Critique some beads

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Had my Miller 211 for a couple weeks and am now starting to run some beads for practice before i start my first project of building a cart.I learned to OxyAct weld about 10 years ago and have not really done much MIG except a few years ago, so I will just say I have no real recent good experience.I know I will get roasted for not cleaning off the mill scale on this run of beads but I was excited and welded anyway. In the pics its hard to tell since they are pretty close up but this is a lap joint on 3/16" steel.I tack welded them in place, then ran the beads in a few separate runs as you can see from my starts and stops along the way.A few things I noticed while I was welding:1) At the start of the weld( you can see in the pics) I have a bit of wire that didn't fully melt into the puddle.2) When moving my ground clamp around I noticed it was slightly stuck to the weld piece. After that happened a few times I looked at the ground clamp and found the contact points are quite pitted and looks like they have been arcing. This was a used machine so I guess it was like this when I bought it. I plan on buying a pure copper clamp like on the old machines that you see so hopefully that will alleviate that issue. Could the first issue be caused by this poor ground connection? Seems like it could to me3) Brown deposits on the actual bead itself. Is this because I haven't cleaned the mill scale off?Machine was set to what the chart recommends for .035 wire. Wire speed at 60 and voltage at 5.5. Obviously there aren't true WFS or voltages. Gas flow was 20-25CFM. Any input is appreciated guys. Thank you!
Reply:Looks like your on the right trackThings to keep consistent while mig welding: stick out length, push angle with gun, travel speed. Your gas flow is in the ballpark.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Last two center beads look decent. The beads overall are much larger than I would expect for a 3/16" lap joint. Probably closer in size to what I'd expect to see on 3/8" or 1/2" plate.The 1st 2 picts look like the bead was way to far up on the upper plate. I'd expect to just see the edge of the upper plate burned off on a lap joint of this thickness. I'm not sure what you heat and wire speed were set at, but it looks like you might be able to turn it down some, or you need to speed up and or use less motion. A lot of the students at the tech school are completely enamored with using little "e"'s to weld. They end up with way too large a bead because they are in the same place too long, especially on a thin joint like a lap joint. To get a small bead and use that weld technique, they have to move very fast and keep their motions quite small. I tend to find they do better if they simply run a nice straight stringer instead.Watch the top edge of the upper plate, and aim the gun right at the edge of the two on the lower plate. You are simply "washing" the bead up onto the upper plate. A slight wiggle back and forth can help some, but not much. Maybe a 1/16" or less in motion. As you watch the upper plate burn back a 1/32" or so keep moving to stay even.If your settings are hotter with a higher wire speed, you need to simply move faster watching the puddle to gauge your speed..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:Looks like you like to weave your bead, now practice without weaving.Nice beads.
Reply:Originally Posted by DSWLast two center beads look decent. The beads overall are much larger than I would expect for a 3/16" lap joint. Probably closer in size to what I'd expect to see on 3/8" or 1/2" plate.The 1st 2 picts look like the bead was way to far up on the upper plate. I'd expect to just see the edge of the upper plate burned off on a lap joint of this thickness. I'm not sure what you heat and wire speed were set at, but it looks like you might be able to turn it down some, or you need to speed up and or use less motion. A lot of the students at the tech school are completely enamored with using little "e"'s to weld. They end up with way too large a bead because they are in the same place too long, especially on a thin joint like a lap joint. To get a small bead and use that weld technique, they have to move very fast and keep their motions quite small. I tend to find they do better if they simply run a nice straight stringer instead.Watch the top edge of the upper plate, and aim the gun right at the edge of the two on the lower plate. You are simply "washing" the bead up onto the upper plate. A slight wiggle back and forth can help some, but not much. Maybe a 1/16" or less in motion. As you watch the upper plate burn back a 1/32" or so keep moving to stay even.If your settings are hotter with a higher wire speed, you need to simply move faster watching the puddle to gauge your speed.
Reply:It's not that the "e"'s are "bad", it's just that that technique works better with thicker materials, or where you want to stay in the puddle longer. You need to adjust your technique to match the material and thickness. There's a lot going on you need to control all at once. The size of your "e"'s, travel speed, stickout length and so on. I just tend to find the simpler you make it, the easier it is for people to get the results they are looking for. The only time I really find making an "e" motion helpful is when people simply can not slow down and continually want to move too fast. The "e" shape gives them something to do while they wait for the puddle to build up.I tend to annoy students because I can make nice welds using a bunch of different techniques and settings, while they can't. It's simply because I've learned to read the puddle and adapt to what I see going on. In the end it's really all about seeing the puddle and reacting to whats going on..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:The hard brown deposits on the bead surface is oxidized silicon, i.e. "glass". Silicon is a consituent of your wire alloy used as an anti-oxidant. I've never understood where the brown crud around the weld comes from, like smoke stains, maybe from burnt "anti-spatter"??XMT304 (school)SP125+ (home)HF 4x6 BandsawGood judgement comes from experience and much of that comes from bad judgement.
Reply:Originally Posted by wireheadThe hard brown deposits on the bead surface is oxidized silicon, i.e. "glass". Silicon is a consituent of your wire alloy used as an anti-oxidant. I've never understood where the brown crud around the weld comes from, like smoke stains, maybe from burnt "anti-spatter"??
Reply:A fair amount of the brown crud is MnxOy, the various forms of manganese oxidesManganese(II) oxide, MnOManganese(II,III) oxide, Mn3O4Manganese(III) oxide, Mn2O3Manganese dioxide, (manganese(IV) oxide), MnO2Manganese(VII) oxide, Mn2O7Mn is an oxygen scavenger and part of the reason it is in there is to turn in to the oxide.  If you look at the required composition for S-6 wire, there is more Mn than anything besides Fe.   I think the boiling point is pretty low compared to the other desirable stuff in a wire, so it comes out fast and easyExperience is something you get right after you need it
Reply:Your welds look good ,the last ones look pretty hot.   Cs in the cooled weld are OK, Vs mean you are going at top speed.  Slow down a little.Straight even steady beads are good.   Aim the wire right in the joint or where the edge of the last bead meets the plate .   Smooth is good. Don't be afraid to mess with the heat, both wire speed and volts.You got it.DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:I will just add to this post, no need to make another.Took the advice your guys gave me, sped up to keep the bead size down, focused on aiming the wire at the joint, being consistent and playing around with settings.This is a T joint if 3/16" plate for the base and a 1/4" plate for the leg(?). I set the machine for 1/4" because that is what I have read to do and tried to aim the wire a little towards the thicker piece but I guess the thickness difference isn't huge so I don't know if this is really needed.Same wire, gas flow and crappy ground, though I cleaned to bare metal for the ground point and my starts were actually much crisper on quite a few of the beadsCan the crater ends be fixed by swirling the gun around at the end of the weld like I have seen done during TIG welding?Do you see any undercutting in any of there welds? I thought maybe the top edge of the bead might have been undercut a little. Hard to get a good pic of it though.Let me know what you think guys, thanks again!
Reply:To end the weld, stop travel and keep welding for a short moment.YOU should be able to see the under cut better than me.  Still a lot of spatter, maybe less stick out?Good though.DavidReal world weldin.  When I grow up I want to be a tig weldor.