Alclad?

[Sburg58]

I have a 1965 Safari, the wheel well and lower exterior aluminum was damaged by a blown out tire. The local airstream dealer says he can repair the exterior damage with aluminum they have in stock, he says it is the latest type aluminum that Airstream uses and it comes with a plastic coating already applied. I have been told the 1965 used alclad aluminum and I am wondering if this latest Airstream aluminum is alclad? I can get a sheet of alclad from several sources, the dealer is willing to use it instead of his stock supply. So is the original aluminum on a 1965 alclad, is the latest from Airstream, alclad? He was not sure and neither am I. This trailer has been partially polished, so I would like it to be restored using what ever was original.

Stan

[Cochese]

Yes, it originally had alclad. Not sure about new A/S using alclad, I know it's a different"grade" of aluminum. Btw, having done a side panel replacement on my 63 Globetrotter, it's no small task!

[Gregsch]

I bought some alclad from VTS for a repair to my 1979. When I polished it, it match perfectly.

[Silverflames]

It's my understanding that they are different metals, and the "newer" metal will not match and will not polish the same. VTS appear to know their stuff, you can go with them. I'm sure others will jump in with the exact metal type and number.

[dbj216]

Your 65 has 2032-T3 Alclad aluminum at .032 thick. This is a very good grade of aluminum. Airstreams used this alloy until the early 80s. Yours may be still coated with the "plastic coat" Airstream used to try to protect the aluminum from corroding to a dark gray. It lasts about 20 years before it starts to weather off.

Alclad aluminum is still manufactured and still readily available. I purchased mine from Air Parts in Kansas City. It will cost about $17 a square foot. It is expensive material.

Newer Airstreams since 1999 use a "baked on" polymer coating that is extremely durable. It is .040 thick accounting for the larger body and additional weight of the newer Airstreams. The new trailers look great with it.

Your dealer or repair shop can repair your trailer with Alclad sheeting. Here is a photo of the patch I made using Alclad for my trailer next to the door. The trailer has since been polished so it is as shinny as the patch.

David

[Aerowood]

dbj216 mis-stated the alloy number by a couple of numbers. Your coach was originally sheeted with 2024-T3 .032 Alcad. I would replace it with .040.

[Sburg58]

Thanks for all the prompt replies. I have found 2024-T3 locally, they quoted the .040 at $4.61 a square foot plus a one time $16 cutting charge, if less than a 4ft by 12ft sheet. Aerowood, they also have .032, so go with the .040, only .008 thicker, more robust, just as easy to work with? Dealer says he will use the alclad.

[dwightdi]

Alclad is actually a laminate of three sheets of aluminum. The middle is the 2024 - T3. The two surface layers are straight Aluminum. The 2024 is a higher strength alloy and the T stands for the heat treatment. 2024 was first used on planes by itself, but has poor corrosion resistance, as they found out with the airplanes on aircraft carriers during WWII. Alcoa invented Alclad with more resistant pure aluminum on the surfaces, The pure aluminum takes higher shine and will not dull as fast. The latest Airstreams come with a brushed finish and a UV cured plastic coating that is applied as the sheet is produced at the mill.

[Aerowood]

Originally Posted by Sburg58

Thanks for all the prompt replies. I have found 2024-T3 locally, they quoted the .040 at $4.61 a square foot plus a one time $16 cutting charge, if less than a 4ft by 12ft sheet. Aerowood, they also have .032, so go with the .040, only .008 thicker, more robust, just as easy to work with? Dealer says he will use the alclad.

The .040 will lay a little flatter and not dimple as easily when shooting in solid rivets. As you said "more robust and just as easy to to work with". I replaced most of my skins with .040.

[dbj216]

Thanks Aerowood for the clarification. I should have said 2024-T3. And the price at Air Parts is $16.75 per LINEAR foot. I bought it in a 48" wide roll, so one foot of length equals 4 square feet, or about $4.00 a square foot. I have had good experiences with Air Parts out of Kansas City.

