Lay your forms on a sheet of paper (newspaper works well for the big forms) and use a pencil to trace around the edge of the form. Fold the paper in half and try to align the lines on the paper.

If you get the lines to match, the fold is your true centerline. lay the paper back on your forms and mark that on them for use in aligning the forms later.

If you come close to getting the lines to match, determine your centerline, and then use the paper to see where one side is high, and the other is low.

As mentioned in another post, you can shim in the low areas with tape or use glue, screws, staples or nails to hold on thin scraps of wood -- even toothpicks. High spots, of course, can be removed by sanding.

Compare the tracings you've made, with the forms that are in front, or behind. This will help you see where the changes are taking place. Just stack them up. From one form to the next the change in size should be pretty even. That is, iif form #2 is an inch smaller on the left side than Form #3 is, then it should also be an inch smaller on the right side. If not, then one of the forms has been miscut and need to be shimmed or trimmed.

Sometimes the forms are perfect in shape, but mounted at a slight angle on the strongback.

: The sander was borrowed, I hate to ask to use it again, and I really don't
: want to go out and buy one.

: Please tell me what to do!

Shaping the strips of the hull and deck, finishing the fiberglassing, and varnishing all call for extensive sanding. Buy a sander. You'll need it. Trust me on this. And get a respirator so you don't breathe all the dust you'll make with your sanding.

PGJ