Looking for some tips, machine is an older syncrowave 250. When welding thick aluminum (like 1/4"), at 200-250 amps, the arc kind of "pops" and the puddle pushes and ends up sort of concave, like the gas pressure is set way too high. It's hard to describe. Tried adjusting balance and frequency a little, without much change. Seems like it's better with the balance all the way up, but still does it. Haven't messed with the frequency much. Grounded directly to the workpiece. On low amps it is fine. Any ideas?

 

might be running to many amps for the tungsten.

 

Yup, try thicker tungsten.

 

forgot to mention that is with 1/8" ceriated. Could it be the ceriated tungsten? I think I remember reading it doesn't like higher amps

 

you ever hear of Tungsten Spitting ?

 

I thought that was when the tungsten melted into the puddle

or is that what is happening? doesn't seem like it

 

no not rly.. at High amperes the arc becomes unstable on ac using ceriated

Ceriated is best for carbon and SS

But try Zirconiated or Rare earth

 

makes sense, I'll try a different tungsten thanks

 

1/8 zirconiated should be perfect for what you're doing. Ceriated works great with inverters though.

 

try spending more time building heat in the material before you start feeding filler or preheat it.

 

yeah clamp some thick Steel on the back side for a heat sink too

 

that's not the problem I've used other machines in the same application just fine. I can't build enough heat because the arc starts popping. I'm going to try another tungsten hopefully that is the problem

 

It's because it is a transformer machine, and for whatever reason that I'm not aware of, they don't like alloy tungsten in high ampere settings. The massive arc force is blowing the ceriated/thoriated particles out of the tungsten.

Try stepping up another tungsten size. While 1/8" may work well for 250A DC settings, using it on AC beats the sh** out of the T, so maybe try going a little bigger.

 

bump because I'm still having problems. I switched to 1/8 zirconiated and it's better, but it still does it. On high amps, it's like the machine is struggling. The arc pops and the machine kind of "shudders". it's hard to describe. Any ideas? I haven't tried pure tungsten but I don't see that being the problem. I'm running it off a 50A breaker with a pretty long power cord, but it never blows the breaker or anything. I'll probably call around to some distributors tomorrow

 

I use 1.5% Lanthanasted on AC. Never had a problem with it yet. Maintains a nice point.
Try 5/32nd :D lol

 

My machine (250 sync) seems to do the samething when on ac at around 250 amps. It seemed to start acting up when I had the pedal all the way down. What I did was turn my amprage up a bit more so I didn't have to floor the pedal. It seems to stop acting up if I use less then 95% pedal. Not sure if it is normal since the machine is a model year 2000 & has a **** load of use under its belt. By the way I am using green 1/8" tungsten.

 

Could be the wiring in the building is inadequite for the draw of the machine and the machine just can't pull the current it needs? I've had that happen before and it did kind of the same thing.

 

he isnt using an inverter machine.

however, I did weld some aluminum today and I just kept my pointed 2% in, and surprisingly it maintained a decent point despite being on a transformer machine. after about 30 min it started to deteriorate though

 

thats when the breaker would cut off.

 

Ground cable/clamp too small???

 

Has the machine ever been cleaned and the points for the high frequency been checked? Also try to adjust the level of the arc start.

 

I'm not using an Inverter either...
I wish I was though, lol

 

How does that weld, pretty nice? I may try that out on some scrap later on.



I use a 3/32" Thoriated tungsten for almost everything I do, just finished up some thick aluminium, running max 300ish amps with no problems. I would definitely recommend cleaning the machine if it's old and/or has been sitting around a dusty shop for a long time. I had to do some work on my welder and while trouble shooting I found a couple of important wires loose, and also found my intermittent loss of high frequency problem. Blow out all the dust you can and wipe it all down. Miller actually told me some guys would remove the boards from the older machines and hose them out

 

Not if the breaker is higher than the rated amperage of the wire