Yes, Paul and the rest of you have been very bad influences!

Now to the update:

I'm copying the 17' kayak described in Putz' book, but am using the 1/2" grey electrical conduit PVC instead of wood. I used the dimensions of the forms in Putz to make PVC ribs - these are angular rather than rounded, so I easily drew the form outline on plywood and then put decking screws in the corners. I filled the PVC pipe with tightly packed sand and capped it on both ends with duct tape. Then I used a heat gun to soften the pipe and bend it around the screws to form ribs. After the first couple of ribs with heated sand, I abandoned that part of the process. Since the joints still required heating from the heat gun, there was no positive benefit I could tell from heating the sand as well. The ends met at the top of the deck at a 45 degree angle and are fastened with a PVC joint at 45 degrees. These ribs appear remarkably strong, and took about 2 hours start to finish for this plodding novice to make.

I have built a "strongback" (I'm still learning all these terms, so please be patient if I get it wrong) from some 2"x4"s and sawhorse legs. I've fastened the keel (1/2" PVC, of course) to it, and today need to mount vertical supports to which I'll attach the ribs I've made so I can start adding the stringers. The next step will be to make a C-beam with 1/4" plywood joining 2 PVC stringers. This will be in place of Putz' truss on the gunwales. Also, instead of building the boat upside down as per Putz, I'm building it right side up. Just seems to make more sense that way.

My current plan is to join the stringers and the gunwale truss to the ribs with cable ties - they're cheap and easy to do. When I want to dismantle it, there's just some snipping to do, and when I want to put it together, it means a dollar's worth of cable ties. After that, I'll need to attend to the floor of the cockpit.

I've got the PVC tarp from a billboard that I'm planning to use as a skin. I've discovered that I can heat weld it very effectively with a clothes iron. The current plan is to use a folding seal (like a dry bag) on the deck and then lace up the deck like a shoe to hold the fold in place. This would allow me to fully assemble the boat and then lace up the skin. BTW, the PVC fabric was mine for the asking from a local sign company. It appears highly durable. I'm really hoping it will take a paint(!!!!!)!

The unanswered question is - will it be a success? Seems there's only one way to answer that.

Unsolved problems include:

1. Would there be a better/easier way to secure the ribs to the stringers?

2. How about the coaming (bent PVC pipe, of course!)? I'm thinking about mating it permanently to the skin and then securing it to ribs fore and aft when I assemble the boat.

3. Will I need sponsons? If so, how have these been home made?

4. I'll need to have pegs or a smaller diameter pipe inserted inside my 1/2" PVC stringers to stabilize the joints between stringer pieces (like a shock-corded tent pole). Any ideas? 1/2" PVC pipe actually has an internal diameter of about 5/8". Is there a PVC pipe of this diameter I might find somewhere?

5. What am I missing (other than the obvious critical absence of grey matter between my ears)?

Many thanks,
Wayne