[ptig185]

Hi,
I'm practicing my aluminum by welding on some 1/8" plate and welding a pipe to a plate. The plate is 1/8" and the pipe is about 0.075" wall.
I've also tried some pipe butt joints too. I'm having issues with the puddle not wanting to form very well. I get 2 small puddles, one on each side of the tungsten. It seems I have to really let the heat soak a long time and risk blow through to get the single puddle.
The best results I've had is by pushing the filler rod in (not dabbing the front of puddle) to get the puddles to join.
If I dab the puddle front, the filler wants to ball up.

On my Precision TIG 225:
I sharpened the 1/8" tungsten to a needle point (Weldcraft WP-20 torch)
I set about 100 amps AC with pulse rate at max and Auto balance.
I set the tungsten about 1/4" out.
Gas flow about 20 CFH.
3/32 filler rod.

It seems on any joint, I have troubles with 2 puddles forming instead of one.

What Am I doing wrong?


Thanks,

Brian

[Otto Nobedder]

Hi, Brian.

You're not doing anything wrong. The HF arc is drawn to the closest points on the work, witch is always outside the corner on a fillet, no matter how close you get the tungsten. I tend to hold the tungsten very close until I get two puddles close together, then feed in some rod, as you said. Once you have that bead of filler started, it's now the closest thing for the arc to hit.

In your case, I'd keep the heat more on the plate, as the .075 wall pipe (tube?) is more prone to blowing out, while the plate takes longer to bring to welding temperature.

Keep practicing. I'm geting paid VERY well right now to weld aluminum tube and pipe.





Steve

[kermdawg]

hey otto, is the profile on the weld beads suppose to be like that for aluminum? I thought it was suppose to be 1/16 above for reinforcement. Im curious if your application is differant. looks bitchin though :) wish my aluminum beads looked like that..specially since i havnt tigged for almost a year now heh

[Otto Nobedder]

Kermdawg,

That weld is sch. 10, but has a backing ring of equal thickness, so the reinforcement is on the inside. Additionally, it's a two-pass weld with a very hot root (thanks to the backing ring), allowing for a very broad tie-in (I've had to cut a couple apart).

BTW, that's three inch pipe, so I'm probably right at a sixteenth anyway.

Thanks for the compliment. Since I'm still my own worst critic, It's reassuring to hear positive feedback.

I've got a pic or two from the instrument tubing I've been doing this week. Scary stuff. 6061 T-6, 3/8" .049 wall, socket weld. I'll try to post them soon.

Steve

[Otto Nobedder]

What the heck, that was easier than I thought.

Here they are. This is where pulse mode comes on handy; It helped me keep heat under control on this thin-walled stuff. Overheat a joint with ANY stress on it, and it will fall apart like a beer can in a bonfire.

Steve

[jpence38]

Steve,

That's some good lookin' work you do. What's the application for the product you are making?
I would give up my business in a minute if there was work like that in my area. (Although it is nice to call your own shots.)

[Otto Nobedder]

Thanks, Jim,

I've actually been getting praise on my tube bending from AirGas' instrument fitter foreman, who brought his own crew. Though I've done some before, I'm not an I.F. by trade. I figure if you know what radius you're bending it's just fitting very small pipe, and I have a tendency to be a perfectionist.

While Airgas is the client, My employer is ULG, and I'm actually working in a nice brand-new shop owned by Herr & Sacco. They've been in business for years doing ASME coded work, sanitary and food-grade piping, and other high-skill projects. I'm still amazed I was lucky enough to land this contract. I'm expecting to install this thing, too, so there's another six months of work at the same wage, and probably a bit higher per diem.

I'm building a "cold box". This is a new design, and in fact the prototype (hopefully, a working prototype). The goal is to separate liquid Argon, Oxygen, and Nitrogen efficiently from a single unit. This one is destined for Dow-Corning's Hemlock Semiconductor plant in Clarksville, TN. If this one is as successful as the engineers predict, there will be three or four more to build in the next few years. If I do another one, though, I want a lead position. This job was done with no sense of sequence at all, and virtually all the isometrics have errors in them--mostly incorrect takeouts for socket-weld fittings, leading to incorrect cut-lists. There has been rework on most of the lines under 3". I'd like to be in a position to prevent a lot of that. As you saw in the pictures, there's a pile of drawings for this that would founder a billy goat.

I was SO relieved to start on the instrument tubes; I'd been spooling pipe since the second week of July, and was getting really tired of working on the bench building from ISOs. There are no drawings for the tubing, just a set of specifications, so I actually have to think and make decisions, which makes the work much more interesting.

