Need advise on seams that failed

[Big Rich]

I am a new guy here, first post. I have been looking around this website for some info to help me understand why this problem happened and how to fix it. I recently bought a 1968 24'T Airstream. The seams on both sides of the top roof skin have failed. The rivets have mostly failed (broken, missing, separated seams)and the sealant to mate the seams has turned to a whitish powder when scraped off. The unit sat on the cliff above the Pacific Ocean for at least 14 years per P.O. Most of the other seams still are tight and have some sort of sealant between the skins. There is definitely some corrosion in a few areas, but most of the unit is in tack. My first priority is to make it weatherproof, fixing the two seams roughly 14' each with Olympic rivets and vulkem. I read on this website that every seam on an AS is structural. I am a union Carpenter and understand shear values. I am wondering if these rivets are sufficient. I really do not want to strip the interior skins off to do buck rivets.The interior is mostly original and want to keep it that way. I am also wondering why the sealant failed (salt, heat, sun). Any help or suggestion will be kindly appreciated. Also, I would like to hear an opinon from a profesional trailer restorer or VTS. Thank you, Big Rich

[rugjenkins]

I don't believe the factory used sealant between the seams. That being said sealant does not last permanently, uv rays break them down. I always prefer buck rivets but even the factory will repair panels with Olympic rivets so you should be fine. Sealing the seams is a good practice. Use sikaflex 221, trempro, gutterseal or parabond.

[Dremel]

Don't forget to figure out why it failed.
Rotten floor causing separation movement?
axles?
or maybe someone just walking on the roof in a bad way

[putback]

I can pass along some things I've seen/learned down through the years rebuilding pre 1966's. Exterior skin seams that old often show bad sealent but are ok when you get a few 1000ths back under the overlap. A few loose / missing rivets is normal. However in your case that many sheered rivets in that area suggest a serious problem. The upper hull/body supplies a significant precentage of structural strength. Flexable frame, think unibody. If the axles are "set" there is no cussion, every bump drives the center of the rig up, a millisecond later the ends catch up. Trailer bends like a bow and shears rivets little by little. Worst case scenerio. Frame rails cracked / broken behind the axle mounting plate. Usually caused by set axles. I'm just finishing a new fame on a '63 ambassador for just that reason. And yep bad rivets where yours are. The olympic rivets at that seam would prob be ok if it sits but unlikely up to the task for travel. Solid buck rivets would'nt hold, olympics have far less shear strenght. No experiance with a sea salt environment but in northern new england with winter road salt old Astream frames can melt away like a Hershey bar on your defroster!

[Aerowood]

Post a picture, but what my take is, is that you have severe corrosion in between the seams (this would be the white powder you are seeing). Airstream never has and still doesn't seal between the seams. The corrosion buildup is enough to cause the rivets to corrode and fail with the appearance that the heads have sheared off. If the trailer has been setting next to the salty ocean air for as many years as you have stated, then I wouldn't be surprised that you have corrosion problems.

I have seen this on many Aircraft and Airstreams in my career.

[KellySLC49]

Aerowood, what do you suggest to remove the white powdery corrosion, he's talking about and stop its progression? Ours is inside between the body and various panels. Our Bubble grew up near the ocean too, in the Pacific Northwest. The body is off the frame right now, so we're in better shape to access it. We have to replace the side of one upper cabinet since the entire aluminum face flaked off!

As far as sealing, we've used Captain Tolleys creeping crack cure from Vintage when the only access is from the outside, but I agree you should see if there's frame damage allowing too much movement.

[Aerowood]

The only sure way to get rid of it is to replace the corroded skin, but this is an extreme option if the skin is rotted completely through. Second best is soda blasting. The other option is to clean with a scotch bright as best you can and live with it. If you clean with alumaprep on the corroded area after you think it is all gone then any corrosion remaining will show up as black spots. Its a judgment call as to how far you want to go with it. Be sure to seal the lap back up real good before riving back together.

Moisture and salt do not play well with raw aluminum. If Airstream would seal all the mating surfaces these problems would be minimized.

There's no miracle solvent or cleaner to clean up corrosion.

[KellySLC49]

Thanks Aerowood! I figured a good scrubbing/sanding was required. I was hoping there would be some type of neutralizer or the equivalent of a rust converter, but for aluminum. I'm replacing all that can be seen, like some of the upper cabinet faces, but most are down low where water seeped in.

Thanks for your input!