Hello,

I have been TIG welding stainless long enough to get a hang of it but I
still consider myself a novice. I have bee quite successful last year making
this http://www.viatrack.ca/TURBOMAN/ and now I am attempting to finish it.

I encountered the following arc behavior problem. Occasionally as I strike
the entire tip would be enveloped in a blush glow. The arc would strike but
initially it would not be concentrated on the tip but it would seem to be
coming from the entire front end of the electrode. Eventually it would drop
down and emerge from the tip. This behavior started last year and was rare
but now it is getting worse. Yesterday after some successful welding it came
back wit the vengeance. I could not get the stable arc at all. It would
buzz and hiss loudly and really jump around. The electrode would glow
noticeably brighter and it would wear rapidly. There would be sooty deposits
in the strike area. At its worst the arc would emerge as a jet of blush
reddish plasma from the entire cup destroying the lens in the process. There
would be copper deposits on the sides of the tip and in one spot on the side
tungsten looked really shiny. I took the torch apart and reassembled it. The
problem went away but is showing signs of coming back. Is this a classic
symptom of something or a weird combination of novice errors?

The machine is Lincoln Squarewave 175
The torch is T-9
average current is 80 - 125 A DCEN
The electrode is 3/32 Th

Here are the pictures of what the damaged tip and lens look like.
http://www.viatrack.ca/Misc/TUNG_UN.jpg
http://www.viatrack.ca/Misc/LENS_UN.jpg



Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca

Boris Mohar wrote:

Hello,

I have been TIG welding stainless long enough to get a hang of it but I
still consider myself a novice. I have bee quite successful last year making
this http://www.viatrack.ca/TURBOMAN/ and now I am attempting to finish it.

I encountered the following arc behavior problem. Occasionally as I strike
the entire tip would be enveloped in a blush glow. The arc would strike but
initially it would not be concentrated on the tip but it would seem to be
coming from the entire front end of the electrode. Eventually it would drop
down and emerge from the tip. This behavior started last year and was rare
but now it is getting worse. Yesterday after some successful welding it came
back wit the vengeance. I could not get the stable arc at all. It would
buzz and hiss loudly and really jump around. The electrode would glow
noticeably brighter and it would wear rapidly. There would be sooty deposits
in the strike area. At its worst the arc would emerge as a jet of blush
reddish plasma from the entire cup destroying the lens in the process. There
would be copper deposits on the sides of the tip and in one spot on the side
tungsten looked really shiny. I took the torch apart and reassembled it. The
problem went away but is showing signs of coming back. Is this a classic
symptom of something or a weird combination of novice errors?

The machine is Lincoln Squarewave 175
The torch is T-9
average current is 80 - 125 A DCEN
The electrode is 3/32 Th

Here are the pictures of what the damaged tip and lens look like.
http://www.viatrack.ca/Misc/TUNG_UN.jpg
http://www.viatrack.ca/Misc/LENS_UN.jpg


Wow! I'm no expert, but I'm guessing something is contaminated. Or,
maybe --
do you have a water-cooled torch? Can you verify the cooling water is
flowing?
I'm wondering if the cooling passages have blocked up, and the electrode is
overheating. Then, chack your gas, and make sure there isn't a split in
the hose,
and the gas is really making it all the way to the torch. When I
activate the gas
valve in my welder, there is a puff of Argon from the pressure that has
built up
behind the solenoid valve. Do you get that puff?

I've certainly seen that business where the arc is coming from a wide
area of the
electrode. Generally it is a contaminated electrode, and regrinding
enough of it
to clean off the gunk would help. When I really globbed up an electrode in
the early days, I would have to grind the sides of it for a half inch or
so to remove
all the steel or whatever that was sticking to the sides. My technique
has improved
enough that I don't see this so much, anymore.

Are these pure Tungsten electrodes (EWP)? If so, you really have to try
almost
ANYTHING else. I think Zirconiated Tungsten is best for stainless.

