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Alumi-Naught · 06-12-2005, 10:56 AM

After finding water dripping from thr belly pan behind the wheels where the belly pan and the banana wrap meet, I dropped the pan to try to locate the source. I think I have sealed the leak, however the belly pan is corroded where it meets the rear portion of the frame. Can I cut the corroded section (about 2-3 inches) off and rivit or weld a new swction on? Or should I replace the whole pan.

CanoeStream · 06-12-2005, 11:10 AM

The bimetallic reaction (steel frame & aluminum) causes this to happen eventually. The belly pan joints should breathe and are not intended to be watertight. Would it strengthen it enough to just take out a few rivets, fit a strip of aluminum to serve as a backing plate, and rivet that in place along that rivet line?

Now if you want to see really corroded belly pan...

rluhr · 06-12-2005, 11:46 AM

A patch is fine. Make it a few inches bigger than the piece you cut out, and rivet it to the existing aluminum pan (and steel frame) with 3/16" pop rivets. No need to replace the entire pan unless it is like swiss cheese or corroded extensively.

But where is that water coming from?

Alumi-Naught · 06-12-2005, 06:58 PM

Thanks for the reply, That is what I thought I would do. The water was comming in just below the rear storage compartment where the rear bumper cable/hose storage compartment meet the rub rail. Thanks again

bredlo · 06-12-2005, 08:36 PM

Canoestream, this is something I never fully understood. In my understanding, the original fiberglass batting insulation sits in that area, under the floor and above the belly pan, kind of surrounding the frame, right? If the belly pan isn't watertight, doesn't that compromise the fiberglass almost immediately?? If that's the case, I'd rather go without insulation under the floor at all (which I realize many people do during renovations.)

**jcanavera** · 06-12-2005, 09:46 PM

Airstream quotes that they don't want the belly pan to be water tight in order to shed moisture that potentially gets in there. I know my Safari would shead water that somehow got into the belly area when I washed the trailer. Rainstorms didn't seem to get in there, only washing the trailer. I took the trailer back to the dealer all concerned and was told that its not an abnormal event.

Jack

rluhr · 06-13-2005, 06:20 AM

Brad, Jack is right. It's also a misconception that water immediately compromises fiberglass insulation. Fiberglass insulation does not absorb water and will dry out. It should not damp down or lose significant insulative quality.

In a house you'd replace wet insulation because it is typically mounted next to wood studs and drywall. That's a formula for mold. But fiberglass also cannot support mold growth by itself (there must be some organic material for the mold to eat, i.e., wood, paper). So a little water in the belly pan doesn't cause a mold problem in the Airstream, as long as it can dry out fairly quickly.

However, sealing up the belly pan will cause problems since it locks in moisture and gives rot a chance to get started on the wood subfloor. The belly pan is designed to be self-ventilating, as Canoestream pointed out.

enduroryda · 04-11-2006, 12:41 PM

Quote:

Originally Posted by Canoe stream

The bimetallic reaction (steel frame & aluminum) causes this to happen eventually. The belly pan joints should breathe and are not intended to be watertight. Would it strengthen it enough to just take out a few rivets, fit a strip of aluminum to serve as a backing plate, and rivet that in place along that rivet line?

Can I just drill out the old rivets and use aluminum flashing cut into strips or do I have to buy a special aluminum?

I have several areas were the rivets are corroded...also a nice rot spot next to my streetside leveling jack...any ideas?? Thanks Ann

Zeppelinium · 04-11-2006, 04:01 PM

I just finished POR-15'ing my frame in the belly pan area (the cross frame members were slightly corroded in the front and progressively worse toward the rear). When I opened it, only a small section of the fiberglass had fallen down from the floor above, but it was wet and had to have been wet for weeks. On the other hand, it's a 1971 Caravel and I was surprised that 80% of the fiberglass looked fine, just dusty-dirty. I'm replacing it all with foam, see thread "new axis axle". Probably have photos up tomorrow night.