01-09-2018, 07:32 AM
Actually, 90% of the aluminum that I have ever worked with has been 6061-t6 and I have never had a problem. Though I have never used 3003 before I can tell you that the reason that most extruded pieces are 6061 because of its strength, ease of welding, and overall workability. If what I have always heard was true, then aluminum does not get brittle from welding, either, but instead gets "softer". Actual physics escape me at this time, but I believe that you can expect any welds on aluminum to be weaker than that of the parent metal because of this. Do not get me wrong, I am by far no professional like you will find others on here are, but this is what I have encountered personally in numerous and extremely off the wall jobs (this includes everything from frame rails for prototype tractors to home-made popcorn poppers). Anyway, there are some great websites for weldability and workability info, and a simple search should reveal them should someone else not reply readily with them. Hope that helps!