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DivineBob · 11-28-2015, 09:22 PM

Ok, my 1960 18 Footer has the belly pan edges wrapped over the top of the interior wall floor channel, which means that the replacement aluminum must be pliable enough to wrap 180 degrees against itself without failure. What alloy should I use? What thickness?

Thanks in advance.

Robert

Aerowood · 11-29-2015, 09:09 AM

Wrapping the belly pan over the channel was a manufacturing process that was abandoned in later years. It was to keep the belly pan attached to the channel while the shell was lowered on. On later models the pan was just tack riveted to the channel. I wouldn't bother with it if I were doing it. If you insist on wrapping then you can use .020 or .025 2024-t3 as it was originally, but expect some cracking when hemmed tightly over the channel, or change the alloy to 5052 or 3003

HiHoAgRV · 11-29-2015, 11:06 AM

I've used .025 and .032 3003 successfully. The .025 was the original on my '63 and wraps nicer but dents pretty easy. .032 was on a '55 I've done and that is what I went back with.

Use lots of clamps and strips of wood to hold the pan to the C channel and get it lined up before starting the fold.

DivineBob · 11-29-2015, 02:06 PM

Thank you for the info about those wraps not being an integral component of the structural integrity of the trailer. Aero, I appreciate your attention to detail on your projects which was evident in all the posts and pictures of yours I've already seen on other threads.

Another little component I forgot to describe in my original post is that the frame ribs across the front of the trailer, which I mentioned are just regular thin walled c channel material, are also not extended all the way down to the floor c channel.

????

They are about one inch short of reaching the channel so the craftsmen (cough, cough) from the Airstream assembly line decided to sister in 18" sections of c channel, placed back to back with the existing short ribs (mmmmmm short ribs...) and pop riveted them together with...

Wait for it...

One rivet!

This California trailer was never meant to be in a tornado I guess, or mildly aggressive wind storm for that matter. Geez!

So now I got a new problem, making the proper length replacement frame ribs. I'm sensing a visit to harbor freight for a 30" brake. So what alloy is best used for these new replacement ribs that must have two bends at a 90 degree angle?

Thanks in advance.

Robert

Aerowood · 11-29-2015, 04:06 PM

Just use one of the following 6061, 5052, or 3002 in that order with the same thickness or one gauge heavier then the original.

MarkR · 11-29-2015, 04:06 PM

fwiw, my front "outrigger" frame ribs (which I'm thinking, are what you're talking about) don't go out to the C-Channel. They stop short, and DIDN'T have anything "scabbed" on to reach out to the C-Channel. Maybe the person building yours actually went "above and beyond" . . . I re-built mine the way they originally built it - so no connection out there at the corners - just the plywood/channel/skin connection - which I'm thinking is sufficient.

And also, fwiw, I used 3003 for my belly (I think that's what it was originally). Make sure (just my opinion) that you don't get a tempered alloy, as the 4 corners are pretty (as in "very") difficult to "configure".

Love to see some photos . . . 1960 was the best year (wink wink).

Oh, and in case you haven't read elsewhere in the forums, the original axle spindles on Caravels have some failure history you might want to "read up" on (and maybe the "vintage" of that axle issue is different than yours(?)).

DivineBob · 11-29-2015, 05:47 PM

http://theadventuresofflyingtoaster.wordpress.com

Can't attach any pictures to this forum off my ipad so the above link is to my blog with progress so far including pix.

Thanks Aero for your reply. I think I will go with a more malleable aluminum for the detailed tucking needed around the edges. There's a lot of transition cuts I need to trace off the original pan I'll use as a template. Loved your posts about nut plates instead of rivets for belly pans. I don't anticipate the need to have access to the underside frame that often. I will POR-15 everything during my shell on plywood repalcement, put a layer of Reflectix on and be done with it.

Thanks for the heads up Mark. I took the axle off so I could Egyptian roll the originally 8'4" tall beast under my 7'10" garage door on its frame, so now would be the time to get the axle checked out by a professional. Not very savy with the workings of that piece of the trailer, but since it is a leaf spring only set up, I've been told that it is likely the most reliable axle around.

Thanks again,

Robert