Under Panels

[jperryfly]

Does anyone know what thickness and type aluminum to replace panels underneath trailer with? I was thinking 6061-0 in .025 thickness.

[InsideOut]

What year is your trailer?

Shari

[jperryfly]

It's a 31' 1985 Sovereign.

[jperryfly]

Did I say something wrong?

[InsideOut]

No, sorry...I just can't help. I only know the vintage stuff...maybe someone else knows or can help.

Shari

[Ken J]

Yes you called them panels rather than belly pan aluminum - just kidding

Anyway - the aluminum used is 2024 T3 - non alclad - if I remember the older trailers used .032 and the newer ones .025.

Ken

[jperryfly]

OK that gives me so good info. I still think I'll use 6061 or 5052 they have much better corrosion resistance than 2024, and they are cheaper too!

[Over59]

OK. I'll take the bite What do those numbers mean. And what is the stuff inside.

[jperryfly]

Those are alloys of aluminum. 5052 is a common commercial grade and 6061-T6 and 2024-T3 are more common to aircraft. The letters and number suffixed are heat treatments. -0 would be annealed or soft no heat treatment. 2024 is much more expensive than 6061, and is normally "alclad" or coated with pure aluminum to resist corrosion. 6061 and 5052 are pretty corrosion resistant already and don't need the alclad. I don't really know all that much about it but you can read more if you get an Aircraft Spruce and Specialty catalogue. The "spruce" in the name came from days when wood was more popular in aircraft building. A 4' x 12' sheet of 6061-T4 .025 thick is $55.50 while the same thing in 2024-T3 is $152. I think 6061 is fine for "belly pans".

[greg176]

I have read that they only used 2024 on older units.My '61 is all 2024 as evidenced by the severe corrosion in the belly pan and "U" channels.I think that Airstream switched to a commercial grade aluminum in the late sixties,probably a 5000 series.Thanks for the heads up on the price I was getting ready to buy about 12 sheets of 2024 and knew the 5052 was cheaper but never looked.Maybe I'll use 5052 for the belly and interior and will only need 3 sheets of 2024 for sides.

[greg176]

Another good source for metal is:
http://www.airpartsinc.com/

[jaco]

Good thread, good information, good to know.

Still would like to know more about the different types of aluminum and their pluses and minuses.
Are there literally thousands of varieties (sure hope not)?

Is alclad coated on both sides? Seems odd that aluminum sheeting would need to be coated with aluminum.. I wonder how that coating is done? Must be applied after the original sheet is completed? No?

Anyone know if the Spruce Co. Catalog is online (PDF maybe) by any chance?
Just interested now in the aluminum sheeting explanation page/s.

[greg176]

Here is the link to aircraftspruce aluminum info page.

http://www.aircraftspruce.com/catalo...s/aluminfo.php

Yes alclad is coated on both sides and the coating is only about 7 mil thick.The copper in 2024 gives it it's high strength but makes it VERY susceptible to corrosion so it is coated with pure aluminum to protect it.If the alclad is scratched the aloy is exposed an will corrode.
I have not seen a definate answer as to what aluminum was used on later Airstreams but suspect they are made of 5052.

[Ken J]

Hmmmm, learning something here - so what is the difference between the 5000 and 6000 series - sounds like it would be better for the belly. I assume you can get it in the same thicknesses as 2024 and I assume that its as easy to work with??

Ken