does AC stick provide cleaning action like AC tig?

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I've got some painted sheet steel panels I need to weld together.  They're about 22 ga (.030") and removing the paint from all the edges that need to be welded would be too time-consuming.  I got some 3/32" 6011 electrodes since those are listed as being good with dirty/painted stuff and can be run either AC or DC.My question is does running them in AC help at all with regards to the paint?  I know AC TIG provides cleaning action on aluminum, but wasn't sure if the same was true for AC stick on steel.  Of course, aluminum oxide and paint aren't exactly the same thing either...Also, would running AC help keep from blowing through on thin stuff like this?Sorry for the noob-ish questions - it's been a while since I've stick welded and that was on fairly thick, clean material.Thanks,David
Reply:Your going to evaporate 22 ga. with a 3/32 6011. I would use a 1/16 7014 and even that could be tricky if your not used to welding thin stuff with stick.Millermatic 250Lincoln 180TLincoln SP-135Miller Thunderbolt AC/DCThermal Arc 161SAirco 300 Heliwelder
Reply:Thanks for the suggestion of 7014.  I read up on it some and it said it's got a softer arc with less penetration, which might help with blow-through.  Also said it was more forgiving skill-wise which might be good since I haven't stick welded in a while. Couldn't find much about how it does with painted steel, though.  Would the softer, less penetrating arc tend not to burn away the paint as well?  These are recyled pieces of sheet that have had their edges cut with hand plasma, so there's not paint wrapping completely around the edges, but they're by no means what most would consider a weld-prepped edge.I'm wondering if a chunk of backer bar would help keep from blowing through since I have access to the back side.  I will probably pick up some 7014 and try it.  Any recommendation for AC or DC with it?Last edited by dbotos; 07-13-2012 at 01:19 PM.
Reply:What are you trying to build? Will it burn through paint? Yes. Will it lookas good as clean metal? no. If your just trying to stick it together and aren't to concerned about the way it looks just weld it as is. And a copper/brass backing bar would do wonders on the blow through. I would use DC because its is smoother, but a 7014 will run on either. Using straight polarity would cut down on penetration also.Millermatic 250Lincoln 180TLincoln SP-135Miller Thunderbolt AC/DCThermal Arc 161SAirco 300 Heliwelder
Reply:It's a mini shed for a riding lawn mower (5' W x 7' L x 4' H).  The frame is made of scrap conduit and the walls are scrap sheet metal (mix of galvanized and painted).  What's in the picture was all done with my MIG back in the spring.  The frame is fully welded, but the panels are just tacked to the frame and to each other in a bunch of spots.I had the top of a truck cap serving as a roof (painted a nice green) until it became the roof for the jungle gym.  The "door" was a painted piece of plywood with handles on it that would just lean up against the back of the mower.I needed to polish off the last of my 75/25 tank for the MIG, so last night I patched that little mouse hole on the left side and ran one 7' bead and one 4' bead where the sheet metal was touching the conduit.  Had the little Lincoln set on tap D (tried C, but that was too cold) which could blow holes in the sheet metal if you got too much heat in one spot too quickly.  Focusing the arc more on the conduit seemed to help, but still not perfect.  By the time I ran the tank down, I was wondering if stick welding would be a better process for this "dirty" welding.Last night was also the first test of my supplied air respirator system on a big project (I had previously only used it sitting down with the TIG).  It did pretty well, although I may need to upgrade to a 50' hose at some point if I work on anything much bigger.Going to pick up some 1/16" 7014 tomorrow.  Hopefully my panel mount Dinse receptacles will arrive too - the stick welder is currently apart so I can replace the fixed leads with those receptacles.  It'd also be nice if it didn't rain.  P.S.  At some point, I need to add a roof frame and roof panels to this thing.  And some hinged doors.  Will probably paint it green or light/med brown when done. Attached ImagesLast edited by dbotos; 07-13-2012 at 10:02 PM.
Reply:I've heard or read somewhere that AC helps "clean" the puddle with the pulsing alternating frequency, but I'm not sure.Seems the real issue when dealing with dirty steel is penetration, not type of current.  Although current can play a role in penetration.  DCEP is more aggressive than DCEN, and in the case of some rods AC will penetrate less than DCEP (7018AC for example).In the case of 6011 run on AC, it will do a good job of penetration, probably as good as 6010.At this point I see we've abandoned the 6011 for the sheet metal   But I thought I'd have a go at the original question.  Dunno if I'm right though"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Looking at the OP's question a little differently, the nature of the cleaning action in TIG is significant specifically because the weld puddle and right around the arc are (compared to stick) clean and shielded by gas. The area around a stick welding arc is essentially a molten salad dressing like mix of weld bead (when we do it right) and slag. I would expect that the slag that forms on the weld will prevent such action or slow it down enough to be less effective, in the same way that it prevents wind (atmosphere) or other contaminants from acting on the weld bead as it cools. Ironically leading into the benefits of stick. Namely being less affected by things like wind, rust, paint, dust, etc. I don't often see a TIG welder mounted on the back of a tractor on a 3 point hitch being run off PTO in a corn field. Just a disclaimer about my contaminants comment. I said "less affected" and not "unaffected" to be clear. Just to prevent anyone from thinking I am saying stick welding is magic and to throw away grinders! I evoke Article 6P. Proper Prep Prevent P|$$ Poor Performance.
