Bubbling TIG pool

[JRouche]

Been having a heck of a time. Welding some 1/2" hot rolled plate to some 2"x .250" square tube.

I cleaned the joint really well and tacked it up. That went fine. But when it came time to weld it I was getting alot of bubbling up of the weld pool. Like it was contaminated. Or like the gas wasnt pure. And there wasnt any oil or contaminants on the metal. But it bubbled up just like there was, yeah, I have screwed up and welded oily metal. But with that I can usually cook it off and get back to welding.

This stuff never cooked off. It would bubble up like a volcano and leave a nasty porous bead. The bead would actually grow up by about a 1/8", it was active.

So I started thinking my gas was bad LOL Yeah, I do get bad gas, just yesterday at the superbowl and the chili contest. Ooops, wrong story. But anyway. My argon bottle is about six years old since the refill. It was fine the whole time. I could try some other steel, that would rule it out.

I really think its the steel. This is new steel just bought from a large dealer. Industrial metal supply.

Anyone else see any steel lately like this. Could it be the steel. Oh yeah, it MIG welds just fine. In appearances, didnt grind out a weld to see. Im stumped... JR

[10KPete]

I'd be willing to bet that because the joint isn't back-gassed, or the flow through the torch isn't enough to help shield the back somewhat, you're getting oxidized junk from the back side.

But then I don't know what gap, current, filler, etc, etc........???

But that's my guess anyway!

Pete

[JRouche]

I'd be willing to bet that because the joint isn't back-gassed, or the flow through the torch isn't enough to help shield the back somewhat, you're getting oxidized junk from the back side.

But then I don't know what gap, current, filler, etc, etc........???

But that's my guess anyway!

Pete


Hey thanks Pete. The joint was a butt joint. The 1/2" plate was beveled at a 45 and butted up to the sides of the 2" tube which has a large corner radius. So my "double vee" was deep. There wasnt any need for back gas, wasnt anything to fill, no back voids. I wasnt welding into the pipe. An I have welded a few fitments where I just use the shield gas from the torch, no problems. Oh, and this was all new steel, no debris or anything on it.

This was the first time where I cranked up the current though. Had the 300 Hobart up pretty high. So I did think about not enough gas flow. Cranked that up to 25cfm just for the heck of it, usually stay around 10-12. No help.

I gotta say I hate TIG welding hot rolled plate. The hard crust is just nasty with junk. So I also made sure to remove all of it at the weld site to nice shiny silver steel, hate that HARD layer. Like glass, even a bear to grind off. But thanks Pete :) JR

[JRouche]

OK!!! Im a happy man. I gotta say. I have been stumped over this for a week now. Thats why I finally wrote here. I just couldnt figure it out. So anyway. I was laying in bed last night. Muddling over it. Then this morning I was laying there for a lil bit and thinking about it. Then BLINK!! The light bulb went on, and that was pre-coffee!! pretty impressive for me, nuthin gets done pre-caffine.

So I cleaned up, grabbed a mug of coffee and headed right to the garage. Looked at my panel. Yup, I see a problem. Broke out the angle grinder and dug out all the root volcanic rock that was my welded section.

Fixed my settings.. And layed down the nicest (for me!! LOL Im not a great welder like you guys) beads that I am used to. Yeah!! All pre-coffee still, Im still impressed.

So what happened.

I forgot. I DID change something besides the current level on the machine (250, not 300). I made a stupid beginners error. Flippin switches and turning knobs with no abandon. I should know better. I have had this welder for about 13 years now. Its still fairly unused, maybe five 250CF bottles of gas through her. And I am very familiar with all its controls.

But dummy me, went in there and adjusted one of the controls (Arc Force) from mid point to all the way to the digging side. The other side is "smooth". That wasnt my problem.

MY mistake came when I completely turned the dial next to it "A/C Balance" instead, from its mid point, DC, fully clockwise to the "Max penetration" side which is AC. And its not like throwing the BIG lever for actual AC welding of aluminum. But it does have some ac content instead of being a smooth DC. Its used when welding aluminum and on A/C. Just varies the wave potential a lil for either more cleaning (more positive electrode) or more penetration (more positive work) is the way I understand it. But while DC welding steel it should be left in the mid position which is DC. To me they should have that dial disabled while in DC mode.. Dunno.

