Hi Brian, On my first boat (the problem child) I resorted to using some scrap pieces cut to the same width as the forms, I put them in as needed through the cockpit and hatches while I was taping the deck and hull together. I found that by using a hole bunch of tape, that the friction between the deck and hull taped tightly together was enough to hold it in place once the scrap was removed. The straps will help move the pieces around from the outside as well. try using the little pieces I showed in my last posting they really work! I must warn you that once you move the deck and hull around to match the shear seam up, you may find that if you are using flush mount hatches they will no longer be flush as a result of the deck changing shape. It happened to me. If I had it to do over I would have recessed the hatches more and compensated for the change with the hatch gasket. Hope this helps! Don't worry all will work out!