Reply:Originally Posted by dbotos I know AC TIG provides cleaning action on aluminum, but wasn't sure if the same was true for AC stick on steel.
Reply:So it sounds like TIG and stick are opposite when it comes to which DC polarity provides more penetration.  Learn something new every day.  I went out today and got some 1/16" 7014 rods.  I also have some 1/16" 6013 rods that I got back when I bought the machine just to test it out with.  So I guess I can try both of those on DC-.My Dinse receptacles and plugs arrived today as hoped.  Got the front panel modified for the receptacles and will be reassembling tomorrow:http://weldingweb.com/vbb/showthread.php?t=141101
Reply:I would not attempt to weld 22g sheet metal with any stick. Too thin of material.Thats where mig is nice.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:I got the tombstone back together today (see other thread) and took it out tonight to try welding this sheet metal.  It was certainly no magic bullet, but I was able do a pattern of tack-cool-tack-cool... until I had a closed joint.  The 7014 and 6013 seemed to do about equally with that task on DC- at 35 amps.  Then, once there was more metal there from all the tacking, I could go back and weave a "cap" over top of it without it burning through.  The 7014 seemed better for that.  It's ugly, but they're welded together (it's either an ugly butt weld or a butt ugly weld).  I got a couple feet worth done tonight.I may get one of these little spot blasters and see how long it takes to prep so many feet of joint:http://www.tractorsupply.com/clarke-...ng-kit-3907853I've been looking for an excuse to buy one and this seems like the perfect one.  If it does alright, I'll have to go back and try the MIG again...
Reply:1) Welding 22ga with stick is nearly impossible. Your options are MIG or TIG, pretty much.2) Break out your angle grinder with a sanding disc, and get to work removing that paint. That fact that it's annoying and time consuming isn't an excuse.  Take some pride in your work and don't cut corners.Another option is to use a propane torch and burn the paint off, then sand/buff off the oxidized residue. Do the burning outdoors.The only reason you should weld through paint is if it's an emergency repair, or if there's no realistic way to reach it with a grinder.Technically speaking, the cleaning action with AC TIG comes from the electrode positive part of the cycle. That means electrons travel from the work to the electrode. The positive charged gas ions bombard "cathode spots" on the work surface and cause local vaporization/etching.Stick welding DC normally uses electrode positive all the time. DC TIG on the the other hand, uses electrode negative.However since stick welding doesn't use a non-reactive shield gas like argon, it depends more on the flux in terms of cleaning action. In other words, there's enough oxygen present in the weld zone that the arc wouldn't provide sufficient cleaning by itself.
Reply:I picked up one of those spot blasters yesterday at Tractor Supply and tried it out last night.  It did a nice job of prepping the joint by making overlapped spots of cleanly blasted metal.  Fairly time-efficient too.  Not as dust-tight as a cabinet, but certainly a lot better than just using a siphon gun or pressure pot out in the open (I just had on normal safety goggles and a respirator while using it and was fine).  Next time, I'm going to set up a box fan pointing parallel to the surface I'm working on so it just blows away any fine dust as I work instead of it getting on my hands/forearms and the panels.Anyway, having the joints clean allowed me to turn the MIG down a good bit more and weld on a lower setting with that.  The "beads" were still no beauty contest winners, but they were better than the stick and I could lay 'em down faster with the MIG.So, the takeaway is it's possible to weld thin stuff  with stick, but it will most likely be slow and potentially ugly.  Having clean metal helped with the MIG so that it didn't have to be turned up so high to burn the paint off (plus it wasn't contaminating the weld).  The spot blaster was definitely worth the $10 I paid for it and I will certainly be using it more in the future (it also comes with inside corner, outside corner, and sheet edge tips).  AC stick doesn't seem to share the same cleaning action as AC TIG due to the nature of stick welding using a flux-coated consumable electrode.  I also got (re)educated on various stick welding rods, which should help on future stick-welded projects.  Thanks again for everyone's input!