Welder issues

[FanNumber17]

So I am not a trained welder by any means, but I have done it enough to be dangerous with basic stuff. A while back at work I volunteered to do a small welding project when another guy was out and that snowballed into me becoming the go to fabricator. I was using my personal miller 211, but we ended up getting a Miller multimatic 255 about 2 months ago. This week was the first project I had used it for and I keep on having issues with it. The arc on it seems almost erratic, starts out running alright but not great, then it will randomly start balling up on the end of the wire and act like it is going into a different transfer mode. Then go back after a second or two. As you keep welding it happens more frequently. The bead also seems to be piling up more than I think it should. I have played with the settings, using both the preset and the manual range and nothing changes. Gas is 75:25, wire is .35 70s-6. Hooked up as dcep. Is it possible some sort of setting is needs to get changed on this fancy thing? Or maybe it's just something I'm doing. Just figured I would get some other opinion

 

[Old Man Roger]

Is your wire speed consistent? It sounds like you may be binding up, slipping, or in need of a new tip? Check the tension on the feed and keep your line as straight as possible to see if it improves.

 

[zimman]

I thought there was a polarity change in those. Check that out.
Zim

 

[GaryM909]

I have had that happen with a poor ground. The surface I put the ground clamp on was clean but there was built up paint and whatever on the jaws of the ground clamp plus the spring in the clamp was weak.

 

[PWC Repair]

I had an older Century doing that, it ended up being a weak transformer.

 

[Fixr]

If it was purchased from a decent dealer, they might send someone out to check the machine and your setup under warranty. Maybe.

 

[TurnipTruck]

I have put aftermarket ground clamps on all my new Millers, and the migs also get a foam earplug or scotchbrite clothespinned to the weld wire immediately ahead of the drive roller. Name brand wire is a big factor, too. Set the drive roller tension so you can feed at 45* against a wood block without slipping.

-not a trained professional weldor-

 

[Old Man Roger]

I have put aftermarket ground clamps on all my new Millers, and the migs also get a foam earplug or scotchbrite clothespinned to the weld wire immediately ahead of the drive roller. Name brand wire is a big factor, too. Set the drive roller tension so you can feed at 45* against a wood block without slipping.

-not a trained professional weldor-

I've gotten a brand new roll that had some oxidation going on. Returned it for a new role and problem solved.

 

[kctgb]

Put your nozzle at a 45 degree angle to a welding table and hold the trigger while watching the wire curl up. It should curl up at one speed. Watch for any irregularities in wire speed. From your description I tend to think it’s a wire speed issue. If wire speed looks ok disengage the feed mechanism, put the nozzle to the side of your cheek and press the trigger. Your cheek is more sensitive than your hands to gas hitting it. Hold the trigger for a while to see if there’s any disruption in gas flow.
Miller has a welding calculator for mig welding, use their settings to see if it makes any difference. Every welder is different, no two welders weld the same. Try the calculator. You might try a bottle of Co2 if you have any, Co2 runs a little hotter than C25 and has slightly more spadder. Co2 is a lot cheaper than C25 and works just as good. Hopefully your C25 didn’t get contaminated. C25 is a gas, Co2 is a liquid. You’re good for hard wire with DCEP, flux cored is DCEN.

 

[NUTTSGT]

I have put aftermarket ground clamps on all my new Millers, and the migs also get a foam earplug or scotchbrite clothespinned to the weld wire immediately ahead of the drive roller. Name brand wire is a big factor, too. Set the drive roller tension so you can feed at 45* against a wood block without slipping.

-not a trained professional weldor-

I do something similar with a blue paper towel and clothes pin to clean the wire off before going in the rollers.


Another item to look at and verify....make sure you have the correct size roller and the wire is running in the groove.

I had an issue at one point with the latter. I swore the wire was in the groove and it wasn't. Until I got my face down there and physically looked directly at it.....not glancing at it, did I realize the issue.