[gnabgib]

I'm using a Kemppi MasterTig and welding 80mm diameter X 6mm steel pipe. Tungsten is 2.4 Lanthanated, 110 amps approx. Argon is around 7 to 9 Lpm and filler wire is ER 70S-4. Ok, that should all be good but I'm getting a wrinkled effect on the surface of the weld. According to what I've read, it's contamination. If this is so...How?

[weldin mike 27]

Hi there,

Try one of Jodys' tricks, an argon dam. Secure a couple of layers of aluminium foil to the underside of the pipe and shape it so it forms a bath shape around the weld area. This should stop the argon flowing away too quick.

Mick

[Otto Nobedder]

Are you walking the cup?

If so, the weld is still too hot when the cup comes in contact with it behind the weld. (I've had this happen.) Try a larger cup and, if needed, a bit more gas. You may need to increase travel speed, but a larger cup will pretty much do that for you. I like at least a 1" or 25mm cup for walking pipe.

If you're free-handing, you may be allowing the weld zone to overheat, so it's back to travel speed.

If neither of these apply, I'm at a loss with the information you provided.

Steve

[gnabgib]

Hi Steve,
Walking the cup is beyond me. I had previously tried a 10 cup and 10lpm but no change. Someone in another post here suggested that it's possible for an Argon bottle to be contaminated possibly by remnants of Argon/Co2 mix. One thing I've noticed is that the arc produced is fierce, like it's spraying off the end of the electrode and I've also been getting a few spits from the pool when starting. Gas refilled last week.
The Kemppi has a semi-auto set-up and the display indicates that a 1.6 electrode can be used up to 110 amps? I'm using 2.4. Had had no problems previously when using these parameters on a different make, but 3 phase power supply machine, whereas the Kemppi is single phase. I am slow at this so you might be correct about the heat aspect. I could try a 1.6 electrode but doesn't make any sense for 6mm material.

Jeff

[Otto Nobedder]

Jeff,

I'd be concerned about that description of a "harsh" arc, especially coupled with "spits from the puddle". First, rule out gas-flow problems at the torch. I (and someone here very recently) have had obstruction problems with gas flow at the torch (mine with a gas lens, his with a plain collet-body). Leaks between flowmeter and torch are another possibility.

If that's all good,

Your machine may have a weak or failing diode, introducing an AC component on top of your DC current, which will wreak havoc. Actually, any number of internal problems could cause this.

If you have a friend with a known-good machine, ask for a little bit of "arc time" just to prove to yourself that it isn't you (and I don't think it is), then consider having the machine serviced.

Steve

[gnabgib]

Steve,
Thanks for your detailed replies. I don't like the sound of electronic component problems, after only a handful of paying jobs with it. How about a bent and twisted collet? Hmm, change that and see!

Jeff

[gnabgib]

Hi there,

Try one of Jodys' tricks, an argon dam. Secure a couple of layers of aluminium foil to the underside of the pipe and shape it so it forms a bath shape around the weld area. This should stop the argon flowing away too quick.

Mick

Thanks for the suggestion Mick but that's really only feasible for those specialized one-off jobs or where it is a known, gas escaping problem. Doing the pressure pipe requires multiple passes, 4 in 2G position, and it's the appearance of the capping that is unsettling me ie. just shouldn't look like it is.

Jeff

[Otto Nobedder]

Jeff,

The more I think about what you wrote, the more I suspect a gas flow problem of some sort. If you can trigger the gas with the torch head disassambled, you should hear a very strong hiss of gas. If not, you may have an obstruction between the bottle and the torch.

If you have strong flow at the torch, a new collet, as you said, may solve the problem.

Good luck,

Steve

[winky]

Generally if there is a contaminated argon tank it will be contaminated with moisture … this will cause a beard on your arc … easy to identify … I think Steve (Otto Nobedder) has a good point … make sure you don’t have an argon obstruction … another sign of insufficient shielding gas flow is porosity … if it looks like your beads have little holes in them that is porosity. Also make sure you aren't tilting your torch too much ... this too can cause inadequacy of shielding.

[gnabgib]

How about this? I'm pretty sure there is nothing wrong with the gas flow or the torch, quality of the gas might be another matter, and the books etc. say it's contamination, so I had another look at the filler wire spec sheets. I'm using the ER70S-4, but Comweld states that "Supersteel" ER70S-2 is a triple deoxidized wire which should be better at dealing with any contamination that would occur on multiple passes.

Jeff

[Otto Nobedder]

Contamination sounds like a solid yroeht, gnabgib ? ...er... theory.

Do you have a second bottle you can swap to to test this?

Steve

[RedIron881]

Hey Jeff,

Think you could post some photos of this problem you're having? Pictures speak a thousand words, ha ha!

[gnabgib]

Contamination sounds like a solid yroeht, gnabgib ? ...er... theory.

