Wes,
Your thoughtful questions and advices are the ones that really peak my interest. Just a few years ago, I was sitting in my office contemplating what to do with my life while knowing that my company would be massively downsizing the work force of the program I was working on, I had the idea building my own RV just like you. Back then I've never seen a welding machine before but that did not deter me. I Google'd the nearest community college with a good welding program and took courses. So, don't underestimate your ability to learn at any age.
On the subject RV wall. I am not an expert in this area. I've spent quite a bit of time researching fiber glass RV wall and I've take a class on fiber glass making but I've chosen a different approach to build my RV wall. What I do is completely ignoring the delamination issue because I would build the Alum. frame then attached the Alum. skin onto the frame using 3M's VHB tape. The tapes are extremely expensive but they are as tough as rivet. Then, I lined the interior of the Alum with wooden edges. Next, I glued the foam cores. These foam cores came with a thin plastic vapor sheeting already glued on both side. After the foam cores are cured, then I glued on the wood sheeting and stapled the edges with finishing nails. I don't worry about delamination because the VHB tapes hold the Alum. skin to the frame just like riveting except it looks a lot nicer. Basically the foam core can detach or expected to detach (due to heat/cold expansion) from the Alum. skin but they won't go anywhere.
Here's a picture of the wall in the middle of the process described above:
As far as moisture goes. I believe moisture can and will absorb into the wall as you have described but it will not adversely impact the Alum skin integrity. I plan to paint the interior to minimize moisture absorption but I believe a humidifier is the only right solution since water has to go somewhere.
Keep the exchange going. I've love to hear questions and suggestions from everybody. For me, failures are opportunities to improve.
Bucky,
Re: "heels banger"
The platform is set back a few inches from the front edge of toilet seat so you won't hit it.
