root pass trouble and "arc control"

[Rowdius]

Tonight in school I retook the 1G bend test. I had passed it a month ago, but with easter break, and with being out with a hurt back, I hadn't been in school for awhile. Anyway, 1/4 metal, 3x3 inch coupons, 60 degree angle 1/16 root opening, 1/16 land on the groove. I started with 1/8th 6011 for the root pass set at around 80amps. Started good, had a good keyhole, but then it got away from me, started blowing holes in the work. Adjusted my amps down to 70-75 (can't remember) but still couldn't keep my key hole from turning into a horrible universe devoring blackhole of death.

I let that one cool, started another one with 3/32 6011 set at around 55amps. It was better, got good penetration, but not much of a keyhole. Once the first one was somewhat cool, I cleaned it up and filled in the hole and just started working both pieces.

The first piece passed the bend test, despite the hole I had to fill, didn't get a chance to bend the other. Do yall think I was running too hot on the first one? It seems like everyone else was running 1/8 rod, and every other welding machine I saw was set up around 90-100amps. My travel speed was fast, and I don't think I could have went much faster. I was running just a stringer for the root, no whipping, weaving, just swearing.
The only other thing I can think of, is maybe I didn't put 1/16 land on the groove. Now that I think about it, I just eyeballed it, so maybe it was more like 1/32 or something.

I sure wish I had the Miller XMT 304 I use at school here I home, though The arc is so much more smooth than on my old AC machine. If I tried starting 1/8 6011 at 70 amps here at home I'd stick it to the work a dozen times I think. The machine at work has a knob labeled "arc control." I've not messed with, as that I don't know what it is for. Could someone explain it to me?

[David R]

I will try.

Turning the arc control UP makes the puddle freeze faster and makes the rod dig a little more. (crisp)

Turning the knob down makes for a flatter bead with less spatter. (buttery smooth)

Try it at both extremes, then in the middle.

Keep messing with it until you can see what it does to your weld.

[Rowdius]

I will try.

Turning the arc control UP makes the puddle freeze faster and makes the rod dig a little more. (crisp)

Turning the knob down makes for a flatter bead with less spatter. (buttery smooth)

Try it at both extremes, then in the middle.

Keep messing with it until you can see what it does to your weld.

Thanks! Sounds like a nice feature to have. This is a basic class, so all I had to pass is the 1G, so I'll probably spend quite a bit of the next class just playing with the arc control while I'm messing around with the other positions. I was a bit afraid to mess with it before, as that given the limited time we have in class, I didn't want to mess up my test sample somehow and not have time to get one ready to bend.

[lotechman]

The arc control changes the 'slope" of your amps/volts curve. When set low (soft) changes in arc length only make small changes in amperage. When set to crisp increasing arc length will decrease amperage. Push in close and the amperage goes up more. This helps when you are running your root allowing you to whip and pause along. In effect you are changing the amperage of your machine by having a long or short arc. When running on the flat with iron powder rods (E 7014) you will find a soft setting is better.
Not to rag on your instructor but you should have understood this in your theory classes before you went under the hood. Not understanding the theory lengthens your time in the booth.

[z0diac]

Remember that you don't always have to turn your amps up/down with stick - just keep a much shorter arc length and that will decrease your voltage. The longer the arc length the more air resistance = more heat. Keep the end of the rod right down close in the gap and you won't burn through as much.

[mb_welder]

1/16" opening? Try a 1/8" land and root opening running around 65-70amps with 1/8" and keep the rod in der! Crank the arc force for the root and turn it down to around 30%-50% for the rest. :)

Any reason for running 6011? I've never actually tried 6011, we've always rooted with 6010.

[gizzardgutz]

65 to 70 amps, 1/8 rod, nickel wide land, dime wide gap is how I was taught 30 years ago. It has always served me well. 6011 is an AC rod while 6010 is a DC rod. Same rod, different flux. Practise, practise, practise. I'm real partial to DCEN.

[Rowdius]

Remember that you don't always have to turn your amps up/down with stick - just keep a much shorter arc length and that will decrease your voltage. The longer the arc length the more air resistance = more heat. Keep the end of the rod right down close in the gap and you won't burn through as much.

