On Sat, 14 Jan 2012 19:43:36 -0600, Richard
wrote:

On 1/14/2012 11:53 AM, Ed Huntress wrote:

Regarding O/A welding of alumnimum, it's tricky. I've tried it but not
enough to be any good at it. There's no red color of the metal to
guide you. It just goes "shlump" all of a sudden. But it's a neat
skill to learn. A lot of airplanes were built from O/A-welded
aluminum.



Ed, I don't often feel confident enough to call you on metalworking, but
this one is a cinch.

I have NEVER seen a welded aluminum airframe.

The skin, brackets, and tanks, Richard. Not the frames. But those
pieces were still life-critical jobs.

When O/A was used in commercial production of aircraft, the frames
were not aluminum to begin with.

O/A was used until the 1940s for many aluminum aircraft-welding jobs:

http://metalshapers.org/tips/white/a...ding/index.htm

http://tinyurl.com/7bjbxso

I couldn't find any references but I remember from my _AM_ days that
Northrup pioneered all-welded aircraft. Frustrated with how slow O/A
was, they developed early versions of TIG.

But they made aircraft with O/A prior to that, with few rivets
anywhere.

--
Ed Huntress




Lots of OA welded 4130 tube, but never aluminum.



Richard