Tig Beginner : setting up Powertig 200dx-d for aluminum Tig

[projectvr6]

-Purchased my PowerTig 200-DX-d about a year ago and have used it for a few projects using the SMAW function. Very happy with the machine.

-This weekend I finally got around to getting my Argon bottle and tried testing it out on TIG AC, as I would like to practice tig welding aluminum.
-I wanted to test the machine on a piece of clean 3/8 aluminum plate(all i had available at the time), set the machine around 160 amps.

Welder settings:plugged into 240V

Pulse:off
Tried using 2T and 4T
AC
HF start
No pre or post flow
Frequency:20
Balance:30

Torch was plugged in negative.
Argon flow I varied from 10 to 20L(I forgot the regs that are supplied are not gauged in CFH)

So can any of you experienced guys tell me where i may have gone horrible wrong>?, because as soon as i hit the switch on the torch, the arc seemed extremely violent and rough...and almost seemed to be gouging the aluminum at times...leaving black marks around the beads.
I did not do much more experimenting in case I had a chance of doing any damage due to improper settings so any advice to lead me in the right direction would be great!

Thanks

[Rambozo]

You will need some pre and post flow to protect the tungsten. .5 seconds for pre and enough post that the tungsten is no longer red before it stops. About 10 seconds per hundred amps is a good starting point. A good frequency to start at is 100-120. Balance at 30 is fine. The arc will be a lot different than DC, so don't expect something as smooth and quiet. Be sure you have good argon flow. With a #6 - #8 cup, around 15-20 CFH (7-10 lpm) is a good start. Use a foot pedal if you have one so you can start and end at lower current.

[Blaster]

enough post that the tungsten is no longer red before it stops. About 10 seconds per hundred amps is a good starting point.

Argon costs were Killing me at high amperage and here's what I started to do (not sure if this is a good idea, tell me what you think, I respect your opinion...)

I cut flow back to about 8secs and once finishing a weld I would wait about 1/2 that and touch the tungsten (it was still "reddish" but not bright) to the parent metal, a couple of inches way from the weld site. It never felt doughy or stuck in and way but it did make a dramatic difference in cooling, you can just watch the electrode go immediately "dark". I started doing this when using a long Pyrex cup, in corners, with so much more stick-out at 250A on 6061.

It works, I'm sure it saved me a Ton of Argon, and I don't think I see the effects of contamination, but I'm not sure I should be doing it!

[m j mauer]

Welcome to the forum projectvr6.
I think you would be ahead of the game if you started with steel.

[Rambozo]

Argon costs were Killing me at high amperage and here's what I started to do (not sure if this is a good idea, tell me what you think, I respect your opinion...)

I cut flow back to about 8secs and once finishing a weld I would wait about 1/2 that and touch the tungsten (it was still "reddish" but not bright) to the parent metal, a couple of inches way from the weld site. It never felt doughy or stuck in and way but it did make a dramatic difference in cooling, you can just watch the electrode go immediately "dark". I started doing this when using a long Pyrex cup, in corners, with so much more stick-out at 250A on 6061.

It works, I'm sure it saved me a Ton of Argon, and I don't think I see the effects of contamination, but I'm not sure I should be doing it!

It's probably not ideal, but it's not like you are doing X-ray welding in a nuclear plant, either. As long as your next start doesn't show any characteristics of contamination, such as a colored tint to the light, you should be OK. Unless you are doing nothing but tacks, I can't see how the extra seconds will save you that much gas. Plan your welds and get your setups better and you will see major reductions in both time and argon use. Also get the largest bottle you can handle for the lowest gas cost. I saw your homemade gas saver setup. That is much like a few commercial products. If you want, read up on "choked flow" to understand why most systems use a restriction with a single stage regulator. There are a few slightly different requirements between MIG and TIG, so some things only apply to one or the other. Most MIGs don't have preflow so they benefit from a small extra blast at the start to purge.

[Blaster]

My welds are only about an inch long ea. If I waited to see a cool tungsten I would have to triple the post when I have the 1/8" electrode 2" long at 250A. My recent project, building Aluminum Fireworks Pods, I've gone through 6 - 300ltr tanks! In retrospect, I should have Migged them, the Argon savings would have almost paid for the spool gun...

I don't think it was Me with the "homemade gas saver", but I Do use a Gas Lens system.

[Rambozo]

I don't think it was Me with the "homemade gas saver", but I Do use a Gas Lens system.

Sorry, that was Richard. Are you using a water cooled torch? They really pull the heat out of the tungsten, fast. For 1" long welds, if you can't group a bunch of them together to weld in one go, it will be hard on the gas. You just need to factor that in when you bid the job. MIG will almost always beat TIG for speed and cost. If you can use it, you should.

[Blaster]

Oh this is Water Cooled, and as I said, only became an issue since I was using the Long Cup with its Long Electrode exposed.

The welds are spaced pretty far apart, I can "rush" from one site to another but, it's not all that a comfortable thing to do. I also like giving the Duty Cycle (30% on my PP256) a chance...

So, I'm not so much a Weldor doing a Fireworks Job, as a Fireworks Guy who's Welding Since my State has recently approved these Finale Pods (2.5-6") to be constructed of Alum instead of Wood, this has been my Winter Project. It's all for Me - just didn't anticipate almost $500 in Gas

I don't own a Spool Gun but, maybe would have had I known. At least I'm sure of all my welds by Tigging (I've seen too many Mig welds that can casually "look" better than they actually Are)

[Glassbeaver]

To the op, what you're describing sounds like a gas issue. Frequency is way off to(120ish). Welding outside?


Everlast 200DX (Dual Voltage)
Northern Tool Dry Cut Saw

[projectvr6]

Thanks everyone for the input, I will make some changes once i get the chance to get back to it.

[projectvr6]

To the op, what you're describing sounds like a gas issue. Frequency is way off to(120ish). Welding outside?


Everlast 200DX (Dual Voltage)
Northern Tool Dry Cut Saw

Thanks, i will definitely make the adjustments and give it a try.
I was welding in a shop, but I did think my gas setup was way off, when realizing afterwards the reg is not gauged in cfh.
Will get some time tomorrow to check it out and will hopefully make some improvements.

[joshuab]

If you have an LPM gauge, the numbers are approximately half of what you would set in CFH.