Pops when welding

[steve moore]

I recently bought a nearly new Lincoln Handy Mig I've never mig welded before. Started practicing with flux core and it worked OK. Now I've upgraded to gas Got a cyl with c25 mix from craigslist and a new regulator It will lay down a descent bead, but the arc pops intermittently and I can hear the wire drive motor strain for a second when this happens you can also hear the hum of the machine get louder like it's straining. Wire drive motor seems to strain and slow down when I tested it with hose stretched out straight. Could it be the sleeve that the wire feeds through? Like I said it's nearly new. Could something have damaged it? Shouldn't the drive motor have a steady speed when I push trigger?

 

[J.B. Welding]

Hi, does the roll of wire turn freely at all times, it could be catching somewhere or need lubricant. Also yes the liner could need replacing.. It sounds like the wire is being strained before the feed motor though with the noises you report.

 

[BrokenBiker]

sounds like the reel is dragging on something casuing the motor to struggle. if the problem was after the motor, the motor will keep throwing wire out anyway and it would just birdsnest inside the unit

 

[steve moore]

sounds like the reel is dragging on something casuing the motor to struggle. if the problem was after the motor, the motor will keep throwing wire out anyway and it would just birdsnest inside the unit

 

[steve moore]

Maybe I'm just being too picky the welds it makes look great, it's just more annoying than anything. I hope it doesn't damage my machine. The spool of wire has a built in tensioner (not adjustible) so it does always have a drag on it. I did spray some dry lube on the spindle. I have no idea about the quality of the gas I've got. I bought a used cyl already filled. It's got an official looking sticker that says 75% argon 25% co2. Can the gas get contaminated or old? I have no idea how old it is or where it came from.

 

[Jan]

I would first suspect that the non adjustable tensioner on the drum spindle is dragging too much. After that I would check the amount of compression at the drive rollers and/or any wobble on the pressure roller as it's compressed against the powered roller. The Lincoln's aren't usually associated with this problem, but it only takes a moment to confirm or deny this is happening. Even as 'nearly new' the liner could be worn out and, for the minimal cost of £4 (US$5-6)or so, is well worth the investment. Don't forget that there's another, much shorter, liner inside the swan neck of the torch which may need replacing at the same time.
If all is well so far then turn your attention to all the electrical connections inside the machine. Pull off all the push-fit connectors - ONE AT A TIME! - and remake them with a coating of either electrically conductive grease or petroleum jelly. This action will cut through any high resistance corrosion while simultaneously coating them to prevent more moisture or air getting to them for a while.