To update on my valence project:
I had to leave the project for a week, due to some business, but I am back at it. I found a bulge in the wall below where the valences sit, but decided that, since I was planning to repaint in any event, I could cut into the bulge and determine whether I could flatten it. Well, that didn't go well.
Beaver built these coaches with an aluminum box tubing frame. They infilled between the tubing runs with white styrofoam and covered the whole with 1/8 plywood, inside and outside. Because there were some places they wanted a more secure fastening of the plywood than just to the styrofoam, there are some softwood 2x2s, to which the plywood is stapled. Around the windows there may also be some 1/2 plywood, depending where the nearest aluminum box tube is.
The bulge I opened was caused by water getting into the wood, both the 2x2 and the plywood, and rotting it. The particular location is between the two big windows on the passenger side. I eventually found the source to be the top of the window ahead of the table, under the Girard awning, and the leak actually went upwards through the plywood covering, to the underside of the aluminum, along to between the windows, and down to the floor, filling the space between the vertical aluminum and the white styrofoam, a space of about 4" in which I found a mess of soggy black mush that used to be a 2x2 and a 2x 1/2 plywood. At the bottom, just above the floor, the thin plywood covering the inside of the wall was letting the water out onto the floor at a slower rate than it had been coming in, so the cavity acted like a water glass, the bits of rotting wood I pulled up out of there were actually dripping wet.
There were other places that the wallpaper was lifting, which I now treated as "suspicious", so I attacked them all with a chisel. I found some wetness is a few other spots, but nothing like the first spot.
The reason this problem exists is that in the original build, Beaver used the cheapest grade of 1/8 plywood for the covering of both sides of the walls. The glue isn't water proof, so as soon as it gets damp, the plies separate and the plywood turns into a sponge. To top it off, there is nothing done to make the window openings waterproof. They should have been covered with a layer of epoxy, or even a layer of caulking.
The inside of my coach is starting to look better now, as I have cleaned and dried all the places that I opened up, then I put new 1/8 ply back on where I had taken the bad stuff off, and am in the process of painting and filling. When that repair is done, I can get back to the valences.
I have another valence completed and ready to go in, and all of the rest of the wood ready for assembly, but I have to go back to Vancouver tomorrow for about a week, so won't be finishing this project any time soon.
