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Up Topic Welding Industry / General Welding Discussion / Aluminum MIG Problems
- - By TomPace Date 09-13-2001 00:52
I am new to aluminum wire welding. I am using a Miller CV power source with a Spoolmatic 30A. I have switched the polarity and still have problems with black welds and little to no penetration. What am i doing wrong.?
Parent - - By bhiltz (**) Date 09-13-2001 09:55
you should be on reverse polarity & give a little more information
Parent - - By TomPace Date 09-13-2001 10:56
In reply, as stated, I reversed the polarity per Miller's suggestion. I am using 100% Argon. The machine I am using is a Miller Regency 200 CV with a Spoolmatic 30A wire feed. The weld bead is very poor and penetration is neel. There is little noticeable difference when I have switched polarity.


T Pace
Parent - By dasimonds (**) Date 09-13-2001 11:59
Are you using a drag angle on your gun? That would give you a black, lumped up weld. Aluminum welds better with a push angle.

Also, Helium/argon shielding gas (50/50?).
Parent - - By RonG (****) Date 09-13-2001 11:44
Have you tried PreHeat? Aluminum is real touchy about preheat.

It is a very good Heat Sink and will rob the heat from your Arc.

Many years ago we would lite the Oxy-Acet torch turn off the Oxy and cover the work area with the black soot then tune the torch back to a neutral flame and preheat until the soot burned off then it was ready to weld, but now days you can just go pick a 400 deg F temp stick or use a Pyrometer.

As for the Black have you cleaned the work? Another thing Aluminum is touchy about. Some Aluminum products have a coating to prevent oxidation, and then again some are not pure Aluminum.

If you look back thru some earlier posts on this Forum you find other discussions on Aluminum with lots of useful information.

Parent - By RONALD HANCOCK (*) Date 09-13-2001 14:31
Parent - - By Lawrence (*****) Date 09-13-2001 20:17
HI Tom,

Try this link

This one is so good I printed off some of the pages and laminated them so that they could be posted next to the power sources in my classroom. It addresses questions for both GTA and Squirtwelders

By the way, much of the GTA data presented on the Miller Website was also posted in the "Welding Journal" in May 2000, This is without a doubt the *BEST*, most trustworthy and surprisingly enough, free information available related to GTAW power sources, especially for those with an interest in Hybrid or Asymmetric power.

Let us know how it goes


Parent - By TomPace Date 09-15-2001 02:23

I have good news to report. I changed leads and cleaned the nozzle.
I basically was not familiar with welding aluminum using the MIG process.
Adjusting the wire speed helped the best.

Thank you all for your input with my problem.


Tom Pace
Up Topic Welding Industry / General Welding Discussion / Aluminum MIG Problems

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