thanks so much for the advice! This is really helping me wrap my head around what has to be done and hopefully I can plan it out ahead of time.
Greg, you are correct the luan between the aluminum frame and filon is also damaged. I am going to get out as much as I can then fill in the space between the aluminum and filon with something (not sure what).
Next step will be to rebuild the wall layers. What you see in the picture is the last thin layer of luan that is stuck to the filon. The luan actually delaminated from itself. Rather that scrape it off, I think I may just leave it. It is obviously stuck on there very well since I cant scrape it off. Do you think I need to spray something on that discolored section (mold?) to kill it first?
Once the area between the aluminum and filon is filled in and the mold killed, I plan on rebuilding the wall by using an epoxy from West Marine. after reading a lot, it seems this is the best to use. What I'd like to do is put a layer of epoxy on the inside of the filon (well, actually the thin layer of luan that is left) put new luan, layer of epoxy then the XPS board, another layer of epoxy then the final (inside) layer of luan (actually may use a thin paneling that will look nice).
When the layers are all put together I will clamp the entire section of the wall together. How? well I am thinking about 2 or 3 2x4s on the outside holding a sheet of plywood in place. Then run long ratcheting straps from the top of the 2x4, around the roof and under the cabover to the bottom of the 2x4. On the inside of the RV I will put plywood against the newly rebuilt wall and brace it against the wall opposite it in the cabover. I'll need something adjustable so I can get it nice and tight. Maybe 5 or 6 shower curtain rods? Of course I will put plywood on the opposite wall so the shower curatin rods dont poke a hole in the luan on that side.
I drew a really terrible sketch of how it will look from outside the damaged side (drivers).
This is by far the biggest projuect I've taken on, so I appreciate any advice or critique.
Thanks
John