Vertical butt welds

[ElDiaOctavo]

Can anyone give me some advice on how to do vertical butt welds?

At school I'm running 1/4" plate, 1/4" apart with no bevel and am required to fill the gap in one pass.

I have been using a MM200 on low range, tap 4, WS of about 28. I switched to tap 3 and lowered the WS to 22 and that seemed to allow me more "hang time" to fill the gap...but at the expense of penetration.

I know it's an art...but my instructor is not helping me dial in on this. He's a nice guy but we're not connecting for some reason. I could sure use some guideance.

[Pangea]

If there is no requirement against it, I'd run the root pass down and the cover, up.

[ElDiaOctavo]

The requirement is to fill the gap in one pass.

Even so, there is no bevel and without bevel I don't understand how I would do a root pass - the gap is 1/4" wide.

[hockeyguynick]

Hmm... it is a good thing to learn, as most schools give you perfect conditions, but in the real world, things are not always fit up perfect. I've had to fill in gaps twice that big in the past, and its not the most fun thing to do, especially vert.

What kind of process you doing? solid wire mig, flux core, dual shield? I try to run more on the hot side than the cold side to ensure penetration, but you have to hold on each side a bit longer to avoid undercut.

What problem are you having exactly? lack of fusion, undercut, rollover? If you can get a pic, and better description, you will be able to get a much more helpful response.

[ElDiaOctavo]

I'm using GMAW with a MM200.

Because we have limited clamping fixtures, I tack the two plates together on the table then clamp in a vertical clamp. I begin low and work upwards. I have been using tap 4 and a WS of 28 and it gives pretty good penetration but at the expense of piling up a mound of bead on the working side. Also, if I describe an arc motion - like drawing half moons - across the gap, it seemed to get worse...more bead pile up. So then I tried just working the arc back and forth inside the gap. That did OK but I seemed to lose penetration and still got a pile of bead.

So I switched the tap 3 and a WS of 22 and tried to work the arc back and forth inside the gap area with the wire stick-out as high up on the puddle as I can hold and maintain contact. That was the last thing I tried last week.

I don't know what lack of fusion, undercut, and rollover are so I can't describe what's happening in those terms. But I've got class tomorrow night and I am sure open to suggestions. I'll take my camera, too, and see if I can get pics.

[mikecwik]

im just a hack but dont see the point of this test period, let alone to a student that lacks some simple welding terms. the test does not seem to stack the odds in the favor of the welder.

not that they would have much meaning to the thread i dont think to begin with but when facade settings are given they dont have much meaning. i dont know what tap 4 is on the machine nor what 28 is or how true they may be.

the test sounds so goofy i might be tempted to use low settings uphill with a downward gun angle.(i did state hack in first paragraph)

[Sberry]

I will see if I can run one tomorrow, need to find my glasses. Its a good thing to know how to do.

[Pangea]

After reading the original post again, I have to wonder what the whole point of the test is? That's too much of a void to fill up in one pass and make it a decent weld. I think your teacher is running out of stuff for you to try.

[ElDiaOctavo]

It may seem pointless, but it teaches you a lot about how the weld process lays metal down. It also taught me to stop when the weld wasn't going well and re-assess what I'm doing.

I've done a couple of these welds about five inches long successfully with penetration all the way to the back of the gap and without excessive build-up on the front. I can do them horizontally all day long. Vertical is just very hard to do. It seems to take an ultra-steady, sure touch.

But I guess I'm wondering if there is something I'm missing, some technique that I don't understand or some machine setting that might yield better results.

[Roger]

Can you make that weld standing on head using mirror to see weld?

[SAWDADDY]

You can't weld air, ignore the gap, just skip across it as fast as you can. With the opening that big I would put the wire right in there on the "face" of the edge (a little way, like .050 deep) do a quick one-two count, (not "one thousand two-one thousand") then swing it to the other side & same thing. Keep your wire just skimming the top of the puddle as you move. You will likely see some bulge or sag on the working side, that is a lot of metal to pour in and expect it to sit still till it freezes. If you don't like the amount of sag then turn down WS as low as you can get away with, &/or try a lower tap. If you want it to look nice, grind it when done. clamping a temporary backer would be a good idea too, you would probably do it in the field so it sure ain't cheating in the classroom.

that motion will require a large hand movement, the tip will only move a little but your hand will need to make a angle change more than 90°.

even better idea, ask your instructor to get under the hood and demonstrate while you watch under your hood, you're PAYING for classes right? You don't get something this is his job, it's what he is there for. Even if you don't "click" you can learn more from SEEING him do it than from him telling you or on any forum. Are you the only one that is struggling on this?

[ElDiaOctavo]

clamping a temporary backer would be a good idea too, you would probably do it in the field so it sure ain't cheating in the classroom.

even better idea, ask your instructor to get under the hood and demonstrate while you watch under your hood, you're PAYING for classes right? You don't get something this is his job, it's what he is there for. Even if you don't "click" you can learn more from SEEING him do it than from him telling you or on any forum. Are you the only one that is struggling on this?

Thanks for the excellent input - I had another class Monday night and tried the lower tap and ws setting. My work is improving but, man-o-man do I have to concentrate on it. Feeding it less heat and wire gives me time to "work it" a little.

If I were to use a backer, how is this done and what kind of material do you use??

Also, I asked the instructor to do just that...show me. Frankly his stuff didn't look any better than mine and I couldn't see anything in his technique that was helpful.

I'm the only one struggling with this because there are only two students...me and a 16 year old kid that is there as part of an industrial design program he is taking in high school (good kid - kinda quiet and teenager weird, but he's on the right track). He does not do the same things as I am doing - no idea why.

I'm going to keep working the low voltage, low WS route and see where that goes. It's for sure tap 4 and ws28 didn't work!!

[rlnash]

ELDiaOctavo -

Your not alone - In class I have been working on Vertical with 7018 stick - I keep getting globs - I have been trying a faster run with the first pass - maybe I am setting it too hot. When I weld flat they look good. The class is almost over and I want to make some improvement. Do you guys run less heat on a vertical then you would on a flat weld?
Rick

[ElDiaOctavo]

Dude, I cannot imagine doing vertical butt welds with a stick...but anything you learn, let me know.

The only thing that helped me so far was turning down the voltage and wire speed. I don't know how that relates to stick...I'm just learning.

[Sberry]

I haven't had a chance to run a couple plates yet but its a weld I use frequently, fixing cracks, filling gaps. The ones here are stick, 1/4 open butt, no bevel. One vert, second one the backside, 3rd overhead overhead. E6011. These are not meant to be perfect examples but to demonstrate technique.