Having problems with co2

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I have a Century 155 amp wire welder. I have been welding with it for about 6 years using flux core or 75%25% mix gas depending on what I was doing. This little welder has been great. Over last year or so I have only used mixed gas with great results. The other day I was replacing some angle iron pieces on a snowmobile trailer and ran out of gas. Looking at how many welds I had in front of me and not wanting to chip slag from all the corners of the angle I had the LWS swap me a tank of co2 because he said it would last much longer than the mix gas.I had a nothing but trouble trying to get it to weld. It pops and snaps like the wire is too fast or a bad ground. I cleaned my ground location and I tried turning the wire way down and still pops and "bucks" and I tried turning the heat way up with simular results. With the heat way up it will lay a bead but your riding the "bucking" gun and really having to work. When I tried to go vertical up there was no way and I didn't even try overhead. This is the same spool of solid wire I was useing with the mix gas so I don't think its bad. I swaped out the wire for flux core and changed polarity and she welded like a dream again.Is there some tricks or special wire to use CO2 compaired to mix gas and flux core?Off hand I do not know what wire I use. It is from my LWS general purpose solid .30 or .35 Linclon Innershield flux coreThanksMundyLast edited by Mundy; 01-04-2010 at 09:56 AM.Regards,Mundy
Reply:co2 is going to spatter more than 75/25 mix. it burns hotter so you can forget the settings you would use with 75/25 mix. turn your heat down from what you are used to and you have got to stay in the center of the puddle. if you stray out while in forward motion it will pop bad until you get back to the center of the puddle and stabilize the arc. work the puddle a little slower than you have been with the mix or fluxcore. it does take some getting use to. co2 does last longer than the 75/25 mix for sure. Randy
Reply:My Miller Mig manual goes into the different gasses and there welding properties. CO2 is very spatter, Miller suggests increasing the inductance by taking a few turns of the ground cable around a chunk of iron. The added inductance changes the short circuit-arc on time to more arc on and cuts down on the spatter. Before and after photos show a marked difference in the bead.
Reply:Thanks for the replies, I will try the coil of the ground wire and I have to work on technique with the co2. I am amazed that it is so differn't. I never saw much differnce in tecnique between flux core and mix gas other than slag and spatter.Regards,Mundy
Reply:You might also check to make sure your ground is good. Mig requires a solid ground. I use nothing but CO2 and have none of those problems and just slightly more spatter than with mix gas.
Reply:All Gas Shielded Flux Cored wire, is made with co2 as the gas.( in the lab )  JGSMAW,GMAW,FCAW,GTAW,SAW,PAC/PAW/OFCand Shielding Gases.  There all here. :
Reply:Originally Posted by Mundy With the heat way up it will lay a bead but your riding the "bucking" gun and really having to work.
Reply:I did not say you had to.  Thats the way they are formulated in the lab.  Better Mechanicals, Physicals, spatter and ETC with c-25.  Watch what is written, don't guess.  JGLast edited by weldgault; 01-04-2010 at 11:30 PM.Reason: left out a wordSMAW,GMAW,FCAW,GTAW,SAW,PAC/PAW/OFCand Shielding Gases.  There all here. :
Reply:sn0border88,                   I'll try that and see how it works, when I swapped over to co2 from mix my supplier advised less voltage for the co2, seemed to work for me and my guys. [I]'ll also try wrapping the ground around a steel bar to see if it helps with spatter. Randy
Reply:Co2 doesn't last longerEd Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:Originally Posted by transitMiller suggests increasing the inductance by taking a few turns of the ground cable around a chunk of iron. The added inductance changes the short circuit-arc on time to more arc on and cuts down on the spatter.
Reply:For the same WFS using the same solid wire, there is a 1-2 volt difference between the voltage used for C25 versus plain CO2.The CO2 uses the higher voltage.Your description of the 'bucking gun' is describing "stubbing", where the WFS is too high for the voltage or the voltage is too low for the WFS and the wire is physically pushing into the workpiece and pushing the gun back instead of the nice smooth MIG short-arc sizzle happening.example:  Lincoln says a WFS of 150 ipm at 18 volts is 70 amps using 0.030 L-56 solid wire (ER70S-6) using plain CO2.  If using C25, the voltage needs to be dropped 1-2 volts.  Example:  Lincoln SP175Plus 0.030 L-56 wire, 12 gauge workpiece  Recommended setting with CO2 is H-9, with C25 it's G-9.  Using 0.025 L-56 wire on 14 gauge workpiece, recommended setting with CO2 is G-6.5 and with C25 it's D-6.5.  etc, etc, etcAnd Ed/Broccoli is correct but cryptic in 'CO2 doesn't last longer'.  At 20 cfh flow rate, 80 ft3 of gas will last for 4 hours of arc time no matter what the gas.  It's just that a physically 'small' tank of liquid CO2 has a LOT of gas volume contained in that liquid once it expands to a gas (something like a 20 lb tank of liquid CO2 is around 200-300 ft3 (?)  of gaseous CO2 once it expands from liquid to gas.)  Also be aware and/or careful of regulator freeze-up if using plain CO2 in a regulator made for C25 or other gases.  The best laid schemes ... Gang oft agley ...
