Miller multimatic 220 tig cuts in and out

[Nnorman1]

The tig on my welder was working great while I was welding aluminum until all the sudden it wouldn’t arc right anymore and the tungsten just balls up, it’s getting good gas flow, I even swapped out the tank because the last one started to get low.
It will just cut in and out bad now, not sure what to check.

Any help would be appreciated

[adbuch]

Have you accidentally revered polarity?

David

[weldguy]

I my experience with welding aluminum with tig you want the tungsten to form a little ball on the end. I have had problems in the past where I accidentally tried to weld aluminum with the tungsten I use for steel. What tungsten are you using for your aluminum welding?

[adbuch]

I my experience with welding aluminum with tig you want the tungsten to form a little ball on the end. I have had problems in the past where I accidentally tried to weld aluminum with the tungsten I use for steel. What tungsten are you using for your aluminum welding?

This all depends on your welder and tungstens. With my Miller Synchrowave 300 (transformer model new in 1984), in the old days I would use pure tungsten for aluminum with the end balled using reverse polarity. Then straight polarity AC for the actual welding. These days I use either 2% lanthanated or 2% ceriated tungstens with that machine for welding aluminum. With those newer tungstens, no need to ball the end - just start with a slightly blunted sharp point and it will form a small ball automatically as you weld. For that same machine, I use 2% Thoriated for steel, stainless steel, etc.

With my newer Miller Dynasty 350 I use the 2% lanthanated for aluminum and 2% Thoriated for steel. It will work with the lanthanated or ceriated tungstens for steel, but the tungsten stays sharper longer with the Thoriated.

When I started using the lanthanated or ceriated tungstens with the older Synchrowave 300 for aluminum, it was like a whole different machine (greatly improved) when I made the switch from using the pure tungstens for aluminum.

David

synchrowave.jpg

dynasty.jpg

[TJS]

I use the Lazyr tungsten or whatever it is called. I leave it sharpened when running alum on my dynasty. Some people ball the end on purpose some don't, there is probably thousands of different opinions on why and why not to ball the end. I just leave it sharpened and if I am welding a long time it will start to form its own ball. To the OP. Might want to post you issue on the miller board. What are your settings.

[adbuch]

TJ - the lazyr tungsten is one I had not heard of before. It gets pretty good reviews on Amazon. Yes - with my Dynasty I do more or less the same as you for aluminum. I leave it sharp (with a very slightly blunt tip) and it balls up as you weld with it. I'm using either the ceriated or lanthanated for aluminum. I'll have to give the lazyr a try.

Thanks,
David

[TJS]

TJ - the lazyr tungsten is one I had not heard of before. It gets pretty good reviews on Amazon. Yes - with my Dynasty I do more or less the same as you for aluminum. I leave it sharp (with a very slightly blunt tip) and it balls up as you weld with it. I'm using either the ceriated or lanthanated for aluminum. I'll have to give the lazyr a try.

Thanks,
David

Sounds good. Oh and try the Hobart 4943 filler. Creamy if you know what I mean. It is my go to filler for alum.

[adbuch]

TJ - the lazyr tungsten is one I had not heard of before. It gets pretty good reviews on Amazon. Yes - with my Dynasty I do more or less the same as you for aluminum. I leave it sharp (with a very slightly blunt tip) and it balls up as you weld with it. I'm using either the ceriated or lanthanated for aluminum. I'll have to give the lazyr a try.

Thanks,
David

Sounds good. Oh and try the Hobart 4943 filler. Creamy if you know what I mean. It is my go to filler for alum.