MIG Bead question

admin

I've had my MIG for about 6 months now and finally seem to be getting some results.However, from time to time, I have the hardest time running a bead. It seems like that the wire is just melting and dripping blobs on the metal and not welding. There is no 'bacon frying pan' noise and the weld just doesn't seem to want to move. I run 7-10 (whatever the units are) on Argon/CO2, 35 wire size and this usually happens on 16 guage material.I may show up the next day, now touch a thing and BINGO, perfect MIG welds.Any help appreciated-
Reply:Do you have wire tip too far away from metal? That can cause it as well as not a fast enough wirespeed.
Reply:Sounds like the wire feed is hanging up on you.
Reply:You may also want to run a little more gas. You may want to try .025 wire as well and I think you'll have much better luck all around. .035 is big for 16ga, its certainly doable, but I've always done better on 16ga with the thinner wire.And make sure your metal is clean.
Reply:What machine?  If this is a 120V unit, .035 solid wire is too big for good, consistant results.  It doesn't have the voltage needed for it.I, too, would recommend more gas.  I stay between 12 and 15 when there is no chance of a draft, and go to 20 when circumstances require it.  These numbers are cubic feet per hour (CFH.)Wagons made a good point also; make sure the steel is clean for the GMAW process.  No rust, dirt, or oily stuff.
Reply:If you're on a consistant diet of the 16 gauge or around that, you might be just outside the most desirable range for the .035 as stated by others. Sure with experience you can always do itty bitty stuff with fat wire and fat stuff with itty bitty wire, but each one has it's range that it performs best in. That's why they make several sizes. For me 16 gauge would be right in a transition zone where it would be a toss up between .025 and .030... Would depend on what was already on the machine.  Lot of the time I like to run at the upper end of a wire just so those starts aren't quite so critical so I tend to run smaller wires but that can create it's own set of problems.Few things to watch for, most have been mentioned already:Run a wire better suited to the metal thickness.Make sure you have good clean metal.Get in the habit of looking for a melted ball or nub on the end of the wire. Clip it off.
Reply:Add to what sandy said :  keep the cup (nozzle) clean . don't let  it fill up with dingle berries . Some nozzle spray helps .
Reply:Another thing that I occasionally run into is the gas going stale inside the hose.  Since I don't weld every day (or even every week), I have to purge the argon in my tig hoses by hitting the foot pedal once or twice while maxing out the postflow.  If I don't, I experience a problem similar to what you describe.I know that you're talking about MIG, but the problem could be similar if you have a lot of hose between your tank and the gun.