HAWK, ac steel ?

[Blown S-10]

you mentioned you like to 99%en ac steel. why do you do this ? sounds interesting.

[HAWK]

Blown S-10,

I do up to 1" mild steel with a 50/50 helium/argon mix on AC running a 95%-99% EN balance. This is basically a DC weld with such a high EN balance and gives some added arc cleaning action. It also allows for arc frequency adjustment. It seems to improve electrode life as well. It is a process that works well for some of my client's projects.

I have seen a very small amount of published literature of for AC TIG on steel with the advanced squarewave arc machines such as the Dynasty up to 1/8" with 100% argon. The process I am using is not documented or used outside of my shop as far as I know. I am using a D300DX so the 1" is not a problem. I am sure you can get there with many passes using the D200DX as well on 240 VAC.

Let me know what you think.

[spoolup89]

Hawk I Have A ???

I really like my 300dx what little time I have had on it. From what I recall you own a 300dx also. If not they say thats the 2nd thing to go. What I am wondering about is the welding sound on ac? I know it has a buzz to it but I get a like popping or cracking sound also. This is not a constant sound but quit frequent while welding on ac. Have you noticed this or is this trouble. I have nothing to compare it to except my old sync.
Thanks gregg

[Blown S-10]

sounds interesting. i'll give it a little test try one of these days. thanx

[HAWK]

Spoolup89,

The buzz is normal. I have not noticed the cracking sound. What tungsten alloy are you using and how are you preparing it? It almost sounds like your tungsten is contaminated.

Now that I think about it I have heard a popping sound on dirty aluminum. For example I was in a hurry and just hit the surface with a contaminated Scotch Brite pad or did not wipe with acetone after using Scotch Brite. Usually the popping is accompanied by little sparks coming off the aluminum and hitting the tungsten.

If this is happening your tungsten is definitley contaminated. I clean my base material as well as my filler rods with Scotch Brite and then wipe with acetone. When I do it right I do not get a popping sound.

Since you have been tigging a while I doubt you are hitting the tungsten with the filler. However, that can cause a cracking sound on the Dynasty.

Your machine could have a problem, but I am trying to eliminate welding procedure problems first.

Let me know if any of this helps or if I am off base. Sometimes it is hard to diagnose without being there.

[Blown S-10]

i have heard a cracking sound also. best i can figure, its not clean enough aluminum.

[spoolup89]

Sound

Well I didnt weld any alum yeat. I spent the weekend welding steel for my cart. I will try to really clean some alum and see if that works.

Hawk, I am using lanthanated ground to a point with a flat end.This is on a grinder I use for tungsten only. I thing it was a cleaning thing or lack of. Will let you know soon.

Thanks gregg

[HAWK]

Spoolup89,

I have a feeling that is all it is. I was testing a used torch last evening before shipping it out and grabbed a couple pieces of 6061T-651 in 3/8x2x6 inch sections. I tacked a T joint and ran a couple fillets with base metal cooling time in between. I did not clean either piece and got an orange(ish) glow with once the Al got heated all through and lots of popping and sparks. A later examination revealed lots of oxide inclusions.

[ASKANDY]

That extra crackling is normal in an inverter and gets worse if you have the balance up too high or your arc length too low. Nothing to worry about though.

a

[HAWK]

A-,

Been running 110HZ, 72% EN, 200 amps on 3/8" fillets, gone back to 100% argon, good clean aluminum and no crackle. Thanks for the info. It will make things easier to get back in tune.