Tigging Stainless Steel

[borris]

I'm fairly good at welding alloy steel and aluminum but have just started welding SS.I'm getting a grayish deposit on the weld.What am I doing wrong?

[Admin]

Are you dripping bong water on it?

[borris]

LOL!!! Like ,that'd be black or brown----maaaan!

[Entropy]

Are you running a gas lenz?
Are you running enough pre and more importantly post flow? Don't pull the torch till the post flow stops even back up the weld a bit and wash it...
Are you overheating it.
Have you contaminated the weld or T some how?
Are you welding tube or sheet?
Do you have a tight fitting joint (no gaps) or is it a bit sloppy?  Air will leak through the gaps and disturb the shield...
Are you holding your tongue on your right eye tooth while humming ether Jethro Tull or Mr. Cash?

Could be any of those or...

[fabr]

Are you running a gas lenz?
Are you running enough pre and more importantly post flow? Don't pull the torch till the post flow stops even back up the weld a bit and wash it...
Are you overheating it.
Have you contaminated the weld or T some how?
Are you welding tube or sheet?
Do you have a tight fitting joint (no gaps) or is it a bit sloppy?  Air will leak through the gaps and disturb the shield...
Are you holding your tongue on your right eye tooth while humming ether Jethro Tull or Mr. Cash?

Could be any of those or...

Dammit entropy! leave it to you to ask pertinent questions! :)LOL!!!       First for the readers I'd like you to explain what a gas lenz is compared to a regular cup. But yes I am.
  Yes I think I'm doing an adequate job of the post flow.I let the weld cool till it isn't red any more.Do I need to do it longer than that?
  I have preflow for about 1-2 seconds before striking the arc.Enough?
  Metal is squeaky clean .
 
  Doing a header so it's part tube and I guess you'd say part sheet.

  Very tight no gaps fit up.

  Oh ,hell!!! There's the problem I was humming along to Aerosmith!
 

[Entropy]

Dammit entropy! leave it to you to ask pertinent questions! :)LOL!!!       First for the readers I'd like you to explain what a gas lenz is compared to a regular cup. But yes I am.
  Yes I think I'm doing an adequate job of the post flow.I let the weld cool till it isn't red any more.Do I need to do it longer than that?
  I have preflow for about 1-2 seconds before striking the arc.Enough?
  Metal is squeaky clean .
 
  Doing a header so it's part tube and I guess you'd say part sheet.

  Very tight no gaps fit up.

  Oh ,hell!!! There's the problem I was humming along to Aerosmith!
 

Aerosmith can be disruptive, but you can sometimes get away with "TIG this way".
Couple other things you need still air in the shop when TIG'n Stainless (any) tube and you need to have a relatively High Volume gas flow at a lower pressure.  If the gas speed is to high it will flow around the tube and pull in O2...
Try dropping the pressure by 1/2 to 1/3 and see if that helps.

[fabr]

Aha!!! Hadn't thought about the flow around the tube. :P DUh ,same as with doing a roll cage ,huh?.

[Entropy]

Yup.

[borris]

For our readers would you point out the differences between a gas lens and a regular cup and what it does for the gas flow?

[Whiplash]

Yeah I am unsure of the difference as well!

[Entropy]

For our readers would you point out the differences between a gas lens and a regular cup and what it does for the gas flow?

No!

Oh ok...

The gas lenz is basically a screen that is installed between the torch body and the Cup, or that pink thingy  that is ceramic that screws on and hides the Tungsten...
Is that enough?
Crap! More Eh?
Alright. So what the screen does is it defuses the gas flow through and subsequently out of the cup.
Instead of a few jets of Argon creating thick and thin coverage, you get a cylinder of argon that surrounds completely the Arc...
So there is Even gas flow, rather then the uneven flow of the standard set up.
The real question is WTF??? does it do in this case...
OK so pay attention here!
When you are welding flat stock the gas comes out of the standard set-up and it flows all over the work and unless it is blown off it covers the weld zone.
Round work however lets the gas flow around the surface, when that happens the higher velocity streams of argon will actually pull the room air in and you will get O2 in to the weld zone, and this will cause all kinds of bad Juju! Like Gray welds that should be gold...
Further on round work you may need to reduce the pressure of the shield (always can with a lenz) to reduce the "wash" effect.

Howz that?

[borris]

Thanks Entropy! Answers like that are always better coming from a pro like yourself instead of a hack like myself! We appreciate your help!

[Entropy]

No problem...
I think

[VLADD]

That was an awesome lesson Entropy...And right on the money

[borris]

Aerosmith can be disruptive, but you can sometimes get away with "TIG this way".
Couple other things you need still air in the shop when TIG'n Stainless (any) tube and you need to have a relatively High Volume gas flow at a lower pressure.  If the gas speed is to high it will flow around the tube and pull in O2...
Try dropping the pressure by 1/2 to 1/3 and see if that helps.

Hehehe,I'll have to try and find that cut!LOL!!!