Keeping water out.

[GeocamperAS]

What to seal the rivets and seams with. I just finished removing old plywood. I found the insulation wet. I fixed all belly pan rivets. I am afraid water from road spray could still get in.

[Lotus72]

Did you ever get a reply on this? We have the same issue on our AS

[boatdoc]

Originally Posted by tiger

What to seal the rivets and seams with. I just finished removing old plywood. I found the insulation wet. I fixed all belly pan rivets. I am afraid water from road spray could still get in.

Hi Tiger;
There are many shools of thought on this issues and everyone will have different opinion. It is not my intention to disagree with anyones idea, but I will present you with mine. First, there almost no way to seal your belly pan space effectively. Passing tractor trailers create so much over pressure that water travels straight up via tiny crevices everywhere.
I have observed it via remote camera installed with a light source in the belly pan of my Argosy. With my new SS frame, the belly pan section are one piece 100" long and are oriented side to side from one lower trim molding to the other. Each section, front to back is joined via connecting H trim laying flat with 1/16" pockets on each side into which belly pan sections are slipped into. At first I was tempted to use MMM 5200 to seal the joints. Something told me to investigate first what happens in the belly pan while traveling on the turnpike in the rain. This is where the idea of a camera in the belly pan was born. As I was passing tractor trailers I have observed a periods of vacuum in my belly pan as well as high over pressure within seconds apart. This is when I decided to incorporate small SS screen vents at the back end of each 4' panel to drain the water. I was going to install the same in the outrigger section but there was sufficient space between frame and the belly pan sheeting to drain into center cavity. This is where bubble foil insulation has advantage over fiberglass which retains water. I even have a roller type cage fan which draws 0.2 amp which I turn on after the trip to speed up drying process.
If you find a way to seal your belly pan 100% you will be combating the condensation anyway. IMHO the best way to prevent it, is to vent it. Thanks, "Boatdoc"

[TG Twinkie]

Venting and draining the belly pan, what a novel thought. I have asked several times about why AS doesn't vent the belly of the beast. It makes perfect sense to me. It is the same reason we vent the attics and crawl spaces in homes. To prevent condensation build up.
It should be evident that this moisture will cause damage. I've read in several threads here that members have significant problems with moisture in the living space of their trailers. The solution that most come up with is to open the vents and remove the moisture. It only makes sense to do the same thing in the frame space above the belly pan.