Work at it progressively. The first wrap of tape may not be enough to hold everything in place, but as you add more tape it will stay better and better. I've pulled together boats that had a 40mm difference between deck and hull.

I haven't bothered, but some temporary sticks until you get everything secured will help.

> Progress has been good so far but I have hit a problem jointing the hull
> to the deck. The hull has closed in a about 10mm and I am having all sorts
> of trouble getting the tape to hold the hull in place. Could I glue the
> seam or what, this is so frustrating. Phill