Thanks. I think I was keeping a fairly short arc (well, at least not long arcing it) but I will have to try to really, really make sure I have a short arc the next time I play around with it to make sure. When I did the 1G a month or so ago, I didn't seem to have a problem, so maybe I did long arc this time or something.

1/16" opening? Try a 1/8" land and root opening running around 65-70amps with 1/8" and keep the rod in der! Crank the arc force for the root and turn it down to around 30%-50% for the rest.

Any reason for running 6011? I've never actually tried 6011, we've always rooted with 6010.


65 to 70 amps, 1/8 rod, nickel wide land, dime wide gap is how I was taught 30 years ago. It has always served me well. 6011 is an AC rod while 6010 is a DC rod. Same rod, different flux. Practise, practise, practise. I'm real partial to DCEN.

The instructor wants 1/16 root opening and 1/16 land, so that is what the instructor gets. Not that it really matters now that I've passed it. We are only required to do the 1G to pass the class. The 2-4G are just optional. So, when I set those up, I'll follow yall's suggetions of opening things up a little.

I used 6011 mainly because the storage room got locked when the instructor was out of the lab, and I could get my hands on some 6011. It runs just fine on DC. Besides, that is what I have to use here at home with my AC welder, so I'm comfortable with the rod anyway. The first time I did the 1G I did it with 6010.

The frustraiting part about this class is that it is scheduled to last between 6:30PM to 12:30AM, but it is on a friday night, the instructor has a class at 6:00AM the next morning. No one seemes disappointed that we tend to leave around 10PM, but it does make it hard to get coupons cut, prepared, welded, cleaned up, and then cooled off to bend. Last time I just cut and beveled my coupons at home, so I could go straight to welding once I got to the class. Made things a little better. The class is almost over, but I think I'm going to take either a TIG class or a layout class next sememster.

[ol' Stick Guy]

Thats Bull**** my man, I assume your paying for this class, If you're keen to learn this Instructor should be willing to spend the time at least another 1&1/2 hours to accomadate you and any others who may want to learn rather than swilling 2.4 beer. I agree with z0diac.

[gizzardgutz]

I didn't get it right the first time, 6011 is actually AC/DC, where 6010 is DC only. 6010 will also run on AC, but it ain't purty!! You need to do it like the instructor says, don't mean that's what you'll be doing in the field, or how you'll be tested prior to the job. Could be he's teaching you to pass a test that one of your local shops/jobs require. You'll get there, hang in!

[Rowdius]

Thats Bull**** my man, I assume your paying for this class, If you're keen to learn this Instructor should be willing to spend the time at least another 1&1/2 hours to accomadate you and any others who may want to learn rather than swilling 2.4 beer. I agree with z0diac.

If I were to say something, he'd probably keep the class till after midnight, but no one else in the class sees leaving early as a problem. It is not a big deal to me. I mean, I am paying for this class, but at a discounted rate. I took it "not for credit." I'm not planning on finding work as a welder, I just wanted to learn to learn, and to build/fix stuff here on the homestead. I have most of the tools here at home that they have in the lab (though some of mine are not nearly as nice) so, I can take what I have learned up there and expand it at home. Now, if I was trying to get a job with this class, or if I didn't have my shop at home, I'd probably be pretty mad.

Rereading what I've written, I've made the instructor sound pretty bad. He's not, really. Just really busy between teaching highschool kids during the week, plus a friday night college class, and a saturday morning college class... Not to mention the farming. I've learned alot from him, and he's let me use the plasma cutter, which is not part of the class. It just might be better if his schedule was not as crazy the next semester.

[Rowdius]

Thanks everyone for the great advice! I tried several of the suggestions tonight, and did not create blackholes of death in my root pass. Shortening my arc worked really well, though I felt like I was going to push my rod through the gap. DCEN ran beautifully, and left the perfect amount of penetration on the root pass.

Bent a sample on vertical up. The root up passed, but the root down failed with a tiny, tiny crack at where the toe of the weld would be. I think I did not pause long enough at the toes and locked in some slag. Either way, I was pretty happy with the root pass.

Thanks again for all the help.