Mig overhead portion of tubing

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Finally got my .023 drive roll and wire set up. Tried some practice passes on the overhead portion of some 2" 16ga round steel tubing. As I came down the vertical downslope and transition to overhead, everything got real sloppy, but not typical spatter when you run out of gas or strike with no shielding gas. Or maybe I just didn't pick up on it as my focus is on struggling to smooth out my movement with regard to travel angle and the line.After a couple more tries, I DID run out of gas. I was at about 15cfh AR/CO2 75/25, is it typical to up the gas coverage on overhead for most gases, (except Helium I think)?Lincoln AC/DC 225/125 and WP17. 75A AC is for pipe thawing!HH 140 - new addtion 9/2012.I didn't agree, but hoped for Hope and Change.I got change for myself and my family: for the worse.This is the reality of: Barackalypse Now. Again.
Reply:Biggest issue I see with people who are having trouble with vertical and overhead is that they haven't learned to "see" and manipulate the puddle. The fact you are running downhill tends to make me think this might be your issue as well. I see a lot of guys who want to run downhill vertical simply because they can't control the puddle running uphill. If you can't control and manipulate the puddle, then chances are you will have a nightmare on overhead as well.Add to this the fact you are welding round tube. I frequently see guys who try to weld round tube like it's flat and don't constantly change the gun angle to match the tube circumference as they swing around the material. This added to a lack of control over the puddle will spell disaster.If you can't weld uphill and overhead on flat material well, that's where I would suggest you start. Start with vertical up on 1/8" material and keep at it until you can consistently make nice welds with no undercut, humping or irregularities. Then after you can do all the joints in vertical, move on and do the same drills on flat plate in overhead. Tube just complicates the equation. Save that until you have the basics down cold and can do these welds without thinking about it.Personally if I had to weld 16 ga tube, I'd start at the bottom and weld up myself. I find it easier to control in most situations..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:I was specifically practicing travel / gun angle and travel in general. I'm trying to get comfortable for out of position welds, like a muffler or exhaust section that has to be done in place. I just noticed the quality of the arc declined dramatically, which could be from my travel angle going way to steep as you said. I was just wondering if the volume of shielding gas was also a factor.I have been practicing vertical up and down; I'm getting much better and more comfortable with the mig in general. I kept burning through on the up so I worked on down until I got decent results (I'm pushing on both, and was using a practice piece of square .065 tube. I'll work on the overhead like you suggest, with 1/8". I agree I got ahead of myself.I did a little mig in class last year to be shown the basics. I've only been through a little of the flux core that came with the machine, one fill on a 40cf cylinder, and about 3lbs of .030 wire. I'm liking the .023 wire so far, as the my intended use for this machine is sheet metal.Lincoln AC/DC 225/125 and WP17. 75A AC is for pipe thawing!HH 140 - new addtion 9/2012.I didn't agree, but hoped for Hope and Change.I got change for myself and my family: for the worse.This is the reality of: Barackalypse Now. Again.
Reply:Picts always help along with the machine, settings etc. .023 wire and 75/25 will be the way to go with this most likely.As far as gas, usually if you don't see porosity, then your gas flow for the stickout is just fine. Note that just because you get porosity, doesn't mean the gas flow is wrong. Many times I see students who will unknowingly back the gun away as they weld, and thus loose the gas shield. It's not that the gas is set wrong per say, only that they increased the stickout.Keep in mind your stickout can help or hinder you with this. With mig, the bead will run "hotter" if you are in good and tight, and colder if you back off some. A good mig welder can fill holes and gaps in poor fit up or burn in a spot where things get too tight, simply by adjusting the distance of the gun from the work based on what he sees is going on with the puddle. It takes a good bit of practice to be able to do this however, especially if you are also trying to go around small diameter tube at the same time.You may find part of your vertical issue is that as you transition to vertical, you tightened up your distance, hence the bead got hotter. I often find students who will run a long stickout at the bottom of a vertical, then tighten up as they swing the torch and then have the stickout get long again near the top. This is because they rotate the gun rather than maintaining a constant gun angle. Most do it and never realize that they are doing so..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan