My TD is completely covered with 0.040" 'mill finish' aluminum, top, front, hatch, & sides. When I was building in 2006 there was quite a lot of discussion on adhesive vs floating. I kinda used a combination of both. I used enough adhesive (PL600 I think??) in just a few 'beads' for each panel to help hold it in place 'til I added enough trim to secure it more permanently, Pretty sure all the adhesive I used has 'released' its hold. I forgot to put a trim strip at the front side of the doors where the hinge is, & a year later while on a trip to Wyoming I noticed in my truck mirror that the skin at that location was sort of 'billowing' a little. I stopped at the next 'big box' home supply store (think it was Lowes?) & bought a strip of 1/8" X 3/4" aluminum, some stainless screws, & a tube of construction adhesive sealer. When we reached our campsite that day I cut & drilled the aluminum strip, & skin at that location, installed the strip & it's been holding well ever since. I've towed the TD more'n 25K miles from south Texas to Pacific NW, including a trip across the Mojave desert in August. It shows no evidence of skin deformation/distortion or any other problem. Sometimes if the TD is sitting in direct sunlight on a really hot day, I can see what may be small areas of 'oil canning' but it returns to normal as soon as the temperature changes.
My TD is 5' wide & I couldn't find any aluminum that wide so I cut & installed it 'crosswise' on the roof, front, & hatch. I cut it for exact fit with a handheld electric shear. On the sides I cut the profile curves maybe a quarter inch larger & after installation I used a trim router to remove the excess. Didn't do a 'build journal' in those days but you can see pix of my build (& since) in my gallery (click on the small camera icon below my user name). If I were doing another I probably wouldn't change a thing about the method of skin attachment...
This pic was made looking toward the Wind River Range in Wyoming, a few days after I'd added the trim strip at front of doors

I took this pic this morning. 8yrs old & still no sign of skin problems (other than needs a wash

)It does show a few dings/dents along the top edge but that's been there since new & is probably a result of staples used as temporary hold during the build...