So in my rush to get to welding I screwed myself for a few days. Not much fun. I can think of better things to do. Glad I figured it out and it wasnt the steel, I like IMS stuff. Actually have a truck coming tomorrow with some sticks of 1x2x.120". Happy welding, and dont do the stupid stuff I do and it WILL be happy welding... JR

[Liger Zero]

Yeah but if you don't do the stupid stuff then come on here and explain what you did wrong the rest of us learn nothing. :D

[10KPete]

That's great JR!!

I wuz gettin' all dug in for a long over-the-net diagnosis session which is the hard way to solve a problem.

Wheeooo!

Pete

[Berniep]

I was having the exact same problem on almost the exact same material. Fairly new steel not rusty and I cleaned it well. I know I had it set to DC and there is no ac component to my knowlege (HTP 201 inverter machine) until I turn the ac on. I never did figure it out for sure. I went back the next day and switched to a larger cup and it worked fine. But I had welded the same stuff with the smaller cup before with no problems.

[boslab]

worth bearing in mind that HRP can have a high dissolved oxygen content [seriously] normal levels for CRP [cold rolled plate] should not exceed 800ppm but a lot of cheap steel can have loads od dissolved oxy, to get rid of the oxy that is in the steel from the Basic Oxygen process the steel has to be 'killed' with aluminium [or other oxy scavanger] this is called AK steel ali killed, i used to really notice the composition when gas welding [but didnt know why] neutral flame and weld boil,settting flame slightly carbourising helped which should have told me what was going on.
Dissolved H2 can have the same effect as can N2 from the addition of low or high carbon nitrided ferromanganese, oxy [as i have been finding out recently] can even be in the Argon, we have a 20 ton tank in work which was suspect, after sticking it through a gas analyser [chromatograph] N2 and oxy was present, which the supplier fervantly denies [i appreciate virtualy nobody will have that kind of equiptment laying around, but if you supply a large lab then you generally watch your self] but even then the would not beleive or admit the fault, as has been stated on the other posts good shrouding of weld pool is vital, even a light draft can blow the argon away if you are using low flow, its irritating when it wont weld right but its so good when you flip up your lid and see a perfect weld [rare]
all the best
mark

[bobhdus]

Thanks for posting the problem and solution to the problem. I deal with this same porosity problem (or "weld titty") every now and then as well. I will say that in conjunction with your solution that in my own non-expert experience assuming that all other things have been checked and everything is clean etc..., when a gas bottle gets close to empty even though it shows on the gauge that it still has some gas left, the gas may not exhibit good quality characteristics. I also sometimes have to adjust the stick out of the tungsten electrodes angle to add or decrease the work to cup distance. High gas flow will cause the same problems as low gas flow due to the venturi it creates pulling in surrounding atmoshpere. I stay around 20-25 max. Good catch!

[JRouche]

Thanks for posting the problem and solution to the problem. I deal with this same porosity problem (or "weld titty") every now and then as well. I will say that in conjunction with your solution that in my own non-expert experience assuming that all other things have been checked and everything is clean etc..., when a gas bottle gets close to empty even though it shows on the gauge that it still has some gas left, the gas may not exhibit good quality characteristics. I also sometimes have to adjust the stick out of the tungsten electrodes angle to add or decrease the work to cup distance. High gas flow will cause the same problems as low gas flow due to the venturi it creates pulling in surrounding atmoshpere. I stay around 20-25 max. Good catch!


Thanks... I have about 500psi left in the bottle, I usually swap it out at about 150psi, gonna be soon. Gas is cheap for how much I use. Was doing some sheet metal today, oh I really love welding sheet metal. But my eyes and hand control isn't what it used to be, and heck, Im not even old yet :) Still love to weld though. Thanks for all the great replies!!!!! Still my fav forum to go to when Im having problems. Im not worried about folks jumping down my back talking about how screwed up I am, just need constructive help, and this place has got to be the best for that!!!!! JR