On a side note, we stopped early today for the company's open house. AirGas brought their O.C.C. bike, and the big boss brought his top-fuel dragster. I'll have to post a pic or two when I have time to upload them.

Steve

[jpence38]

I can definitely feel your pain on the engineering fiasco when it comes time to go from paper to reality. Sometimes it makes you wonder why they have engineers at all at times. You would think that building something that big, they would have had some kind of assembly procedure in place, but then again we are talking from paper to reality. When I hear things like that, it brings back nightmares of alot of my days in the shop. I would definitely look for a lead position if the other units are a go after having to practically do the engineers' job.
I would really like to see some of those pics if you get time. I have watched practically every episode of O.C.C and haven't seen the one with the Airgas bike. I wonder if they aired that one?
Where are you located?

[Otto Nobedder]

Hi, Jim,

I'm working in PA, but about to go home to LA. Just bought a work truck from cragslist. Had my wife and a mechanic friend check it out, it's one hell of a steal. Numbers match up, and she's already got it licensed and insured so I'm ready to go to the next job.

Here's two pics of the OCC AirGas bike, one with me on it. I don't remember seeing this episode, either. I might have to check the website and see if this one aired. If you'll notice, it's an old-school hardtail chopper, so probably built by Sr.

Steve

[jpence38]

Steve,
I would have remembered that bike if I saw it on the show. Looks pretty cool. Definitely the traditional style. As you said, it was probably done by Sr.
Where abouts in PA are you? I live right on the western PA eastern OH border.

[Otto Nobedder]

I was working in Mt. Joy, about a half-hour east of Harrisburg, so probably 5 hours or more from you.

Looks like I'm not going home after all. I'm leaving in an hour or two for Binghamton, NY, anout three hours straight north of me, to supervise some flood cleanup at BAE Systems. Should be there about 30 days, then home.

Steve

[jpence38]

Flood clean-up??? Are you overseeing repairs being done to the facility? The 30 will go quick. Then homeward bound.
When it comes time to go home, if you go back down 81 to 80 west, you are welcome to stop by and let me show ya some Northeastern Yankee hospitality. I live about 1/4 mile from exit 229 on I-80 in Ohio.

[Otto Nobedder]

This job looks to be simple grunt work, with a bunch of $10/hr local laborors. Unfortunately, a competing company seems to want start a pissing match with us.

However, when they brought in two busloads of Koreans waving green cards to a facility that builds secret shit for the military, they didn't make a real good impression. They're here simply through nepotism.

My primary assignment for the next several days is to keep my eyes and ears open. Counter-espionage, if you will . I'll be looking for the people attempting to sabotage any company here, and my own in particular.

I'll have to look at my route options when I roll out of here. That's an enticing invitation, and might not be much off the direct route at all. I'll have to dig out my atlas and have a look. (Yeah, while I have a lot of technology, I still prefer a M.A.P. to a G.P.S. )

Steve

[Otto Nobedder]

Bump.

I'm bringing this to the top for zeb, so he can see the pictures.

Steve

[capozzoli]

Hey Otto, great looking welds and your explainatons are very well written.

I see Airgass is looking for more combo welders. I was thinking of sending my resume.

On your aluminum pipe weld do you dip or do you burry the rod and drag? I have a lot of luck with the burry and drag techniquie.

[Otto Nobedder]

Thanks.

It was all dip, as it was x-rayed. I wanted to see the keyhole, the melt, and watch the dip fill the puddle.

Steve

[capozzoli]

That makes perfect sense.

I have never welded Al pipe with a backing. Im either welding couplings on tanks or pipes.

May be a stupid question; but, the backing sleeves into the pipe? Then the key hole opens up off of the backing plate?

[Otto Nobedder]

The pipe is cut with a bevel and land, just like for a butt-weld. The backing ring does fit inside the pipe like a sleeve. When welding this, you're looking at a couple things. You want to see the lands break on each side like a keyhole, and a puddle form on the backing ring. When these tie together forming a common puddle, it's time to feed some rod, then move ahead.

I found it very challenging at first, but it became natural after a while.

Steve

[capozzoli]

Interesting. I want to try it. I have some welding tests coming up. One of which is aluminum pipe, I think? I dont know if it will be open route or backing strip. Trying to get the info.

All this talk reminds me of a place I worked at briefly years ago. It was aluminum pipe welding with all kinds of fittings. It was piece work and a very fast work environment. I was pretty fast but nothing like some of the guys there. I was amazed at how fast some of these aluminum welders worked. They had their machines cranked and wrapped a weld around pipe in a matter of seconds. If you happened to get in the way of one of these guys you would end up in the weld.