floating arc

[hankj]

Thank you for all the tips, I went and bought a new liner for my gun, that helped but didn't solve the problem. I am finding tonight that when I am welding the arc comes back up into the tip and has been leaving a little ball of weld on the end of the tip I figure this is causing it to happen more frequently so when ever it happens once I check the tip it isn't always there. I have had to change my tips more tonight due to this little ball of weld at the end cause when I pick it off sometimes a little bit of the tip comes with it. Also when the wire starts to come back up to the tip it will leave some searious undercut. I am not a great welder and leave undercut at times but never like this or as much and often as this. I am getting very confused and frustrated with this as nonthing seems to be working. GOD help me tonight.

What happens if you cut back to short-arc? Hook up some C-25 or CO2, or just try it with the 6%, and see if it'll run OK in short arc. It still sounds like wire feed trouble. If I get a burnback all the way to the tip in spray with the MM210 (not nearly as robust as what you have) it's because I got too close, or I'm not feeding wire fast enough. I dunno, maybe try some .030 wire? But, .035 should spray fine with those parameters.

Hank

[Engloid]

I am finding tonight that when I am welding the arc comes back up into the tip ...

This is nearly always due to the wire feed slowing down. You need to set the tension on the rollers, tension on the spool, and ake sure you don't have excessive bends in your lead (keep it straight as possible.)

[New2theArc]

I tightened the drive rollers and that stopped the arc from floating all over the place now what I am getting is a vibrating arc. I can feel the wire vibrating through the gun before it even comes out of the tip but once I acr it is what I can only describe as a vibrating arc. I think I have the tension on too tight but when I loosen it just a bit it falls back to the floating arc. It is very confusing, my question is could this be affecting the quality of the weld (penetration) the beads still look good but that don’t' mean jack! Thank you again for all the tips

[tailshaft56]

Still sounds like the wire is encountering some kind of resistance in the liner. I would cut the wire off where it enters the liner and pull it through by hand. You may want to take off the tip first. It should pull through with minimal resistance and also feel smooth. If that's ok try it again with tip on. If thats okay check your wire spool tension. it should only be tight enough to keep the spool from freewheeling when the wire stops. One other thing is it's possible to have a poorly wound spool to cause problems. One way to check is peel off 20 to 30 feet of wire and strech it out so it can feed. You should be able to run a test bead this way.

[hankj]

At the feed speeds necessary for spray, I also can feel the reaction of the liner to the rapid wire feed, but it makes no difference to my arc pattern.

When you describe your arc as "vibrating", I have a hard time understanding what that means. Does the arc seem to climb towards the tip and then run back towards the work? If so, that is a wire feed problem! Somewhere in the balance between spool tension, drive roller tension, the gun liner, the tip adapter, and the tip, you've got a problem.

You might try another MIG gun. If you have a simpatico supplier, he might let you borrow the gun off of a demo machine?

Hank