: In order for everything to work out fair the forms need to be pretty close. I
: would say a tolerance of about 1/8 inch and no more.

What???? When I've set up the forms for a large sailboat, I tried for 1/16", and it does make a difference. For a kayak, it's not only more important, but easier. Well, easier if you don't follow what most recent books tell you about setting up your molds. For my kayak, I used a box beam, 3" square, with 1/2" thick walls. This is light, has transverse stability, can be rotated so you can do the sides with your work on top by using a cantilever on the top of your supports. The beauty of this setup is that you start by planing the top of the box absolutely flat and level, run a straight line down the center, and align the molds to the line, making sure each is level on it's own lines. Once it's screwed down to that box, nothing moves. Instead of cutting a hole out of the center of the molds, they can be built up from scrap lumber, all planed to the same exact thickness. Each mold is made from four pieces, glued together with a construction adhesive. I glued all my molds one evening, and cut them all out the next morning. And I didn't use a single clamp.

Folowing the books, however, I don't know how close you can really can come. I sure wouldn't want to have to do it that way.

Al