Dual Shield

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For the past 2 weeks I've been welding on some structural components. We're running .045 dual shield with 75/25 for gas. I was set at 28 volts and 600 on an old hobart wire feeder. I was averaging about 8.5 lbs of wire per hour. Things are getting so hot that I had to wrap the gun in corrugated cardboard because it was cooking my hands. I miss water cooled guns that I have used in the past. I thought I took more pictures, so I'll have to upload the whole beam pictures tomorrow.Oh.. And no, there is no undercut in that photo. I still had another 4 cover passes to do. Attached ImagesCommon sense in an uncommon degree is what the world calls wisdom.
Reply:Looks good, I love dual shield. We use it with 100% CO2,
Reply:I use it with 100% co2 too. c25 costs 6.5 times as much around here, not counting having to go get it.Dynasty 200DXPassport plus w/ spoolmate 100victor 315c oxy/(act and prop)Miller digital elitemilwaukee power tools
Reply:why the 0.045"?   i have one machine setup for 0.052 and find that gets way less use than the machine set up for 1/16"Vantage 500's LN-25's, VI-400's, cobramatics, Miller migs, synch 350 LX, Powcon inverters, XMT's, 250 Ton Acurrpress 12' brake, 1/4" 10' Atlantic shear,Koikie plasma table W/ esab plasmas. marvel & hyd-mech saws, pirrana & metal muncher punches.
Reply:Great stuff, for what it does well.  You can do beautiful verts with a bit of practice.Full UT.
Reply:Nice work. Lots of spatter though.In your shoes I'd suggest your manager to switch to .045 solid wire. For horizontal /flat fillets on thick plate, spray transfer is generally the most cost effective option. Much less spatter and less labor wasted chipping slag and grinding off spatter.  Another cost saving option is to use 1/16" dual shield wires for flat and horizontal fillets. You can get modestly better deposition rate and thicker wire's a lot cheaper.At my company we use dual shield for vertical, horizontal butt, and overhead welds. Flat is for spray transfer.The cost of gas is almost always less than both the cost of wire and the cost of labor.General flow setting is about 35 cu. ft. /hr. But on-arc time is usually around 20-30%. So you're looking at buying  6-9 cu ft of gas for an hour of labor.  If you can reduce the amount of time grinding off spatter it's worth it in most cases.If you keep in mind that about 25% of dual shield wire ends up on the floor as slag. So it's closer to about 6 lbs of weld per hour. With similar settings on spray transfer you can easily exceed 11 lbs per hour, and that saves a lot of gas on a per-pound-of-weld basis.Last edited by Joshfromsaltlake; 08-30-2012 at 06:06 AM.
Reply:Some 'dual-shield' wires are rated/made for use with plain CO2 only and some are for mixed gas only (C25, etc) and some can be used with either (plain CO2 or mixed argon-CO2).  So RTFM.  Hmmm, unknown exact wire but ~28V and ~600ipm WFS seems to be in the neighborhood of ~300 amps or so.  Yeah, that's getting up there with the heat.But as mentioned, although FCAW-G certainly has its place, GMAW in spray transfer does as well.  And flat indoor welds like you are doing might be 'better' served with some solid-wire spray transfer.FCAW-G can run about 85-88% transfer efficiency (so ~12-15% of the wire weight is 'lost' as slag and spatter).  You say you are running through ~8 lbs of wire per hour.  Certainly 'respectable' as far as transfer efficiency and amount of metal being put down.But  running some 0.045 solid wire in spray transfer and you should be up into the high 90's% in transfer efficiency and could be putting down around 12 lbs of metal per hour around that same 300amp power level.Run some metal-core wire around that 300 amp mark and you could be around 15 lbs/hr  of metal getting deposited.  (Lincoln MC-706 E70C-6M H4 0.045 with C10 gas at ~600 ipm WFS and 25-30V gives ~325 amps and ~15 lbs/hr metal deposited at a listed 98% transfer efficiency.  Run C25 gas and you bump up the voltage 1-2 V above that.).  YMMV depending on the exact parameters being used.But if the 'spec' said to use a certain wire/class, then you use that certain wire/class.  The best laid schemes ... Gang oft agley ...
Reply:It's too bad you can't switch to a #5 gun and run 3/32" FCAW-G. I run a pile of it at work and after I got over the fact that the stuff is intimidating because it's huge it's an awesome alternative to running multiple pass 1/2" fillets. But, it does get pretty warm.
Reply:I ended up selling him on spray transfer.. He was reluctant to do it in the beginning, but when I threw some numbers at him after weighing my spool, he caved in. And just as I thought, it's a lot faster. I'm still running at 28v and around 500 ipm, but still going through 8.5lbs an hour. In the beginning, the guys were doing one weldment in 9 hours and with me running spray now, I can get it done in a little over 3. And I thought my gun was hot before.. I dont have any new pictures of the spray. I'll upload them in a few days. Attached ImagesCommon sense in an uncommon degree is what the world calls wisdom.
Reply:What about buying a atercooled mig gun? Make money by increasing deposition rate and productivity.Welding/Fab Pics: www.UtahWeld.com
Reply:You could also get a longer goose neck for that type gun to put your hand farther back from the heat. Thats if you can't get them to upgrade to a watercooled gun.
Reply:YEah, if you have a watercooler, no reason not to have a water cooled mig gun. I always wanted one for the cool factor. No pun intended. I have only gotten my gun really warm about 3 times. I was using a magnum 400 gun on a 250amp machine. How anyone can weld above that on a regular basis is beyond me. The front of my gloves were smokin.Lincoln Power Mig 210MP MIGLincoln Power Mig 350MP - MIG and Push-PullLincoln TIG 300-300Lincoln Hobby-Weld 110v  Thanks JLAMESCK TIG TORCH, gas diffuser, pyrex cupThermal Dynamics Cutmaster 101My brain
Reply:Maybe one of these?"Where's Stick man????????" - 7A749"SHHHHHH!! I sent him over to snag that MIC-4 while tbone wasn't looking!" - duaneb55"I have bought a few of Tbone's things unlike Stick-Man who helps himself" - TozziWelding"Stick-man"