Thanks everyone. That's the info I needed. I'll try some of the slow cure 5200 to seal them in place. I don't have a form from a place in the boat that would make a suitable bulkhead template (the nearest form that wouldn't shrink the cockpit too much was directly underneath the lip of the hatch, and that's overly far foward for the person who is going to be using this boat). I'll either be trying to hunt down some of that kneadable putty that hardens when it cures (I think it's called engineer's spline), and making an outline around the inside of the boat with that, or maybe using an adjustable angle finder and ruler to take measurements of the outside, and then just make a template out of those measurements and cut a cardboard version out. I could shave that down until it fit, I guess.

If anyone has any better suggestions, I'm all eyes.

-David