Sheet Metal Forming for Aircraft skins

[tfindlow]

Hey There from Charlotte, NC. New member - interested in forming complex curves in sheet aluminum for aircraft skins. My searches kept coming back to AllMetalShaping.com - so I figured this is where the Knowledge is...

[rivetdriver]

welcome to the forum.
What exactly are you trying to make?
happy holidays

[longyard]

Tim,
A/C skins are usually make from 2024 aluminum which often requires heat treating after compound forming. Most of the aluminum work you'll see on this site is done with 3003 or 1100 aluminum. The latter two are very weldable. 2024 is not.

You'll learn a lot here as we have some great a/c workers here. However, don't mix up the alloys.

[AllyBill]

Originally Posted by longyard

Most of the aluminum work you'll see on this site is done with 3003 or 1100 aluminum. The latter two are very weldable. 2024 is not.

No one told me that until quite recently and by that time I'd been welding 2024 with great success for many years. It welds like any other grade in my experience.

Will

[crystallographic]

Hi Tim,
Welcome.
Hope we can help.

I was an EAA tech counselor for many years, on sheet metal and welding.
Aircraft over the years have used 1100, 3003, 5052, 6061, 2024, and 7075.
Some shaping is done in T-3 on the 2024.

[Jere]

Hello Tim and welcome to the forum.

Jere

[longyard]

Originally Posted by AllyBill

No one told me that until quite recently and by that time I'd been welding 2024 with great success for many years. It welds like any other grade in my experience.

Will

FAA Advisory Circular 43.13-1B, Ch 4, Para 4-89, d, "AIRCRAFT PARTS NOT TO BE WELDED".

d. Nos. 2024 and 7075 Aluminum. Do not
weld these two aluminum alloys (that are often
used in aircraft construction) because the heat
from the welding process will cause severe
cracking.

[AllyBill]

Not welded 7075 so can't comment there.
2024 can crack if you weld it in one of its higher tempers depending on what you are trying to do, don't for instance try to insert a circular patch, but when properly annealed it welds like any other grade and doesn't crack at all. When I say properly annealed I mean you take it to the heat treatment plant and have them do a full anneal and furnace cool, make your weld with strips of native material then have the heat treatment plant put the desired temper back. Never had a problem with it.

As a slight aside, the skins of the Handley-Page Victor wing were extensively spot-welded with no issues and they were 2024.

Will

[sblack]

Try to find copies of two videos by John Glover. Aluminm Shapes and Aircraft Shapes. They are old and were only put out on VHS but found mine on ebay. Also Kent White's videos called Shrinking Magic and Shaping Aluminm Wheel Pants and his Aluminm Welding videos (TMTechnologies.com) taught me a lot as well.

Much of the compound curved parts on light aircraft are fairings and not load bearing, so they are commonly made from 3003 which is easy to weld (If I can do it, you can) with a torch. There are some good threads here and on that metal shaping site on aircraft work. Good luck.

[KAD]

A very good read on what can/should be done with the different grades of aluminum. Also included is a complete description of the numbering systems and what alloys are used and why.

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


*Note: Spot welding is OK vs. arc/torch welding with some alloys....like 2024
It doesn't say that it can't be welded it says that it shouldn't be as it leaves the metal in a state prone to failure.
The word "Failure" when used in conjunction with "Aircraft" should be avoided as the phrase "search for the Black box" usually follows.
Likely a "proper application" question as opposed to a "can it be done" question......