then failed at skinning it and sent it on to the happy kayaking grounds in the sky. The good ideas for its construction came mostly from this list (probably 80% Paul Jacobson). The bad ones were uniquely mine.

The good first:

1. Cross sections were made of heat-bent sch. 40 3/4" conduit PVC. I traced the station dimensions on a piece of plywood, anchored nails at each corner, filled the pvc with sand and capped it with duct tape. Then I bent it around the nails using a heat gun and joined them with pvc fitting. And these suckers are REALLY strong.

2. The gunwales were I-beams of PVC stringers from which I cut a 1/4" strip. 1/4" plywood hooked them together, and the whole thing was glued with liquid nails. This part is also REALLY strong.

The bad, inadequate, and ugly (and possible remedies):

1. The stringers were flimsy (other than the I-beam). On the baidarka list there's a guy who cored the pvc with fir (?) dowels he made on a router table. He claims they're mighty strong, and I'm mighty curious. He speaks of the pvc's tendency to collapse when challenged and the fir's tendency to splinter (using vastly more impressive physics-type terms), and how when combined, these two materials make up for each other's weaknesses. I sure want to try it.

2. The gunwale/cross section connection was with hose clamps. You need something much sturdier. I wonder about lashing.

3. I got a little impatient with all my connections, and figured that zip ties would be the appropriate technology to join stringers to the cross sections. Maybe stronger zips or another way would have worked better. Those joints had a lot of flex.

4. The final folly was an attempt to use a retired billboard tarp for the skin. My seaming methods were suspect, and now I keep wondering if Tom Yost's truck tarp methods would work for billboard tarps. If I ever do a pvc frame, I just gotta go with the billboard tarp (my kids will never remember me as dull, huh?), as a stylistic issue if nothing else. Just kicking this idea around had me paying attention to various billboards around town, evaluating them for their possible use and their various color schemes. I seriously contemplated liberating some 6'x20' sections of a Bud Light billboard with a utility knife. Would have made a dandy skin. But I am a pillar of my community :-) and couldn't really come up with anything good enough to tell the judge.

I have to believe that a PVC/Billboard boat could be done for well under $100. Maybe under $50, if your scavenging skills are good.

One final thought. When I tried to destroy the thing to put at the curb, it was surprisingly tough. There was a lot of lateral play that would need to be solved, but otherwise that I-beam and the cross sections were seriously strong. Were I to do the I-beam again, I'd use 1/4" HDPE instead of plywood, and I'd make it a C-beam instead. It was the dickens trying to slide that plywood into the groove for the I-beam.

I hope you do it. I wouldn't at all mind being the second guy (or third) to pull it off. Just stay away from that billboard at the Northeast corner of the intersection between I-35 and Rosedale in Fort Worth. There's a large patch that asks me to liberate it so it can become kayak skin.

Wayne the liberator