roping

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Just a question.  When using my MM 251 with 75/25 mixed gas (CO2 argon) I seem to get a lot of roping, or high amount of weld bead, when laying down a weld on a flat surface.  Without changing gas, is there a way I can flatten it out a bit?  I played with the voltage and wire speed settings, but didn't see much of a difference.Thanks in advance.The Lord has declared, "This is my work and my glory--to bring to pass the immortality and eternal life of man"  Moses 1:39Link: My name is John, and I am a member of The Church of Jesus Christ of Latter-Day Saints.-- ColdCreekWorks.com --
Reply:If you say you are welding on a flat plate that has no groove, then your weld bead has no where to go.
Reply:Increasing the voltage will flatten the bead.Push vs pull will give a flatter bead profile.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Originally Posted by Jay OIf you say you are welding on a flat plate that has no groove, then your weld bead has no where to go.
Reply:Originally Posted by SundownIIIIncreasing the voltage will flatten the bead.Push vs pull will give a flatter bead profile.
Reply:A few examples . . . . Attached ImagesThe Lord has declared, "This is my work and my glory--to bring to pass the immortality and eternal life of man"  Moses 1:39Link: My name is John, and I am a member of The Church of Jesus Christ of Latter-Day Saints.-- ColdCreekWorks.com --
Reply:Thats about normal from my experiance. Hard to tell from the pics but did you grind all the mill scale off? Short circuit mig is notorious for just sitting on top on mill scale and cold lapping. I think I might spy a little bit of it in the toes the weld in the third pic.  It's really hard to tell sometimes though. Unfortunately, we are required to weld through some light to medium mill scale at work with -6 wire. The only way I've figured out how to tell is by watching the molten trailing part of the puddle while welding or just after welding to see how and where the heat is dissapating. hard to explain in words...not that words are my strength to begin with. Of course by that time its too late lol. I beg the bosses for dual shield at least once a week haha.I find that pushing the weld and bumping the volts up a few tenths from normal helps to preheat ahead of the weld and spread out the heat of the arc into the toes of the weld promoting better fusion. Of course thats at the expense of penetration and fusion to the root if you go to slow or to cold.... Long story short mill scale is a dirty sob.Last edited by i4sillypwr; 04-02-2010 at 12:40 AM.
Reply:Originally Posted by jdh239Just a question.  When using my MM 251 with 75/25 mixed gas (CO2 argon) I seem to get a lot of roping, or high amount of weld bead, when laying down a weld on a flat surface.  Without changing gas, is there a way I can flatten it out a bit?  I played with the voltage and wire speed settings, but didn't see much of a difference.Thanks in advance.
Reply:Originally Posted by i4sillypwrThats about normal from my experiance. Hard to tell from the pics but did you grind all the mill scale off? Short circuit mig is notorious for just sitting on top on mill scale and cold lapping. I think I might spy a little bit of it in the toes the weld in the third pic.  It's really hard to tell sometimes though. Unfortunately, we are required to weld through some light to medium mill scale at work with -6 wire. The only way I've figured out how to tell is by watching the molten trailing part of the puddle while welding or just after welding to see how and where the heat is dissapating. hard to explain in words...not that words are my strength to begin with. Of course by that time its too late lol. I beg the bosses for dual shield at least once a week haha.I find that pushing the weld and bumping the volts up a few tenths from normal helps to preheat ahead of the weld and spread out the heat of the arc into the toes of the weld promoting better fusion. Of course thats at the expense of penetration and fusion to the root if you go to slow or to cold.... Long story short mill scale is a dirty sob.
Reply:Originally Posted by RhynoRemember that "A weld is like a woman.....if you get her hot, she will lay down. If you do something to cool her down, she'll stand up."-Rhyno
Reply:Originally Posted by RhynoRemember that "A weld is like a woman.....if you get her hot, she will lay down. If you do something to cool her down, she'll stand up."-Rhyno
Reply:Originally Posted by RhynoRemember that "A weld is like a woman.....if you get her hot, she will lay down. If you do something to cool her down, she'll stand up."-Rhyno
Reply:When that analogy was told to me, not only did I laugh, but it also helped me with my welding.  With the MIG process, there are a number of things that can be done, to control the heat.  I.E. More voltage, or less wire speed, or different stick out lengths, gun angle or direction, travel speed, etc."Either way, get her hot, and she'll lay down."-Rhyno07 Fowler 200D65 RedFace04 Miller TB 302, 22hpMiller 12RCMiller HF 251-1Lincoln SP135HyperTherm PM 380and a few others... Originally Posted by RhynoBut, if I "all of a sudden disappear....  ...." hopefully I didn't suffer too much....