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Up Topic Welding Industry / Technical Discussions / Contamination with TIG Aluminum
- - By cbrxx Date 04-04-2003 23:48
Please look at the pictures in the link below. I'm welding 1/4" aluminum with 1/8" 2% Thoriated on AC. The welds seem to get contaminated with the 2% but look cleaner with the pure. Is the torch suppose to look like photo 1 or is something wrong.

[URL=]pics of welds[/URL]
Parent - - By DGXL (***) Date 04-05-2003 02:32
Try the high performance cups (nozzles). Had this same conversation last week with one client. You'll also notice these nozzles do not "stick" to the work while welding is in progress.

What is the composition of your shielding?

Parent - - By cbrxx Date 04-05-2003 02:40
100% argon, where can i find high performance nozzles?
Parent - - By DGXL (***) Date 04-05-2003 04:31
You will find the nozzles at just about any welding supply, there probably on the shelf next to the alumina nozzles your currently using. You will notice a difference. Compare photos with the one you posted after trying the HP nozzle.

You might inquire about a bottle of helium while your at it. It wil help flatten out those fillet welds and your production will increase as well.

If I were a computer geek, I would post photos of very clean and uniform welds using 2% Th tungsten. These welds were made on a variety of power sources. Don't make me repeat the car/driver bit (I'm sure everybody is tired of that one).

You guys need to be cautious about those weld terminations also. Without knowing what your application is, starts and stops are critical with aluminum. My nonferrous clients can attest to that fact.

What type of power supply is on the other end of that torch? Q maybe?
Parent - - By cbrxx Date 04-05-2003 15:11
I'm using a Miller Dynasty 300, AC 100hrtz 80%balance 25 cfm 280amps.
E-mail those photos to and I will post them, I would like to see how they look. I'm going to be welding aluminum displays and stands to support motorcycles and atvs. Thanks.
Parent - - By Lawrence (*****) Date 04-07-2003 15:36
Try adjusting your AC Frequency down to 40 Hz. At that amperage you should have no arc stability problems and the low frequency range available in the Dynasty is incorperated specifically for what you are doing. Also you might try lowering your AC Balance down to 70 or 75%. your photo #2 did not show real great etching.

Furthermore, your high amperage welding arc may be disturbing gas coverage, you could do some trials increasing your shielding gas flow in small incriments up to about 35 cfh, Fillits have a tendency to hold cover gas nicely so also check your torch angle and stand-off distance to be sure your form is good. (a poor torch angle will foul up all your good prep and parameters)

Your electrode appears to be in reasonable condition, Thorium is suitable as long as it does not split or grow little balls at the end (If you see this, know that you are transferring tungsten into the weld). Helium is also a great Idea when you are at the ragged edge of your powersource's output range. If you are equipped, a 50/50 mixture will do wonders.

I'm assuming that your welding 6061 Aluminum.. if not all bets are off :)
Let us know how you progress

Parent - By cbrxx Date 04-09-2003 02:30
Yes, its 6061 that i'm useing. Can you tell me the difference between 6061 and 5052, from what i have read they seem the same. I will lower my settings like you said and see if that helps. Do you know how I can check my gas for contamination?
Up Topic Welding Industry / Technical Discussions / Contamination with TIG Aluminum

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