Pipe Welding on Steel

b4autodark said:
Not in the bay area, Minnesota. First off let me tell you how it happens "on the job". Your set up with gap and land looks fine, you have surely found out by now that pipe is not round! If your coupons both come from the same length of pipe it makes it easy to line them up and deal with ovality, otherwise rotate them to get your best fit - up.

On schedule #40 pipe the root pass is done with 1/8" 6010, not 3/32". never a downhill root on pressure piping 12" diameter or less always uphill, less chance of slag inclusions.

The hot pass will either be done with, depending on the prescribed weld procedure, 1/8" 6010 or 3/32" 7018, both will be run uphill.

The cover pass will be run with, also depending on the prescribed procedure, 1/8" 6010 or #/32" 7018, both will be uphill as well.

The reason for 1/8" 6010 and 3/32" 7018 is that both can be run at the same amperage (about 90 for starters). You don't want to have to jump out of the ditch and run back to your welder to adjust amps between the root and hot pass and cover pass. Minor amperage adjustments are accomplished by varying travel speed and arc length, you will get used to it.

Just a couple of observations. You have to hurry so fast with your root because you are using 3/32", 1/8" will deposit more filler material at a slower travel speed. You are "outclassed" by 1/8'' 7018 in a small bevel. The hot pass should be level with the parent metal and the top edges of the bevel should be visible and not eroded. When doing the cover pass the electrode should hesitate centered on the edge of the bevel long enough to fill the puddle and then move one electrode diameter uphill and hesitate on the opposite bevel.

I am not just picking these rod diameters out of thin air, they are the industry standard and will be the same for every test. Stringer beads will be used on horizontal welds for the cover pass. You have to have patience and walk before you can run. I wish I could spent a few hours with you in a welding booth.
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So no downhill welding on the root. Got it. I see that I continue to do more things wrong than right.

So the cover pass is a single bead (maybe a weave)? My cover passes have 2 beads. I will post a photo.

I did not understand “outclassed” (by 7018). You mean the 1/8” should be 3/32”?

I did see that pipe is not round. Mine is even less so because it has been tightly clamped in a 12” 4J independent to make the coupon.

I am going to need to figure out a way to tack the pipe that minimizes ovality and yields a more consistent gap. I was trying to gap to 1/16”, and I ended up with up to 1/8”. Very tough to lay a root in a 1/8” gap with a 3/32” rod.

Finally (for now), the lands on my coupons are not consistent. This is due to the 4J independent chuck distorting the pipe. I need to have the jaws tight because I am clamping the work from the inside & I don’t want the workpiece to fly out (as has happened with 4” pipe in a 3J universal chuck which is exciting). What size land should I aim for? I tried for .050” which burns away pretty quickly with 3/32” 6010 at 50 to 60 Amps.
 
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I know that there are multiple issues here, but it is what it is. Obviously a lot more work to do.

1D7D0E67-AD20-4286-B7A1-34273AB8DFB2.jpeg

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This is 1/8” 7018 Lincoln Excalibur at 110A, 30% DIG on a Miller Dynasty 210DX.
 
OK, you should have 1/8'' land, and 1/8'' gap. You are using 1/8'' 6010 electrode on the root pass at about 85 amps, depends on how the machine runs, I can't comment on ''dig''. Forget about using 3/32" 6010 for the root. If you want to learn how to weld pipe so you can pass a test it has to be done according to procedure, if you just want to stick together two pieces there are many ways to do it.

Cover pass should be a slight weave, single pass, uphill.

By outclassed I meant to big of rod for what you are trying to accomplish, to high of deposition rate, to hard to control. Decrease diameter to 3/32''. Use the same setting on your machine for 1/8'' 6010 and 3/32'' 7018. If you don't have any 3/32" 7018 on hand stick with 1/8" 6010, forget about 1/8" 7018 it is to hard to control for the weld you are trying to do in 3 passes.

You may want to try setting the coupons lengthwise in a piece of angle iron to line them up with your spacer rod in between them held together by a couple welding magnets till you get a tack or two in. Space them at about 5/32" because the gap will shrink after you tack it.

Before to long you will be able to beat a land on with a hammer and do a perfect root. Don't laugh, I've had to do it!
 
1" is waaaay to long for a tack!

Are you already skilled in straight, horizontal position? If not, master that first!! Back when I taught, we used 1/4" hot rolled strip to learn on. We had a jig that set the gap right. Tack the ends and go.
I'm not a "drag the rod" proponent. That said, the most common thing I would tell my arc welding students was "closer!" I could tell by the sound even from across the room.

Sent from my SM-G892A using Tapatalk
 
erikmannie said:
In my excitement to get welding, I skipped over the part where I plan the work.
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That made me LOL!
Even at over 50 years old I still sometimes catch a glimpse of my youthful exuberance over a project.
I hope I , no "WE" never totally lose that.

@b4autodark thanks for sharing your expertise! That's what makes this site great!

-brino
 
Keep at it, it will get easier. The porosity is from to long of an arc. It's easier to control with 3/32'' electrode. Most of the big slag inclusions are at stop and starts I would imagine. It will get better. It only took me a couple flatbed semi loads of rod to get decent at it.

Keep posting the pictures.
 
Erik,

If you made a solid plug, really just a disc with an OD that is a slip fit into the ID of the pipe, would that allow you to grip the pipes from the OD instead without as much movement?

Obviously you'd need a different plug for each pipe diameter.
I wonder if the pipe would be too oval to make this practical.....

-brino
 
Here the the 10” I.D. pipe in the 3J scroll chuck. I prefer a 4J independent (more clamping pressure!), but this is fine.

A9CAFB72-89F1-47DA-B8DA-F0E126574794.jpeg
 
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