1970 New to us Ambassador reality check

[Aerowood]

An “AD” rivet is a rivet made with 2117 aluminum. It’s a significant jump in shear strength then the “A” rivets that Airstreams are made with. “A” rivets are made of 1100 aluminum. The only place Airstream used AD rivets on the 70’s trailers was on the lower skin to C channel and the front hold down plate.

[Aerowood]

To identify an AD rivet look for a dimple in the center of the head, an A rivet has no identifying marks on the head.

[Minno]

Thank you Kip! We had not heard of that rivet before now. Probably should have used some when we put our trailer back together. Oh well.

Kay

[2002sheds]

Kip,
I gotta ask... is that you or Sir Richard Branson standing in the back of that plane with the hatch open?


David

[2002sheds]

Hi All,
The more interior skins that come off, the more Olympic (at least I think they are Olympic — I don’t know the difference between them and Cherrymax, in function or appearance) rivets I am finding... like the entire curb side, including windows. There already are “elephant ears” on the rear from a floor repair a while ago.

Was there ever a point (our coach was built in 1970) where AS was using blind rivets in production? These outer skins do not look at all new, but the coach is 50 years old this year, so I guess it is quite possible that they “aged” after the repair, if that is what happened.

I don’t know much about the history of this Ambassador after the early 1990s. That seems to be when the original owners sold it. I have had some contact with the original owner. If it has that much work, I think it would’ve been mentioned, but maybe not.


Confused in California,
David

[2002sheds]

Hi All,
Okay, they are definitely not Cherrymax. They seem to be Olympic rivets, many hundreds of them...


Thanks,
California David

[wcronin4]

David

I’m pretty sure AS did not use Oly rivets in the manufacture of your Ambassador. I’m guessing the cost alone would have prevented extensive use. For example, Oly rivets retail for $.25 to $.35 apiece. And a bucked rivet, in my opinion, is stronger and less likely to fail during installation.

Oly rivets would indicate a repair of some kind. If your finding them where the outer skin is tied to the channels along the bottom, it might indicate that the shell has been lifted off.

Perhaps someone else will have a different view, but they indicate a repair or they are used to install an accessory to the outer skin where bucked rivets are impossible to install with the inner skin on.

For example, I just removed two vista windows from my AS and used Oly rivets to install aluminum to cover the holes. I did so because I couldn’t get access with a bucking bar. So it was a repair.

Sounds like your sleuthing it out, though. You’ve become an archeologist.

[wcronin4]

PS David

Another factor arguing against Oly rivets installed at the factory is the amount of time it takes to install them. First the have to be installed. Then the mandrel nipped off. Then the head shaved smooth. That doubles the installation time of one rivet. Multiplied by thousands of rivets used it would be cost prohibitive.

[2002sheds]

Hi Bill,
Thanks for the replies! I tend to agree with you, and I could not find any references at all on Air Forums either. Your explanation makes total sense -- why would AS spend all that time (money) to do things that way?

Unfortunately, that leaves me with even more questions. What happened to this coach that not just the lower exterior panels but the next row up were replaced? By all accounts, it has spent its life in the greater Sacramento, CA area. Not exactly a corrosive environment... and no signs that a tree branch fell on it (not that I could really tell).

If my far from experienced sleuthing is at all correct, it means that nearly 40% of all of the exterior panels have been replaced. And that is with just one side of the interior skins removed. That number could increase dramatically.

There is not evidence of other damage (like repairs made to the ribs) and the ribs certainly look old, but even more excitement may occur today when I get the center strip of interior skin out.


Thanks,
California David

[2002sheds]

Hi All,
More of the answer to my mystery AS is starting to reveal itself, and not necessarily in a great way... and all of this started because I am trying to make sure that there is a positive connection between the ribs and the frame.

I have now removed the center interior skin and all of the skins on the curb side of the coach. Olympic rivets fasten the first 3 panels up — in other words, up Onto the roof, past the point where the awning attaches.

After pulling away the fiberglass wall insulation in several cavities, I could begin to see the difference — not just because of the presence of the Olympic rivets versus bucked rivets, but because of how much brighter the “newer” aluminum is...

Unfortunately, it appears as though at least some of these Olympic rivets have leaked (picture below, for confirmation or denial. There is also a picture of the coach in its present miserable state and one of a previous attempt to tie a rib to the C channel. Sorry about the orientation...).

I can now see why so may of these coaches are brought along to this point and then sold. This is scary in scope, especially since I am inclined to follow Aerowood’s path and re-rivet all of these panels... when I recover from this disappointment. I REALLY don’t want to go though this much effort, only to have leaks — especially in multiple places, as this seems to possess.