I used .032 as that is what the original material was. I didn't have a dimple problem as I used those Olympic tri-fold blind rivets. They don't have just a lot of grip compared to a solid rivet and a "bucking bar".

David

[Sburg58]

Well, the problem continues, the dealer and I measured the side panel that needs replacement, it is 75 inches long and 50 inches wide. The side piece, just rear of the door, wraps under the trailer then meets the belly pan. The problem is I cannot find any alclad that is 50 inches. Of course the standard is 48 inches, which I can get locally. Suggestions welcomed.

The 5052 alloy is available that wide, however I am thinking it will not match even if polished?
The Safari is pretty shiny having been polished, I believe with just the first step/grit. It was done a while before my purchase, some of the original "plastic" coating is still intact however it is peeling a bit.

Stan

[dbj216]

One suggestion if I may. Our mid sixties trailers have that "belly wrap" that wraps all the way under the trailer. My 66 Trade Wind has a steel strapping along the outriggers where this wrap is riveted to the to the belly sheet. The attached photo shows this strapping between the outriggers. You can see the side panel hanging down. I had removed the belly aluminum to repair a rotted bath floor and inspect, paint the frame, replace the floor insulation, and replace the belly aluminum.

It seems to me that it would be possible to simply extend the 48" wide Alclad side panel sheet with a 2" piece of belly sheeting. Having another rivet line on the bottom of the trailer wouldn't be a bother to me. Make the extension long enough to reach the strapping. I think simple pop rivets would be fine in this area. That is how the belly aluminum is attached to the strapping. You want the splice to be strong enough to hold the side panel wrap tight.

David

[Nuvite-F]

Originally Posted by Sburg58

Well, the problem continues, the dealer and I measured the side panel that needs replacement, it is 75 inches long and 50 inches wide. The side piece, just rear of the door, wraps under the trailer then meets the belly pan. The problem is I cannot find any alclad that is 50 inches. Of course the standard is 48 inches, which I can get locally. Suggestions welcomed.

The 5052 alloy is available that wide, however I am thinking it will not match even if polished?

Stan

Stan,

As dwightdi explained earlier, Alclad sheet has a base layer of the specified alloy (2024-T3, 5052-H32) with a few thousandths of an inch of pure aluminum on the surface for corrosion resistance. From the standpoint of us Airstreamers, Alclad takes the best polish and the bare aluminum surface has the best corrosion resistance.

Currently produced Airstreams are made from 3003 - O (not Alclad) which is mechanically weak compared to 2024-T3. But 3003 is nearly pure aluminum to begin with, so it has corrosion resistance pretty close to Alclad sheet. My guess is that 3003 would probably polish up to match Alclad pretty well.

The difference in strength is dramatic. Referring to my trusty ASM Metals Reference Book, 3003-O has an ultimate tensile strength of 16,000 PSI whereas 2024-T3 has an ultimate tensile of 70,000 PSI, more than four times as much. So you would probably want to use thicker sheet than the original .032.

5052 is a little higher alloy than 3003 but still has good corrosion resistance. I suspect that 5052 would polish up close enough in appearance to Alclad that nobody would notice the difference.

Another popular aircraft alloy is 6061-T6, 42,000 PSI ultimate tensile, not as strong as 2024 but getting there, and available in Alclad. If you can find some 50 inch wide 6061-T6 Alclad I would go for it.

And as dbj216 points out, you could "piece" the sheet you need with a doubler and an extra rivet line which probably no one would notice unless they were looking for it. I would definitely recommend bucked rivets for the splice; which could easily be done on the bench before the sheet is riveted to the ribs.

For a good one-page tutorial on aluminum sheet see Aircraft Spruce's web page,
http://www.aircraftspruce.com/catalo...s/aluminfo.php

Good luck!

[Sburg58]

We have decided to replace with 2024 T3 alclad. We will do as dwightdi suggested, rivet an extra piece to extend under the trailer. I appreciate all the expertise , help and suggestions from everyone. It is very nice to have a site which has such a large supply of very knowledgable individuals. Thanks to all.