The destruction of the gas lens is a new one on me. If your Argon is
flowing
without loss or restriction, the electrode is cooled and of the right
type, and
clean, and the cup is relatively clean, then I wonder about the gas. Is
this a
new tank? The tank could have been refilled with the wrong gas! Note that
the cups are expendable, and after they get dirty, they vaporize
deposited metal
back toward the electrode, and this can cause REAL problems. Sometimes,
you can scrape the whole mess off the cup, and it is just like new.
Other times,
it is burned into the surface, and the cup will crumble rather than come
clean.
I have seen this problem, where something was definitely wrong, I didn't
know
what, but saw a heavy, speckled deposit on the cup. When I cleaned it
off or
put on a new cup, everything went back to normal.

Jon

It sounds just like what happens when you forget to turn on the argon.
My guess is its a gas flow problem- either you forgot, or the valve was
sticky, or there was some teflon tape in the hose, or a kink, or
something along those lines.

On 1 May 2006 12:19:36 -0700, wrote:

It sounds just like what happens when you forget to turn on the argon.
My guess is its a gas flow problem- either you forgot, or the valve was
sticky, or there was some teflon tape in the hose, or a kink, or
something along those lines.

I have plenty of gas. I can feel it coming out and I have used half of the
bottle without this problem.

--

Boris Mohar

On Mon, 01 May 2006 13:46:41 -0500, Jon Elson
wrote:


The machine is Lincoln Squarewave 175
The torch is T-9
average current is 80 - 125 A DCEN
The electrode is 3/32 Th

Here are the pictures of what the damaged tip and lens look like.
http://www.viatrack.ca/Misc/TUNG_UN.jpg
http://www.viatrack.ca/Misc/LENS_UN.jpg


Redish jet of plasma? From the pictures and the text...my first guess
would be a bad tank of gas.

The electrodes reminds me of the time I stuck a tank of C-25 on my
tig, not knowing any better...cringe..blush....years ago..of course...

Gunner

"I think this is because of your belief in biological Marxism.
As a genetic communist you feel that noticing behavioural
patterns relating to race would cause a conflict with your belief
in biological Marxism." Big Pete, famous Usenet Racist

On Mon, 01 May 2006 21:05:25 GMT, Gunner wrote:

On Mon, 01 May 2006 13:46:41 -0500, Jon Elson
wrote:


The machine is Lincoln Squarewave 175
The torch is T-9
average current is 80 - 125 A DCEN
The electrode is 3/32 Th

Here are the pictures of what the damaged tip and lens look like.
http://www.viatrack.ca/Misc/TUNG_UN.jpg
http://www.viatrack.ca/Misc/LENS_UN.jpg


Redish jet of plasma? From the pictures and the text...my first guess
would be a bad tank of gas.

The electrodes reminds me of the time I stuck a tank of C-25 on my
tig, not knowing any better...cringe..blush....years ago..of course...


Cannot be. I used half of the bottle before it got this way.

--

Boris Mohar

On Mon, 01 May 2006 11:25:02 -0400, Boris Mohar
wrote:


Hello,

I have been TIG welding stainless long enough to get a hang of it but I
still consider myself a novice. I have bee quite successful last year making
this http://www.viatrack.ca/TURBOMAN/ and now I am attempting to finish it.

I encountered the following arc behavior problem. Occasionally as I strike
the entire tip would be enveloped in a blush glow. The arc would strike but
initially it would not be concentrated on the tip but it would seem to be
coming from the entire front end of the electrode. Eventually it would drop
down and emerge from the tip. This behavior started last year and was rare
but now it is getting worse. Yesterday after some successful welding it came
back wit the vengeance. I could not get the stable arc at all. It would
buzz and hiss loudly and really jump around. The electrode would glow
noticeably brighter and it would wear rapidly. There would be sooty deposits
in the strike area. At its worst the arc would emerge as a jet of blush
reddish plasma from the entire cup destroying the lens in the process. There
would be copper deposits on the sides of the tip and in one spot on the side
tungsten looked really shiny. I took the torch apart and reassembled it. The
problem went away but is showing signs of coming back. Is this a classic
symptom of something or a weird combination of novice errors?

The machine is Lincoln Squarewave 175
The torch is T-9
average current is 80 - 125 A DCEN
The electrode is 3/32 Th

Here are the pictures of what the damaged tip and lens look like.
http://www.viatrack.ca/Misc/TUNG_UN.jpg
http://www.viatrack.ca/Misc/LENS_UN.jpg



Regards,

Boris Mohar

Sounds to me like you're getting discharge in places other than from
tungsten tip to workpiece. That suggests a deposit of metal in the
various parts of your torch, cup, lens, etc.