Color me intimidated,
David

[Minno]

There are ways to seal these rivets without replacing if you REALLY don't want to replace them. Parbond, Sikaflex, and Trempro 635 are all relevant to this, and many people reseal from inside before putting interior skins and insulation back up. Personally, I would seal them from the inside with Trempro, and then do a water test BEFORE putting the insulation up to ensure they got sealed. If not sealed, then I would use Parbond or Sikaflex from the outside to seal, and test again.
As I have said before, we have Olympic rivet repairs on our trailer, both before we bought her and since we've owned her. Our front lower panels were both replaced before we bought her, Olympics were used (by someone), and have never leaked. We Trempro the hole before we use Olympic rivets in them. And we don't use the gasket that comes on some of them. Those can fail.
I respect bucked rivets, but I understand how intimidating your repairs are if you actually contemplate replacing all those rivets. Ye gods and little fishes!

Kay

[2002sheds]

Hi Kay,
Thanks so much for the reply! I have been “wandering in the wilderness” a little bit...

I appreciate the advice about how to seal the Olympic rivets. I should have been more clear that my preference is to get rid of them, now that the inside is opened up.

My hesitation is that, having never set rivets before, I don’t know if it is inadvisable to do so, especially if the Olympic rivets already have a 5/32” shank. I do have a stash of Modified Brazier Head rivets, but what if the holes are larger?

Any advice will help my nerves settle down...


Thanks,
David

[2002sheds]

Hi Kay,
Thanks so much for the reply! I have been “wandering in the wilderness” a little bit...

I appreciate the advice about how to seal the Olympic rivets. I should have been more clear that my preference is to get rid of them, now that the inside skins are off. I am nervous that the holes will be too big for the 5/32” Modified Brazier Head rivets...


Thanks,
David

[wcronin4]

David

You are at the point I was when I fully understood what poor condition my AS was in. And I was faced with having to replace the frame...at 72.

I don’t regret taking the project on.

After I had time to recover from being disappointed at my AS’s condition, I said to myself that I’ve never walked away from a challenge and at the time I had nothing better to do. Now there is a certain amount of pride at seeing where I am in comparison to where I started.

Bucking rivets is quick and easy and the tools are relatively inexpensive. The good thing about removing Oly rivets is center of the head is the mandrel. If you tap the center of an Oly rivet with a center punch or auto-punch it drives the mandrel in and gives you a hole to orient your drill. If your concerned about using the modified 5/16 rivets, order ones with a standard head. Yes, the heads may be larger than original, but if you do a proper job, they won’t be noticeable.

Is it possible from the location of the Oly rivets if your Ambassador was in a accident?

What ever you decide to do, there is nothing in your project so far that is beyond your ability. You can do this!

[2002sheds]

Hi Bill,
Thanks very much for the encouragement, advice and perspective! It is helping me move forward. I was very much stuck...

On a whim, I decided to try to cut off the backs of the Olympic rivets with a Dremel tool, rather than drill them. My fear with drilling them is that I will enlarge the hole, which is already 5/32”.

It worked! I was getting good enough at the task that I switched over to an angle grinder equipped with a metal cutting disc. I removed the remainder of the rivet by popping it a few times with a spring-loaded center punch. It drives them right back out the way they came in. I have already removed the curved Vista View window in the stack by the front door, without incident.

As the pictures show, it is probably a good thing that I am removing these. A LOT of them have leaked. I don’t want to count on a sealant applied to the inside to prevent water intrusion. Like you said, I’d like to only do this one time.

I did get a rivet gun, and I have a supply of 5/32” Modified Brazier Head rivets. Aerowood encourages me to start using this tool. Looks like I will get plenty of practice!


Thanks,
David

[tx70amb]

David it has been about 22 months or so since I have posted on the thread. I t sure is good to see you are still at it. I know multiple postings from Aerowood helped me through the process and it looks like Bill is giving you some great tips currently. This is a post of encouragement to keep it up. I want to see another 1970 Ambassador on the road. I will pipe in when I can add to the thread but so many more capable are already doing so. Onward my fellow AS friend.

[2002sheds]

Hi TX,
Thanks so much for the response! I am glad that you were able to get back on here — the timing could not be better, as I can use all the encouragement I can get after the last few days.

The initial disappointment is giving way to lining up the steps to accomplish these tasks. Today I was able to remove one of the Vista View windows, and that definitely gave me an idea of the method to remove these Olympic rivets while preserving the existing hole as much as possible.

A lot to do, still... but I am gonna stick with it. And I am also looking forward to getting this coach back together and eventually on the road !!!

Thanks again, TX! Stay safe out there!


California David

[Aerowood]

Originally Posted by 2002sheds

Kip,
I gotta ask... is that you or Sir Richard Branson standing in the back of that plane with the hatch open?


David

That's me

[Minno]

So glad you found a good way to get out the Olympic rivets!
I would still do a water test on the whole trailer before you put insulation and inner skins back in. We found several seams that needed resealing that way.

Kay

[2002sheds]

Hi Kay,
I thought of you as I pulled the interior panel and find two pop rivet holes in the vent pipe in the galley...
And I will definitely follow your advice about the water test. There is too much work involved not to.

Thanks,
David