[Charles]

Hey guys, I finally got the power run for my new welder and have been trying to do Jody's steel drill for the past two evenings. I have no prior TIG welding experience so I'm starting from scratch here.

I'm welding on what I believe to be some A36 mild steel that I got from the scrap bin at work. It has freshly machined surfaces, so there's no scale, rust, or dirt on it. I'm prepping it with some scotch brite and then wiping clean with acetone to get any residual cutting oil off the surface.

As far as machine settings and torch setup, I'm on DC-, 2T setting and running around 100 amps. 10 CFH argon with a 3/32" 2% lanthanated tungsten with a gas lens and #8 cup on it.

I've run several experiments so far trying to isolate variables in the problems I've been having, which are the following:

-With a 1/16" tungsten, I'm getting arc flashed. The arc establishes and is clean / stable, then it will flash up real bright for a second or two, then go back to normal. Going to a 3/32" seemed to solve this problem.
-In going to 3/32", I'm having some serious porosity problems. Last night I wasn't adding any filler wire, and my welds look like they're not getting any shielding at all. Porosity and brown crap all over the bead. I checked and double checked my gas flow and there's definitely gas flowing out of the torch head. Increasing gas flow makes the problem worse.

Could there be residual contamination inside the steel, or is there something wrong in my weld prep or machine / torch setup? Any tips or things to try are greatly appreciated...getting pretty frustrated that I can't do such a seemingly simple thing.

-Chuck

[Oscar]

What is likely happening is that there is a leak in the argon flow path. As the argon flows, it "siphons" air from the atmosphere into the tubing/fittings, thus delivering oxygen to the tungsten/weld pool. Just feeling if there is gas coming out of the torch doesn't tell you that it is pure argon. The fact that this gets worse with increased flow tells me that this is likely what is happening.

The leak could be:

from tank/regulator to machine
or
inside the machine
or
from machine to torch head

So now you need to TRIPLE check everything. Telling us HOW you checked wouldn't hurt either.

[Superiorwelding]

-With a 1/16" tungsten, I'm getting arc flashed. The arc establishes and is clean / stable, then it will flash up real bright for a second or two, then go back to normal. Going to a 3/32" seemed to solve this problem.
-In going to 3/32", I'm having some serious porosity problems. Last night I wasn't adding any filler wire, and my welds look like they're not getting any shielding at all. Porosity and brown crap all over the bead. I checked and double checked my gas flow and there's definitely gas flowing out of the torch head. Increasing gas flow makes the problem worse.

Could there be residual contamination inside the steel, or is there something wrong in my weld prep or machine / torch setup?

-Chuck

Chuck,
Don't get to frustrated, we all go through a learning curve and still to this day have problems now and then.
If you could get pics up that would be great.
The two things I would check is if you are increasing gas flow and it gets worse, I would have to say that you are getting oxygen sucked back in through somewhere in your lines. It is also possible, although not likely given your low CFH, that you are sucking oxygen in at the nozzle.
Second would be that this was a machined part, thus there will be a problem with the cutting fluid. Although it seems that you are cleaning it well, try a different approach and see what happens.
-Jonathan

[Charles]

Thanks for the suggestions guys - I'll do another leak check tonight and grab another piece of steel and see if it does the same thing.

[ljdm1956]

Definitely not an expert, but I would think 10cfh is to low. Try increasing it to about 15 - 20?

[AFSATCOM]

I typically run 12-14 cfh with a 7 gas lense. But he already said he increased flow.

[Charles]

Is the point of a gas lens to improve coverage with less flow, or just reduce turbulence? Ideally what should my flow rate be to provide adequate shielding? Since I'm just practicing I didn't want to have it cranked and wasting gas, so I set it at 10 CFH as a starting point.

As mentioned above I did try increasing flow to ~20 CFH, and the bubbling/sputtering as I moved the torch along got more severe.

[AFSATCOM]

I have run at 10cfh. I just keep it at 12 cause it gives me a little piece of mind that it won't get disrupted as easily. Just out of curiosity is your tungsten turning black?

