Originally Posted by kalanic
Very good advice! I can tell you as a welder by trade & a Certified Weld Inspector from the American Weld Society that a repair like that will have to be done by a MIG machine or Oxy-Fuel Welding. GTAW (TIG) will not work because of the thickness of the aluminum. You will risk opening up the repair to much causing it to be much worse. It looks like a fairly simple repair. As Sporty stated, you will want to to add extra filler metal beyond the repair & possibly tie into the existing weld. Make sure your welded does a Liquid Penetrant Test (PT) on the repair & I would also request to Test the rest of your welds to verify there are no other stress cracks. Good Luck!
Interesting, thanks for the info. I do a lot of TIG welding on mild steel, but I can't weld aluminum worth a sh** with it. I understand the theory, but my attempts have been pretty funny. I only know enough to be certain that that crack is going to be a tough one to fix well, and that New Dimensions should step up.