03-30-2014, 06:54 PM
Jimmy: just for clarification. I started throwing wrenches at airplanes in 1970, I'm too old to figure out how long ago that was. It was long enough ago that I flew in the exact DC-3 that's hanging from the ceiling of the Henry Ford Museum in Dearborn, Michigan.
Anyway, the major source of aluminum corrosion on the early vintage Newells (my 77 coach for example) was that from the floor on down the aluminum skin was laid over over a steel structure. Around the wheel wells it was laid over the steel sheet making up the wheel well. Originally there was a polyethylene sheet separating the steel and aluminum, but over the years the sheet deteriorated and it was possible for moisture and road salt to wick into the gap between the two and pinholes and other problems result. The skin is easy to replace because it is held in place by screws only along the length of the top and bottom behind trim strips. There are no other fasteners. In later years, or when doing a rehab, Newell went with the double sided sticky foam tape to hold the lower skin in place. That is probably a more secure and durable approach.
From the floor up over the top is an aluminum structure and aluminum skin with foam insulation behind the skin. If a leak occurs and the foam holds water that would not be good as you say. The lower skins are an entirely different situation.
Anyway, the major source of aluminum corrosion on the early vintage Newells (my 77 coach for example) was that from the floor on down the aluminum skin was laid over over a steel structure. Around the wheel wells it was laid over the steel sheet making up the wheel well. Originally there was a polyethylene sheet separating the steel and aluminum, but over the years the sheet deteriorated and it was possible for moisture and road salt to wick into the gap between the two and pinholes and other problems result. The skin is easy to replace because it is held in place by screws only along the length of the top and bottom behind trim strips. There are no other fasteners. In later years, or when doing a rehab, Newell went with the double sided sticky foam tape to hold the lower skin in place. That is probably a more secure and durable approach.
From the floor up over the top is an aluminum structure and aluminum skin with foam insulation behind the skin. If a leak occurs and the foam holds water that would not be good as you say. The lower skins are an entirely different situation.
Jon Kabbe
1993 coach 337 with Civic towed