Root Penetration/ Base Metal Fusion on Aluminum Welding 1/8" 6061 cupons (very clean: scotchbright and acetone wipedown). No edge prep but welds and fillet welds single side. Tig, 150 amps, 70 Bal, 80 Hz, 3/32 Pure tungsten (balled), 3/32 4043 filler rod (also very clean). Pure argon, 17cfm. garage temp is 60 degrees, no preheat. I am getting shiny proud beads with good fusion at the edges of the bead (inside the cleaning zone) reliably, but whenever i do a single side break test, i notice that (it always breaks on my weld, and the base metal is sometimes slightly melted but never fused, even when the two plates are showing slight melting on the far side). I have fiddled my settings a fair bit and tried to play with travel speed etc, but cant get an aluminum root to fuse for the life of me. I can't seem to find root etches or much discussion about root for aluminum.... is it different than steel as far as root penetration and base metal fusion or am i just failing?…