You might try gritblasting those parts where a discharge could occur
from tungsten to metal deposit to workpiece.

You may need a new torch.

Don Foreman wrote:

Sounds to me like you're getting discharge in places other than from
tungsten tip to workpiece. That suggests a deposit of metal in the
various parts of your torch, cup, lens, etc.

You might try gritblasting those parts where a discharge could occur
from tungsten to metal deposit to workpiece.

You may need a new torch.

If there were conductive paths in the torch, he'd be getting zapped
by the HF. Hmm, that does give me a thought, that his HF is turned up
way too high. Some machines, like the bigger Lincolns, have so much
HF that you can actually weld thin materials without any real welding
current. The HF does tend to hop around a lot, too. But, the horrible
mess of his electrode and the total melting of the gas lens is not
something the HF system could do. Maybe if he was resting the torch or
gas lens cup against the workpiece, the welding current could jump to
the dirty cup and then to the work. That would almost certainly shatter
the cup within seconds, though. And, there'd be obvious arcing from
the cup to the work.

There is nothing in the torch handle that is grounded. There couldn't
be, or the HF would arc to it for sure.

Jon

On Tue, 02 May 2006 01:25:11 -0500, Don Foreman
wrote:

On Mon, 01 May 2006 11:25:02 -0400, Boris Mohar
wrote:


Hello,

I have been TIG welding stainless long enough to get a hang of it but I
still consider myself a novice. I have bee quite successful last year making
this http://www.viatrack.ca/TURBOMAN/ and now I am attempting to finish it.

I encountered the following arc behavior problem. Occasionally as I strike
the entire tip would be enveloped in a blush glow. The arc would strike but
initially it would not be concentrated on the tip but it would seem to be
coming from the entire front end of the electrode. Eventually it would drop
down and emerge from the tip. This behavior started last year and was rare
but now it is getting worse. Yesterday after some successful welding it came
back wit the vengeance. I could not get the stable arc at all. It would
buzz and hiss loudly and really jump around. The electrode would glow
noticeably brighter and it would wear rapidly. There would be sooty deposits
in the strike area. At its worst the arc would emerge as a jet of blush
reddish plasma from the entire cup destroying the lens in the process. There
would be copper deposits on the sides of the tip and in one spot on the side
tungsten looked really shiny. I took the torch apart and reassembled it. The
problem went away but is showing signs of coming back. Is this a classic
symptom of something or a weird combination of novice errors?

The machine is Lincoln Squarewave 175
The torch is T-9
average current is 80 - 125 A DCEN
The electrode is 3/32 Th

Here are the pictures of what the damaged tip and lens look like.
http://www.viatrack.ca/Misc/TUNG_UN.jpg
http://www.viatrack.ca/Misc/LENS_UN.jpg



Regards,

Boris Mohar

Sounds to me like you're getting discharge in places other than from
tungsten tip to workpiece. That suggests a deposit of metal in the
various parts of your torch, cup, lens, etc.

You might try gritblasting those parts where a discharge could occur
from tungsten to metal deposit to workpiece.

You may need a new torch.

I looked a the gas lens and indeed there were signs of brass melting around
the periphery. There also copper deposits in the tungsten in the region
where it emerges from the lens. I cleaned out all the threads on the
inside of the torch. When I was reassembling the torch I saw that there is a
spot for the wrench on the lens and I have been installing it only finger
tight. So now I made sure the lens is in snug. The wild arc behavior is
gone. Thanks for all the help.

--

Boris Mohar

On Tue, 02 May 2006 01:46:34 -0500, Jon Elson
wrote:

Don Foreman wrote:

Sounds to me like you're getting discharge in places other than from
tungsten tip to workpiece. That suggests a deposit of metal in the
various parts of your torch, cup, lens, etc.

You might try gritblasting those parts where a discharge could occur
from tungsten to metal deposit to workpiece.

You may need a new torch.

If there were conductive paths in the torch, he'd be getting zapped
by the HF.

Not if the conductive material were only in and around the cup, not
extending anywhere near where the user holds the torch. This seems
to be the most likely region of contamination.