Do you have a second bottle you can swap to to test this?

Steve

Ok, Otto...Or is that, ottO? Don't have a second bottle but I might just have to take the machine to someone who has. Until then I'll bag some of the other wire. Jeff

[gnabgib]

Hey Jeff,

Think you could post some photos of this problem you're having? Pictures speak a thousand words, ha ha!

I tried to do a photo to include here but the result wasn't that good. The Miller site has a very good example of what I experienced and it looks like a spiders web of wrinkles.

[gnabgib]

Contamination sounds like a solid yroeht, gnabgib ? ...er... theory.

Do you have a second bottle you can swap to to test this?

Steve

Well, surprise, surprise!! The supplier has now admitted that I had been given an Argon/Co2 mix in an Argon labeled bottle. I believe that the stress this caused when I needed additional welding time just before a #7 pressure ticket test, cost me a 100% pass. Passed the theory and the 5G, but failed the 2G. Fortunately I can redo just that.

PS. Supplier said I was mistakenly supplied a 'mix' and I assumed they meant Argon/Co2 but someone I know pointed out that it could have been Argon/Helium. If so it might explain the odd arc I was getting.

[weldin mike 27]

Hey there,

I wish i knew about Jodys' vids when I did my number 7. Most of the time I was flying blind. I told a recent group about them and they loaded them up on the teachers laptop in the class room.

Mick

[gnabgib]

Hi Mick,
Yes, very good info in all those. Makes it look easy....Ha! If only.

Cheers, Jeff

Hey there,

I wish i knew about Jodys' vids when I did my number 7. Most of the time I was flying blind. I told a recent group about them and they loaded them up on the teachers laptop in the class room.

Mick

[weldin mike 27]

Hey,

You're right there. What that man can do with a tig boggles my mind. And then says, "oh thats not as good as it could be cause the cameras in the way." Lol. Seriously though, Thanks Jody, you're awesome.

Mick.

[Otto Nobedder]

gnabgib,

I'm glad you've solved this one. Every time a problem like that gets solved, we all learn something; What to look at when we encounter a similar problem.

Here's a recent one from my own experience.

I had to weld a vacuum-tight doubler over a severe rust location (rust and scale more than 50% through the vacuum vessel). We always make a repair doubler like this "live" by drilling a hole through the questionable area. As the parent metal was 3/8" carbon steel, the doubler was the same. I dug out my 1/8" gas lens, collet, and tungsten, and went to work. Almost immediately I was getting porosity, and "sparkles" from the weld, so I went back to my stash and grabbed a "fresh" tungsten with the red band still on it. Same result. I switched argon bottles, same result. Tried brand-new tungsten from a sealed container, and Viola', welded like it should. I don't know how my tungsten got contaminated, or with what, but I no longer store them in anything but a sealed stainless-steel container.

Steve

[gnabgib]

Hi Steve,
Thank you and to others for the supporting comments. So, if Argon/Helium, do you have an ideas or experience of that if it's used on low carbon steel? Greater heat input yes.
As for your experience with Tungsten electrodes, if metal dust ends up in a tool kit, which it inevitably will, then the obvious result is that some of it will collect on any uncovered electrodes. I'll definitely take that on board and get a container I can seal.

Jeff

[Otto Nobedder]

I've never used anything but straight argon on steel.

Another member, RedIron881, does vacuum-tight work similar to mine, but on much heavier sections and on stainless, he uses a mix of 98% argon, 2% HYDROGEN, to get the same heat effect as Ar/He for aluminum.

All I can say, is give it a shot and see what happens. With the price of helium, though, the effect better be dramatic!

I might have to do some experimenting myself, as I have unlimited access to helium at work.

Steve

[gnabgib]

Hi all,
After all the drama over the cause of my problem, I've come to the conclusion that it was the wire type. At home I was using ER70S-4 but I should have been using ER70S-2, "SuperSteel" which is triple deoxidised. Anyway after all that I finally passed the #7 certificate.
Thanks, Jeff

[Otto Nobedder]

Results speak for themselves.

Congratulations!

[gnabgib]

Thanks, I almost didn't make it! On the 3rd pass of the test in 2G position I got a nasty gas bubble which I've never had before and I was about to throw in the torch. I decided instead to grind it out and continue....It definitely pays sometimes to hang in to the very end. Otherwise I might have been saying..."Oh to know better"

[nova_70_383]

i had an odd problem myself. the terrible looking weld appearance would really show up in the last 25% or so of the tank of argon. after fighting what i thought was me.... i had airgas check the bottle. they ran tests on on it and found out there was way too much nitrogen in it. i had got 3 tanks in a row that had this problem. not dinging airgas as they took care of me, but shows that yes indeed tanks get stuff in them thats not supposed to be in there!