: Because of committments, I will not be starting this until the
: middle of June. In the meantime, being the engineer I am, I
: enjoy the armchair analysis. Believe me, my projects do not stay
: in Dilbert's cube. I have a roaring production area in my
: basement, but I like to know what I am doing once I start.

: I also need to choose the kayak and have a fellow in my whitewater
: kayak club with a Night Heron that I want to try. We have not
: been able to get together yet. I would also like to try a
: Petrel. I know many have just jumped in, but I have a problem
: doing that without having some feeling for the characteristics
: of the kayak I will end up with. After all, 300 hours of work
: should result in a satisfactory result! I tried a strip built
: kayak the other day that was about 19 inches wide and after
: about 1/2 hour, my core was sore from trying to maintain
: stability.

: By the way... The Kayak Craft book by Ted Moores talks about
: keeping strongback discrepencies within 1/16 inch (see pg 5-15).
: I know that Nick talked about a 2 X 4, but even a 2 X 4 made
: with good quality plywood that is TRUELY 2 X 4 inches would have
: some flexibility over 16 or 17 ft. If a 4 inch schedule 40 PVC
: pipe is marginal after 14 ft, how can a 2 X 4 be considered
: better?? I have had no experience with anyone using an internal
: strongback. A friend of mine is using an external strongback for
: a canoe he is building that has the structure and stability of a
: good workbench. Someone help me understand what appears to be
: some conflicts about internal strongbacks here.

First basic thought about an internal strongback should be: "How the heck do I get this out of the completed boat" In many cases the plan calls for cutting it to pieces, which can be pulled out of the cockpit. Cutting a 2x4 aluminum extrusion will try your patience, and cost a lot. You make the strong back stiffer by putting more supports under it. Wallsof a house are supported by 2x4s spaced 16 inches apart.
You don't need such support for a 40 pound boat. Build legs under the strongback, or rest it on sawhorses. Put one support a foot or two in from each end. Another one goes in the middle. If you detect any sagging, add intermediate legs.
Aboriginal canoes and kayaks didn't use strongbacks. Instead, the gunwales were constructed first. These provided support and a base reference for the rest of the boat's parts.

300 hours is average for a first strip-built boat. That includes the hours spent cutting the forms and setting them up on a table, or a strongback. If you go with a plain board for the strongback youcan devote more of you time to getting the strips on neatly.

Right now you should be finding a design which fits your physique and your paddling abilities. Once you get the plans, go with the strongback the designer recommends.

PGJ