Blowing holes in 20 gauge with flux - suggestions?

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Just playing/learning and and running beads to see what I can and can't do with flux-core. I have no problem with 18 gauge steel but with 20 gauge, unless I move quick leaving almost pencil thin lines, I burn holes in the metal. I'm using single sheets to practice on and not welding anything together. Welder power is on the lowest setting and wire feed is on "3" as per instructions on the door of the welder.I read* that using a copper or aluminum "chill bar" will solve it and I will get some but I'm thinking that maybe it's my newbie technique. Is there a special way to weld thin stock with flux-core? Not that I have a real need, just want to learn how. Thanks.* From Miller's site: "To dissipate heat from the weld area faster than atmospheric cooling alone, place the heat affected zone (HAZ) in contact with a "backing bar" or "chill bar." A backing bar can be as simple as a metal bar (usually copper or aluminum because they dissipate heat best) clamped to back of the weldment. This simple technique enabled one fabricator to use an all-in-one pulsed MIG power source to weld a continuous seam on .040 in. aluminum."Warning: I have been wrong before!New small workshop, small MIG, oxyacetylene set with a DHC-2000 that I'm learning to use and really like. Life is good!Typos are there for those that look for them. I try to do something for everybody.
Reply:Just get a piece of copper pipe, hammer it flat & use it a backer. Plumber left 8ft of 1in pipe here & now I have various lengths (3-15in) & different curves of backer. I even run it thru a my slip roll to match fender curves etc.
Reply:Originally Posted by ZRx61Just get a piece of copper pipe, hammer it flat & use it a backer. Plumber left 8ft of 1in pipe here & now I have various lengths (3-15in) & different curves of backer. I even run it thru a my slip roll to match fender curves etc.
Reply:Instead of using flux-core on thin sheet metal, use 0.023 solid wire and C25 gas.No flux residue to clean up, should be less spatter, cleaner welds all around, and you can do the thinner stuff easier.And to reduce warpage, etc, don't run a continous weld but instead run short beads and then stop, then run another short bead someplace else on the work and stop, then run a bead someplace else, etc.And the chill bar should help a bit too.
Reply:You can always tack weld them...tack after tack...fluxcore will have enough penetration if it 20 ga sheet.Oh but you need to clean flux after every tack? Dunno about that...Some other guy might want to answer that...of course solid wire and gas its better for thin applicationsMy Babies: HF Drill pressHF Pipe Bender3   4.5" Black and Decker angle grindersLincoln Electric PROMIG 175that´s it!
Reply:i dont know if you can with flux as effieciently, but with solid and c25 you can pulse the gun to prevent burning through. also looks very good
Reply:Well, I'm welding with flux-core, outside, and not using gas. I don't have a gas cylinder, regulator, etc. yet. So, I'm trying to see if I can do this, for kicks, with flux as it says in the table inside the welder door. Just something I'd like to figure out...with flux-core. Will try a chill bar.Warning: I have been wrong before!New small workshop, small MIG, oxyacetylene set with a DHC-2000 that I'm learning to use and really like. Life is good!Typos are there for those that look for them. I try to do something for everybody.
Reply:Originally Posted by VisorblueWell, I'm welding with flux-core, outside, and not using gas. I don't have a gas cylinder, regulator, etc. yet. So, I'm trying to see if I can do this, for kicks, with flux as it says in the table inside the welder door. Just something I'd like to figure out...with flux-core. Will try a chill bar.
Reply:Bought a piece of copper today, 2" x 6" x 3/8" and clamped in on the back of a piece of 20ga. There a lot of test welds on it already so I just did a couple of quick tests. The copper seems to have helped. Yea!Will try a fresh sheet of 20ga. later. Thanks.Warning: I have been wrong before!New small workshop, small MIG, oxyacetylene set with a DHC-2000 that I'm learning to use and really like. Life is good!Typos are there for those that look for them. I try to do something for everybody.
Reply:Originally Posted by RojodiabloAnything will work to dissipate the heat. Try a cheap piece of aluminum 1/2" thick bar. Try to use .030 fluxcore. .035 is just too thick. And concentrate on getting a puddle to form, then run from it. Point the wire in, start the arc, stay put for.... a nanosecond, then MOVE. Real steady, no jumping around. Just move along the path.
Reply:I asked the same thing a few weeks ago...  I picked up solid wire and gas for my machine and it welds sheetmetal so nicely now.But I was using .035 flux core and was constantly blowing through.  Even on the lowest settings.  The copper backing helped, but I was intending to get gas for this machine anyways.  I found that by using the copper, and short weld bursts I could get the panels welded.  But it also warped the panels.
Reply:Originally Posted by KG4ZRCBut I was using .035 flux core and was constantly blowing through.  Even on the lowest settings.  The copper backing helped, but I was intending to get gas for this machine anyways.