Welding aluminium/Kempotig AC/DC250

[ChopperBuilder]

Hi, haven't used my welding gear for nearly 2 years and was an amateur then (and even 'lost' that now I feel) but started to make some decent looking aluminium welds. Had only got the Kempotig then as well. Trying to get back into it and can't say I'm having much luck yet, Can someone advise whether I'm on the right tracks as I have a job to do neatly with it waiting:

-am finding current setting about 75/80A AC may be right for 3mm thick aluminium to both melt the surface but not blast it away?
-am using 1.6mm Zirconiated white tip electrode
-pure argon shield gas at 5psi supply
-AW-4043 filler rods

Even trying to lay down some bead runs on clean bar isn't going to well and the electrode seems to be burning back very quick. I am letting it form a round ball on the end of the tip.
Any advice much appreciated, or directing to an area of this forum that may provide a guide for the likes of me !
Cheers, Joe

 

[shenion]

I'd try a 2 or 2.4mm electrode.

 

[Shox Dr]

Hi Joe. Plenty of people in the same boat, so it's been asked many tomes before, no need to search just scroll through the TIG pages and you'll find tons. As usual the first thing we ask for are pictures.

 

[wheresmejumper]

adjust the ac balance to less cleaning,should fix the tungsten eroding

 

[Georgie]

Have you tried any other tungsten than zirconated?

 

[pedrobedro]

Get some ceriated or lanthanated tungsten and you need to know the flow rate of the argon not the pressure. You may be too low for cover at 5psi.

 

[ChopperBuilder]

Gosh, thanks for so many useful replies - I will try again over the w/e and report back.
Cheers, Joe

 

[ChopperBuilder]

well, some progress today, couldn't get any alternative tungstens yet being bank hol w/e but adjusted AC balance right down to -3 (scale goes from -5 to +4)which certainly stopped electrode burning away ! Had to increase amps to about 110 (to compensate ??). Checked flowrate as about 8cuft/min (I need to check flowgauge units), made sure I stainless steel brushed joints and washed with acetone. Pics show something going in the right direction but obviously not too pretty yet (seen alongside original pro welded fillets). I'm trying to put a stiffening tube as extra support on this frame as there has been some bending. Getting some spitting/spatting from electrode but 'seeing' process better through mask now as well. Any advice from here ? Many thanks