Too much water in the belly pan

[Bourbonshot]

Working today on our new to us 1975 Sovereign, we were chasing down leaks and found that under the lower side trim line (between 2 & 3 on the attached figure), the curved section of the belly pan (3) was riveted to the OUTSIDE of the side sheet (2). According to the 1975 service manual (p. 37), the side sheet is supposed to be on the outside of the curved section of the belly pan so water falls away from the trailer and not into the belly pan. We now understand why water was dripping out of the belly pan! Both sides of the trailer are the same and appear to be original. Does anyone have an explanation that we do not see?

[rmkrum]

Somebody did it wrong when built or during refurb??

[Bourbonshot]

That’s what we are thinking, but we wondered if we were missing something. Everything looks original on this trailer except the upholstery and radio. Thanks for your response.

[dbj216]

Rainwater in the belly pan is very common with Airstreams I think. Our 86 certainly has it, and my 75 Overlander has it too. I think most of the water enters from the bumper storage area which is generally unsealed. On our 75s, the bumper storage area is the holding tank drain piping unless you have a mid bath, rear bed model (lucky you.)

I have replaced three belly pans and my Overlander is the 4th waiting for the same treatment. I have drilled 1/4" diameter drain holes in the new belly pan so rain water can leak back out again. My 75 Overlander was built with the side wraps riveted outside of the exterior skins. The sealant used in this joint on my trailer was very good indeed. But rain water can get to the belly pan from the rear, and certainly from the infamous rear bumper decorative aluminum piece that fills the gap between the body and the bumper. This is a main cause of rear end subfloor rot and eventual rear end separation and the frame sag. Not good.

My idea is to let out any rainwater that gets in. I also think the drain holes provide a little drying air circulation under there.

David

[TG Twinkie]

Homes are vented in the attic and crawl spaces.
Always wondered why A$ does not vent the belly pan or put drains in the C channel.

[rugjenkins]

My 75 argosy had the belly wrap over the exterior skin too from factory. Not good. I re-worked the belly wrap to go under the exterior skin. There are always improvements that can make these campers better. Not to bad of a fix. Btw the 70's trailers had lots of cost cutting measures by Beatrice foods who purchased the company in the 70s.

[Bourbonshot]

So we are not alone! Thanks for your help, everyone. Good to know some possible remedies.

[dbj216]

I know what you are saying about Beatrice Foods and Airstream. Sometimes a corporate buyout doesn't work out so well. I was apprehensive about buying a 1975 Overlander fearing the "cost cutting" compared to my old 66 Trade Wind. But to my surprise, the 75 isn't too bad at all. It has many construction features I like. But the rear body seal ain't one of them.

Here is a photo of the "high water mark" on my rear cross member showing how much water sat in the belly pan at one time. I drilled holes in the belly pan to let the water drain out.

You might also find a goodly bunch of wet fiberglass insulation under there.

David