Hmmm, that's odd...

I averted a miscalculated disaster yesterday by discovering the maximum beam (width) of the kayak had unknowingly grown from 23 1/2" to 24 1/2", an whole inch of near chaos. It came to my attention as I was attempting to fit the two plywood bulkheads in the fore and aft sections of the boat, there was just too much width room to understand. scratching my head, I whipped out the tape measure and to my surprise the boat's width was an inch too much. 

Let me see if I can explain what happened. The boat plans clearly state the proper beam of 23 1/2" and this is achieved (as instructed) by using a scrap spreader stick, cut to the necessary length. This stick is then wedged between the two side panels (see early blog post with the movie) to hold the side panels apart. I cut the spreader stick to exactly 23 1/8", which is shorter than 23 1/2" as to account for the two 3/16" plywood panels on each side (23.125" + .1875" + .1875" = 23.5"). Perfect. And when I first spread the side panels apart, it was perfect. 

What happened, I've deduced, is that the side panel beam became wider as I stitched the panels together. This occurred because the side panels at the shear clamp started to cantilever out as the lower portion of the panel was drawn in towards the centerline to meet the bottom panel. This movement was enough to add 1/2" width on either side. wow.

So I removed the spreader stick to shorten it to correct for the errors, cut it to size, pushed it back into place... 23 1/2". Now it's perfect!