A couple of TIG questions, if that's ok...

First, let me say hello since I am new to this group.

I'm new to welding and I have a TIG machine. Things seem to be going ok except I get these bubbles in the weld. I don't know if I have the gas flow too high and it is making the weld pool splash or something in the metal.

Here are a couple of pics,

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My other question is, how do you know how far the weld is penetrating?

If anyone could help me that would be great.

Thanks, Raul

Reply to
raul
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looks like impurities. was that metal clean before you welded it? what type of metal? what gas and flow rate? what tungsten, size, and weld current? DCSP or DCRP?

Reply to
Kryptoknight

It's just scrap piping from a yard next to my house. I just brush it to clean it. It's steel as far as I know. The grade I have no idea.

The gas is argon. Flow rate is 15 cfh The rod is red, a little less than 2mil. DCSP I guess. Here's my machine, it's the 201A

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Thanks, Raul

Reply to
raul

Your gas and flow rate is good, and you should be DCSP. Looks like carbon steel pipe, if there is any dirt, oil, grease,...etc on the pipe you'll get these results, or if your welding outside and there is a breeze that would interfere with the gas flow.

Richard

Reply to
Art Van Dalay

I just switched the leads to change the polarity and the machine worked fine. Actually, the arc seemed more stable but it balled up the tungsten quite quickly. The power was on the lowest setting.

I wonder why?

Thanks, Raul

Reply to
raul

Is that paint or rust on the pipe? Either will cause the porosity/slag inclusions I see. Did you buff the weld area before welding? A small bit of oil,paint/rust/dirt/crud can cause a big bubble.

It's gotta be clean. Other than that, the welds look pretty good for a beginner.

You have to cut the weld transversely to examine the penetration, or look on the inside of the pipe if you can see that far. Easier to cut the pipe, then you can see the entire weld.

HTH

Steve

Reply to
Steve B

when you reversed the leads the majority of the heat transferred to the torch instead of the majority going to the peice being welded.

most of the time you should use the tig torch plugged into the negative

- and the ground clamp on the +

there is a difference on which "side" of the arc gets more heat and without going into a pile of electronics and molecular theory it cant be explained. ANd it might set off all sorts of discussions here about nitpicking over why it does that when i hope i can just say "thats the way it is" and leave it at that

Reply to
Brent Philion

"Brent Philion" wrote

ANd it might set off all sorts of discussions here about

"Reality is nature's way of keeping things straight."

Steve

Reply to
Steve B

My guess is that the pipe is galvanized and that you don't have every bit of the zinc off. Try grinding the surface or try some other metal.

Dan

Reply to
dcaster

"The rod is red, a little less than 2mil." Most gas and TIG rod is coated with copper to limit rusting so we'd expect it to be "red."

However, this still begs the question, What type of rod are you using? If it's RG-45--an oxy-fuel rod--you _will_ get porosity without question.

A person _must_ use a rod designed for TIG welding which is metalergically designed for a TIG arc enviornment. The commone ones for mild steet have designations such as ER-70S-2 or ER-70S-6. Either will do for most applications but the ER-70S-6 is better for not-so-clean metal (i.e., better at preventing porosity from impurities).

Ciao, David Todtman

Reply to
David Todtman

The filler rod must be TIG intended. If you use regular gas welding rod you tend to get bubbling and porosity at the end of your beads. The main weld seem fine on the pipe. It looks like your problems are with your starts and stops? Don't lift the cup away when you are finished. Hesitate and fill your craters at the end of your weld. If you are running with a pedal then you can taper your heat down as you fill the crater and still be shielding the whole are until it is cool. If your bead sits high that is an indication that you are lacking penetration. The contour of your beads looks good on both sides of the mess you centred the picture on. Randy

The gas is argon. Flow rate is 15 cfh The rod is red, a little less than 2mil. DCSP I guess. Here's my machine, it's the 201A

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Thanks, Raul

Reply to
R. Zimmerman

I looked at the pictures. One bead looks like your making a lake on the metal.

The other bead, you tightened up the beads, much improved...you are getting the hang of it...

xman

Reply to
xmradio

Steve- It's just rust on the pipe, I don't do a good job cleaning it because it's scrap anyway.

David- The end of the TIG rod is painted red, so I'm guessing it's EWth-2 (That's what my book says). I'm not using any filler rod.

R. Zimmerman- Unfortunately my machine only has a power control on the machine, so I can't taper off so to speak. But it was only $400. so I can't complain.

Thanks fo all your help. Raul

Reply to
raul

What's changed to make the difference ?

Reply to
Martin Evans

Did you bother to read the comments I made about rust, paint, oil, and dirt getting into welds and causing porosity?

I didn't think so.

Steve

Reply to
Steve B

I think the convention for the word "rod" is that it refers to a consumable, especially in gas or tig applications. The convention for the tungsten is "tungsten" or tungsten electrode.

I am not clear from you post but it may be that you are not cleaning all the rust off the weld area and HAZ (heat affected zone). If you leave rust, especiall in or very near the weld zone you mess up the weld. TIG welding requires very, very clean metal.

It's all learning.

Best, David

Reply to
David Todtman

i think Oxy rod has deoxidizing additives if memory serves

Reply to
Brent Philion

The addition of a filler rod is not only to fill up a gap when TIG welding. Silicon and sometimes aluminum are added to the filler wire/rod. These elements grab the unwanted oxygen. The glass, ( silicon oxide ) sitting on top of the cooled weld pool is evidence of this action. TIG filler rods have more deoxidizers in them than regular Oxy-acetylene welding rods. Generally welding steel without filler rod risks bubbling and porosity especially at the end of the weld bead. Randy

i think Oxy rod has deoxidizing additives if memory serves

Reply to
R. Zimmerman

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