[Charles]

Yes it is

[AFSATCOM]

Yes it is

That's what happens when oxygen hits a white hot tungsten. Find the leak that others have pointed out.
And be sure to remove all the black off that tungsten before you fire it up again.

[Charles]

Yes it is

That's what happens when oxygen hits a white hot tungsten. Find the leak that others have pointed out.
And be sure to remove all the black off that tungsten before you fire it up again.

Could that explain why the 1/16" tungsten was arc flashing? Tungsten reacting with the oxygen?

[AFSATCOM]

Yes it is

That's what happens when oxygen hits a white hot tungsten. Find the leak that others have pointed out.
And be sure to remove all the black off that tungsten before you fire it up again.

Could that explain why the 1/16" tungsten was arc flashing? Tungsten reacting with the oxygen?

Dunno about that. I usually keep a delay set on my hood to mitigate momentary interuptions though

[Oscar]

Is the point of a gas lens to improve coverage with less flow, or just reduce turbulence? Ideally what should my flow rate be to provide adequate shielding? Since I'm just practicing I didn't want to have it cranked and wasting gas, so I set it at 10 CFH as a starting point.

As mentioned above I did try increasing flow to ~20 CFH, and the bubbling/sputtering as I moved the torch along got more severe.

Since you are just practicing you should be using it to save argon gas. So long as you are not going crazy with the stickout, use proper torch angle, in a 100% draft free area, welding in the flat position, and maintain a proper arc length, you can get away with 10 CFH with up to about a #8 cup. But if any of those variables are perturbed, then you may or may not get away with 10 CFH. You first need to get rid of your leak issue.

[RichardH]

-With a 1/16" tungsten, I'm getting arc flashed. The arc establishes and is clean / stable, then it will flash up real bright for a second or two, then go back to normal. Going to a 3/32" seemed to solve this problem.

That's probably your mask, presuming it's an auto-darkening one. The arc isn't getting brighter, your mask is turning off briefly. It's easy to have happen at low amperages, or with fewer sensors in the mask if your hands block their view.

Try adjusting the sensitivity, and increasing the delay (which will keep the mask dark for longer after it stops seeing an arc).

Cheers,
Richard

[Charles]

So I think I might have solved the problem tonight. I did a couple things:

1) went back through my machine settings. there was no pre / post flow setup, so I put in about a half a second pre / and 5 seconds post to protect the tungsten
2) went from a #8 cup to a #6 cup
3) bumped it up from 10-12 cfh
4) swapped regulators - I think this is the big one. I checked all my connections and snugged them up, but that still didn't solve the problem. I threw the one on from my mig welder which is known to be good and that took care of the porosity.
5) bumped up the sensitivity on my helmet and increased the delay. no more arc flashing with 1/16" tungsten

Arc is smooth and stable now, no porosity, tungsten is staying clean.

Now I just need to practice!

Thanks for the help guys

[Superiorwelding]

Charles,
I am glad you figured it out, although I feel kinda dumb for not asking about your post-flow. Get some beads ran and post the pictures.
-Jonathan

[Charles]

Charles,
I am glad you figured it out, although I feel kinda dumb for not asking about your post-flow. Get some beads ran and post the pictures.
-Jonathan

It's something I should have checked as well, but my excitement got the best of me and I overlooked it.

I got some good seat time in with it last night - machine settings unchanged for the most part. I was doing Jody's steel drill padding beads back and forth, switching hands every few passes. I'm right handed, and oddly enough I feel more comfortable welding left handed. Obviously still a tremendous amount of learning, work, and practice to do, but at this point I'm happy that I got over my first speed bumps and at least got the machine running smooth now.



