Just a suggestion...most aluminum fabricators sell a rolled adhesive product (4" wide) that is used to seal the seams over insulated aluminum roof panels. Sticky on one side and white vinyl on the other. I've used the wide stuff from H/D and found it was a bit tricky to handle and when it got heated up it gave off a petroleum odor. The 4" stuff is easy to apply inside the doors and other hard to reach places and stays put!! It sells for about $13.00 a roll and I used 3 rolls to do my cab. Hope this helps.
