It sounds to me, from all the responses, that one needs to worry about the hull shrinking and being too small than the deck "stretching" and getting too big. Is this correct? What does all this preloading do to the structural integrity of the hull as a whole when you're forcing the halves together?

I suppose I could make two sets of forms, like Nick... :-) Nah, too much like work!

I like Ross' idea for prevention with the sticks - I'll be sure to remember that when I start my glassing. Seattle has some pretty drastic variations in humidity/temp from day to day, so I'd best be careful.

Scott.