Problem with Hobart Handler 140

[dirtguy34]

I have a Hobart Handler 140. When the unit was new I had no trouble welding aluminum...but now it beads up and will not weld. I have the polarity set at DCEP, 100% Argon gas, cranked to the max and it cannot run a puddle.

Is there anything in the unit that would break down and change the polarity?

Any ideas on this problem...it welds steel just fine with solid or flux core wire.

Thanks!

[DrIQ]

With aluminum there are Two things to consider.

1. Changes in ambient temperature and of the material.

2. The thickness of the material, aluminum normally requires 1 amp per .001 of thickness until you get into the 1/4" (.250) thickness range.

What thickness is the material you are trying to weld and is it the same thickness you welded before.

[Thomas Harris]

Just a guess here, but would dirt and wire residue in the liner cause this? Maybe grab a fresh liner and reserve that for aluminum only?

[dirtguy34]

Thanks for your replies...I'm taking these things into consideration and will definitely check out the liner!

[dirtguy34]

It turned out to be the liner was dirty (Bad from the flux core) and the O Rings were shot, and the main lead had gotten pulled out enough to see the first O ring. Thanks for all the help. Sorry it took so long to get back. Machines working good again!

thanks