Reply:Originally Posted by d94joncavery interesting - gonna have to try that. now, forgive me if this is stupid but does it matter if its wound cw or ccw? i guess my question is does the inductance of two coils placed in serial still add up if they are wound in opposite directions?
Reply:if you do have the time it would indeed be interesting to see a photo of the difference whenever you get ahold of your camera. as for the cw/ccw issue you are saying to look at the existing coil inside the welder and make sure to wind the improvised external coil in the same direction, in order to get an additative effect rather than a cancelation?i only weld for a hobby, and i use co2 exclusively. i dont think the spatter is too bad but less would certainly be nice.
Reply:Originally Posted by d94joncaif you do have the time it would indeed be interesting to see a photo of the difference whenever you get ahold of your camera. as for the cw/ccw issue you are saying to look at the existing coil inside the welder and make sure to wind the improvised external coil in the same direction, in order to get an additative effect rather than a cancelation?i only weld for a hobby, and i use co2 exclusively. i dont think the spatter is too bad but less would certainly be nice.
Reply:Originally Posted by transitNo, the inductor in the power supply is independent of anything you add externally because they are wound on independent cores.
Reply:Yer going to need a Longer Work cable once you warp it around the SteelThis isn't mine, Pic belongs to DanEd Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:Originally Posted by MoonRiseAnd Ed/Broccoli is correct but cryptic in 'CO2 doesn't last longer'.  At 20 cfh flow rate, 80 ft3 of gas will last for 4 hours of arc time no matter what the gas.  It's just that a physically 'small' tank of liquid CO2 has a LOT of gas volume contained in that liquid once it expands to a gas (something like a 20 lb tank of liquid CO2 is around 200-300 ft3 (?)  of gaseous CO2 once it expands from liquid to gas.)  Also be aware and/or careful of regulator freeze-up if using plain CO2 in a regulator made for C25 or other gases.
Reply:If you have access to an iron doughnut for the core that would be more efficient than a solenoid wound coil.
Reply:Originally Posted by weldgaultI did not say you had to.  Thats the way they are formulated in the lab.  Better Mechanicals, Physicals, spatter and ETC with c-25.  Watch what is written, don't guess.  JG
Reply:Snoborder is right about gas types used with dual shield fluxcore wires.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Originally Posted by sn0border88Your going to have to explain yourself better, because neither of your posts make any sense to me.  Some gas shielded wires are meant for only 100%CO2, some are meant for only C-25, and some are acceptable to run with either.
Reply:...Well...'Mundy'.....where are you getting .030-.035 solid flux-core innershield? you're talking 2-3 different things here....  I've spent years MIG welding with .035" solid wire, C02 gas....wire + or 'reverse'......built many, many tons of stuff....a little more spatter than 75/25....but no problem going up-down-sideways...or that-a-ways....  Pressure vessels..... 1/4"-3/8" A36 rolled into 6-7 diameter foot tubes, 10 feet long....take 2 of them...make 20 foot long tanks......full-pen... Inspector certified all welds...1/4" plate...about 3/32" gap...weld v-up one sidfe....grind the other side a little...weld it v-up....it's done....use some anti-spatter spray....3/8" plate.....about the same, two passes v-up on each side.... Sounds like you're running the wire too fast if it's 'stubbing', or you need more voltage....Dougspair
Reply:Originally Posted by weldgaultAfter 20 years of working for Linde, Hobart and TRi-Mark and selling wires.   I was trying to give you some information about the way Gas Shielded Wires were made. They are not called Dual Shield, that is a brand name by Alloy Rods ( Now Esab ). If you want to know more, go to the books.  JG
Reply:Kleen-x tissue is a trade name for paper tissues. But not all paper tissues are Kleen-x.When you have a runny nose what do you reach for, Kleen-x or a tissue?Last edited by transit; 01-06-2010 at 07:57 PM.dougspair, I can see how it would be read that way but thats not it. I have used 2 wires, one is general purpose solid .30 and the other is .35 Innershield flux core. Thank you all for the input. I have done some additional searching and reading during this thread and I think I understand what is going on more. I also tried the co2 again last night. I was able to find "sweet spots" of adjustment balencing the voltage and wire speed but it took very fine adjustment and I found just how I held the gun could change the wire speed enough to get me out of that sweet spot. With the frequency that I weld (once or twice a month) I am going to just switch back to mix gas and be done with it. Thanks AllRegards,Mundy
Reply:You may have found a sweet spot to run the puddle. However CO2 is not an inactive gas, the oxygen will react with the aluminum to form aluminum oxide and contaminate the joint, meaning weak and brittle. The inventers of the mig process choose inert, none reactive gas for a reason and to do otherwise is foolish.
Reply:Originally Posted by transitYou may have found a sweet spot to run the puddle. However CO2 is not an inactive gas, the oxygen will react with the aluminum to form aluminum oxide and contaminate the joint, meaning weak and brittle. The inventers of the mig process choose inert, none reactive gas for a reason and to do otherwise is foolish.
Reply:OPPS!! got him mixed up with someone else.