Sputtering in AC mode

[Chevelle69]

Well tried machine again today. Lots better. What seemed to help the most was a shorter taper on my tungsten. Popping has all but stopped. Still at pops at very low amps but I can manage now. Thanks everyone for the tips

[Chevelle69]

If you have been following my sputtering torch thread here is the end of it.
Took out the auto antifreeze and put in distiller water . What do you know my sputter on AC is gone and the torch starts smoother. This was driving me crazy. I can now ramp down to 5amps and still have a steady non sputtering arc. I read somewhere that this could cause hf problems. Made sense that AC welding is basically hf welding. And dc is straight. Hf start on dc have cleaned up tremendously as well.
Last edited by Chevelle69; Today at 08:47 PM.

[labmaster02]

I didn't realize you had a water cooled torch. This is strange that the coolant type would affect the arc. Glad to hear you got it going.

I was watching some old Everlast videos on the 2013 255ext as it was being released and they were demonstrating low amp welding aluminum. They started on 5 amps and it it was extremely smooth and repeated several times in a row. They also lite up on the bottom edge of a soda can and it puddled beautifully. I set my machine on the same settings and all it would do was flare up and vaporizer the can. They also set the balance at 35% with 1/16 tungsten at 35 amps. All mine does it ball up and melt the tip. I have to lower the balance to 20 before the tip stays intact. I've never been able to get mine to start that low and have the arc come off of the tip.

[Blaster]

Why would you even use a W/C torch for such low amperage?

I'd think you'd be happier in all respects with a smaller, lighter, more "agile" A/C torch for delicate work...

[Chevelle69]

Supposedly the coolant was conductive this was affecting my hf start as well as AC welding at low amps. That's why the arc was jumping back up inside the cup at low amps. I guess it was taking the least path of resistance to the coolant inside the copper head of the torch. Didn't realize it was affecting my hf on both AC and dc until I swapped to water and noticed how smooth it is now. I don't understand it fully but sometimes a fix is a fix.

[cadguy]

Supposedly the coolant was conductive this was affecting my hf start as well as AC welding at low amps. That's why the arc was jumping back up inside the cup at low amps. I guess it was taking the least path of resistance to the coolant inside the copper head of the torch. Didn't realize it was affecting my hf on both AC and dc until I swapped to water and noticed how smooth it is now. I don't understand it fully but sometimes a fix is a fix.

mine does the same thing with a dry torch (gas cooled)

[TD2593]

If you have been following my sputtering torch thread here is the end of it.
Took out the auto antifreeze and put in distiller water . What do you know my sputter on AC is gone and the torch starts smoother. This was driving me crazy. I can now ramp down to 5amps and still have a steady non sputtering arc. I read somewhere that this could cause hf problems. Made sense that AC welding is basically hf welding. And dc is straight. Hf start on dc have cleaned up tremendously as well.
Last edited by Chevelle69; Today at 08:47 PM.

I have a air cooled torch and have this problem at lower amps, I pump the amps up and it goes away. I am using a 3/32 lanthinated. Ill try some of the things that have been mentioned, the machine has done this from day one at low amps, the arc will, for lack of a better term, start and stop at low amps, no arc wander. Could this be a HF issue ? I have had the AC balance all over the place with the same results.

[performance]

For arc stability at low amps, you have to use a small diameter tungsten. .040 or 1/16"

[TD2593]

For arc stability at low amps, you have to use a small diameter tungsten. .040 or 1/16"

I dont have this problem when I use my buddy's Dynasty 200 with the same 3/32 tungsten. Is it something Im missing on set up ?

[performance]

What Miller doesn't tell you is that they have a built in "surge" to establish an arc that you will not see. When we went through the whole 250EXT ordeal a couple years ago, this is one thing we found out but you will likely not see it reflected. Lincoln as well. We've worked hard to eliminate the surge on our new models, but the old 250EXT had a surge that was a little hotter and longer than it should have been and it reflected in the display.

The issue can also be a result of a poor/indirect work clamp connection.

FWIW, we've got things we can do that the Dynasty cannot do at all or do as well. I wouldn't say capabilities are exactly equal and it's not fair to assume everything will work exactly the same on either unit. They are not "clones" of each other. Try the smaller tungsten and try to check all your connections and make your work clamp connection directly to the piece you are welding, grind a spot if necessary.

[rick9345]

Personally I like my 2013 250EX and its no amperage surge start, easily controlled with a well tuned pedal. the only thing I miss from my older Miller transformers is the ability to have constant HF. In ultra low amperage use in AC/DC I feel I had better arc control with out the need to change to the smaller tungsten,(just lazy I guess). The smaller tungsten is the better solution.