The outer skins on my truck are .050 alum & originally installed with 3M VHB bonding tape with no screws or rivits.. Before I started on the interior, I had a couple seams come loose. I bought a pneumatic calk gun & 18 tubes of sikaflex 262 and forced it betweeen the sides of the (structure) square tubing & the aluminum skins, then used my finger to further force it into space (btwn the sq tubing & skin)
I've not had any further problems.
Prior to applying the sikaflex to the structure of the truck, I took a piece of scrap tubing & aluminum skin and laid a 1/2" X .040" ribbon of sikaflex ibetween them. A day later, I couldn't pull the alum skin loose without destroying it. If I were to do another conversion, I would definately use sikaflex. I believe it would hold better than anything else but still allow for expansion & contraction of the outer skins, as it remains somewhat flexable even after it has cured.
I researched the 252 product & found that one of it's uses is in the manufacture of commercial truck bodies.
You will need to clean all surfaces of paint, primer grease, oil, etc, . . . According to most sources I was able to find, it bonds best to clean metal, plastic, or ??
Yes, it's a bit expensive, but you DO NOT want problems after you close up access to the inside of the structure.
