[Bill Beauregard]

Outside corner joints in thin aluminum for me work best with filler, For 16 gauge I fit very tight, tack at 1" intervals, then either pulse with my right foot or machine pulse. I use 3/32 4043Pulsing gives time for the aluminum to not sag, yet I can get enough heat into it for good penetration. The outside corner looks good, It all goes wrong when I then go inside and try to turn the bead that forms into a fillet weld, Invariably this causes parent metal to sag away from the nice clean stack of dimes. The original bead might be 1/4" wide, but the melt away might be 1/8" wider than that. It's sort of a dilemma, I'd like the reinforcement and to have pretty welds on outside and inside corners, but that doesn't work very well.