Many good ideas, thanks. The trailer is a 25' 1973 Coachmen side bath that sleeps 6 comfortably, no kidding. The kind you have probably seen over and over, which is white metal with a gold metal stripe around the center. It has a metal roof with seems, which has been the problem over the years. We are in the North and when snow sits on the roof, those seams tend to open and there's a mess on the ceiling and walls come spring.
I used self leveling caulk a few years back that worked well, but this past spring there were several leaks and there most probably is mold behind the wood side panels and above the fiberboard roof panels. I've thought of Eternabond tape, Dicor, etc.
To be honest, this unit is used by other family members and they don't take any responsibility for maintenance. Guess I'm just interested in spending my energy elsewhere.
We have redone all the cushions and they are still in great shape. The trailer probably has another ten years in it for a bunkhouse only, no water pump, but I'm not interested in spending the money or the time to tear it apart and go after the mold. Sheesh, I'm already maintaining two other trailers. My DW says I should be selling these things part-time. In fact, I just sold my Airstream 34' last spring. Now I only have three, whoopee.
Thanks again for the info, if anybody else has a fresh idea, I'm listening.
