Guys. I am a certified welder for arc welding and autogenic welding and brazing. While my education focused on welding iron metals only, I had the joy ones to work with aluminum too. To say it simple, working with aluminum is not easy. In my eyes it is impossible to assure that a welded aluminum joint will have the same strength as before.
Any weld will take away the tempering qualities of the material as well as the composition of the alloy itself. Usually the material will crack again in the area where the heat was not sufficient enough to affect the temper. You are creating basically a soft area within a hardened area. I would not put my life onto a welded spar, unless it was originally produced and tested that way. It is a different thing though for structural pieces on an airplane that had been welded in its original production process. The extra strength needed is calculated in the size and the number of the pieces used. A repair to a cracked weld on an engine mount is ok, because that is the way the engine mount had been build in the first place. Hartmut ----- Original Message ----- From: [EMAIL PROTECTED] To: [email protected] Sent: Sunday, February 17, 2008 6:55 PM Subject: [ercoupe-tech] Re: Crack Spar Regardless of the confusion over where these cracks are forming, I think the notion of a welding repair to an aluminum structural component on our aircraft is interesting. I would not be so quick to assume that there is a government obstacle to such repairs. My motor mount has a 337-documented welding repair. Though not structural, I have also seen several of our oil tanks showing evidence of cracks around the upper flange which were repaired by brazing. There may be formidable physical problems though. I’m not so good at welding aluminum, but folks I’m learning from tell me that 2024 is not an ideal alloy for welding. Also, how the heat and physical presence of the weld would effect the overall dynamics of the structure would need to be considered. I would be interested in hearing the opinions of more accomplished welders. Cheers, Bill ------------------------------------------------------------------------------ More new features than ever. Check out the new AOL Mail!
