The panels are about 1” thick, comparable to the thickness of the current 1x1 square tubing-framed doors. The outer skins encase what looks like a resin-soaked version of the inside of a hollow luann door. They will need at least a basic perimeter frame of 1x1 to use the existing hinge and latch setup. I’m wondering if I could rout a channel so that the tubing can get bonded to the inside of the outer skin and sit semi-flush with the inner skin? I’m interested in hearing what others may have used to bond aluminum and fiberglass as well. I can’t really work on this for another stretch, so I’ll take some time to play with ideas and do some research.