Hi all, wondering if anyone can help me out with a problem I'm having whilst welding aluminium.
I'm using a made in China TIG machine, just about the cheapest you can get which will also do AC from the brand Vector Welding. When I weld aluminium on AC the arc extinguishes all the time. On DC the arc does not extinguish.
Often it extinguishes almost instantly, before it even stabilises. It also seems to often extinguish whilst adding filler (maybe because I'm moving the torch away to prevent dipping the tungsten, which might be increasing arc length). It also has a really hard time reigniting an arc on any area of the workpiece which already has some frosting from the cleaning action, ie. reigniting on a weld restart.
Has anyone else had a similar experience? As far as I can tell from research, the arc is going out because it's rectifying. I just wonder if there's anything I can do to make it happen less.
Things I have already done:
- checked both leads for good electrical connections
- put ground directly on workpiece
- tried AC on other materials: on steel with aluminium bronze AC 90% EN the arc is stable
- experimented with gas flow, no obvious difference within reasonable range (10 - 16 CFH on #5 cup)
- experimented with frequency and balance, best at 80 Hz and 80% EN. Frequency too high or too low makes things pretty unstable
- tried different tungsten (ceriated, lanthanated, always very cleanly prepped), all seems the same
- tried a #5 gas lense, surprisingly way way less arc extinguishing than with a standard #5
- tried foot pedal and on/off switch
Really appreciate it if anyone has some advice!