I think more than anything I was focusing the most on maintaining a consistent arc length. Starting out I was dipping my tungsten a lot. Doing that a lot less now and the torch feels more stable in my hands, but consistency and control obviously need a lot of work. Also, my filler hand is giving me problems - I'm having a hard time feeding the wire as I go while still maintaining control over filler placement. I've just been holding the wire in a fixed position and feeding it in, but I know this will need to change as I'm able to increase my travel speed in time. Any tips / practice techniques in particular you guys found useful to get over this, or is it just a matter of practicing it?

Open to any tips / criticism / suggestions!

-Chuck

[AKweldshop]

http://welding-tv.com/2013/11/12/tig-steel-drill/

Here's a good vid for you to watch.

~John

[Charles]

http://welding-tv.com/2013/11/12/tig-steel-drill/

Here's a good vid for you to watch.

~John

Thanks John. I've watched that video many times, but I'm still pulling things out of it every time I watch....even more so now that I have a little experience trying to do it.

I believe more practice is in order this evening

-Chuck

[AKweldshop]

http://welding-tv.com/2013/11/12/tig-steel-drill/

Here's a good vid for you to watch.

~John

Thanks John. I've watched that video many times, but I'm still pulling things out of it every time I watch....even more so now that I have a little experience trying to do it.

I believe more practice is in order this evening

-Chuck

I hear you on watching Jody's vids over and over.
Same here,
I've watched all of Jody's vids, many times.
~John,
Good Luck.

[Superiorwelding]

Chuck,
First I will say you are doing great! Looks like you are getting consistency down. For advice on how to feed your wire, I personally find it easier to not wear a glove on my feeding hand. I like the feel of the bare hand over the glove. This may or may not be a good habit to learn but it is how I do it on lower amperage welding. The most important thing will be hood time. It will come in time and you seem very determined.
-Jonathan

[brokeitagain]

Chuck,
First I will say you are doing great! Looks like you are getting consistency down. For advice on how to feed your wire, I personally find it easier to not wear a glove on my feeding hand. I like the feel of the bare hand over the glove. This may or may not be a good habit to learn but it is how I do it on lower amperage welding. The most important thing will be hood time. It will come in time and you seem very determined.
-Jonathan

maybe a very high SPF sunblock on bare hand? I know bare handed filler feeding is my preferred method but I must be sensitive to getting UV burn because my hands are always on fire after a practice session
I have been through two 125 cu.ft. argon cylinders and still practicing, not improving much since I began learning on my own but I hope to get better, I have a few pics posted of my first attempts, they are not great but I have seen much worse

[Charles]

Thanks for the suggestions guys. I'd like to get the technique down with gloves if possible - welding sunburn is not something I want to get into the habit of giving myself. It'll just take time I guess.

Burned through my first 80 cu.ft of argon and a half pound of 1/16" 308L filler. Lots and lots of practicing to do yet. In the mean time I've got to get my bottle refilled and set up a welding cart for it. I have one of these for my mig welder and got another one for the tig, does everything I need it to do: http://www.northerntool.com/shop/tools/ ... _200395734.

Perhaps I'll put up some more pics once I get rollin again.

[AKweldshop]

Charles,
Here are some pics of my hand from welding sunburn.
Don't do it.

First pic is 12hrs after welding.

IMG_1064.JPG (51.07 KiB) Viewed 2123 times

Second pic is 3 days.

IMG_1305.JPG (75.92 KiB) Viewed 2123 times

I'll get you a pic after one week.

Anyone want to guess what I was welding and for how long???

Thursday.

~John

[noddybrian]

It looks typical of propping a Mig torch assuming your right handed - takes very little time if the amps are high or the material is reflective - aluminum is especially bad though I don't recall you posting anything in that material recently - as to time - that is easily achieved in 5 minutes - maybe less if unlucky / in a difficult location especially if fair skinned - the more times you do it the easier it seems to catch you - I did it plenty when young & now can't go out in strong sun for more than a few minutes before this happens - except mine is worse as the skin comes up in large watery blisters that pop & get infected - it's a safety thing people tend to ignore - like the open shirt front burns - increases the risk of skin cancer as well I'm told - DON'T DO IT !