Rear belly pan replacement

[Adam.Pyburn]

Hey everyone,
I'm starting to get working in earnest again on my '68 Sovereign now that the worst of the summer heat is over (not to mention I finally made some money!). I've been needing to replace a section of the belly pan under the old black water tank that's basically corroded at the seams. I'm doing a full gut, seal, and restore so no need to remind me to fix the source of the problem before fixing the symptom
Just wondering what type of aluminum to get and a good source. I've previously been led to Airparts inc, which seems like the place to purchase from, so I'm mostly curious what the best grade of aluminum is for the belly pan. Thoughts or links to a previous post I overlooked are greatly appreciated.
I apologize that I can't put up a picture at the moment, but forgive me, I'm on dial up out here on the farm.

Thanks in advance, I know this crowd is good for it!
AP

[Splitrock]

It's a good question. Here we've got some sophisticated truck box/trailer repair companies with shears and breaks who work with mostly big aluminum sheets. I'd thought I'd just order the panel I need from one of them. I might even hire them to put it on for me after I remove the old panel and clean out the pink sludge.

Gary

[Aerowood]

No need to spend the big bucks for 2024-T3 for the belly pan. Use something cheaper with better corrosion resistance like 3003 or 5052 in the .025 to .040 thickness. Let your wallet be your guide here, use whatever you can get the best price on, without paying for shipping.

[till]

Does the black tank really need a belly pan over it. I thought that the galvanized box and aluminum eat each other? I have seen the under side of some of the newer Airstream's and they seem to lack aluminum on the tanks.....

[Adam.Pyburn]

Thanks for the responses everyone, and for the specifics Aerowood. I think I'll probably go with 5052 H32. They say it holds up good in marine environments and is used for fuel tanks.
Oh, and I do need a belly pan there because I'm removing the tank altogether for conventional plumbing and putting insulation between the belly and the subfloor. I know to you traveling types it might seem like sacrilege, but for now I'm just planning on having a nice trailer to live in. I don't have money for axle work or a tow vehicle. Just looking for a cozy space to rest my feet out here on the farm for now. One day though...

[till]

No problem. Just an observation. Best of luck with you new refuge.

[lawyerfloyd]

Belly Pan. I am new to the Airstream site so bare with me. I find some of the terms unusual. Anyway, I am also replacing the underside aluminum sheet that runs the full length of my 1971 Sovereign Land Yaght (27 feet). I am trying not to replace the entire sheet (I presume you call it a "belly pan"?) I have cut off about 8 feet of the rear part and believe that is all I need to replace. Does anyone have experience in just replacing a portion of the undercarriage aluminum. Am I off base in believing i can replace just a portion?

[Adam.Pyburn]

lawyer,
i am planning on only replacing a portion. mine is something like 5 X 3 just at the rear. i'll probably vulkem (standard airstream exterior polyurethane sealant) and rivet the aluminum overlaps and possibly tap a few screws into the steel frame crossmembers for added peace of mind.
ap

[Minno]

The center underside piece of aluminum is the belly pan. The pieces that run along each side and wrap up the outside a bit I’ve seen called side wraps and also called part of the belly pan. Older AS’s do not have separate center and side pieces on the belly as I understand it, hence some of the confusion on names. The four corner pieces are called the banana wraps because of their shape.

You can replace just part of the belly pan. Overlap the seam a couple of inches, and if you can have the seam line up with a frame member, that’s best. Overlap so the piece going to the front is below the piece going to the rear. That way road spray won’t work into the seam as easily.

Do not vulkum the seams in the belly! You want the belly pan to be able to drain any water that might get in there. Also, there are large head rivets you can use that will support the belly pan better than the regular sized rivets. Pop rivets are fine – no need for Olympic rivets on the belly pan. Here’s 2 links to large headed rivets you can use. I believe Inland RV also sell them.

http://www.vintagetrailersupply.com/Large_Flange_Rivets_p/vts-283.htm

http://odmrv.com/catalog/index.php?main_page=product_info&cPath=79&products _id=1055

Chris