Technical Pop Pop Buzz (Welding Question)

I’ve got a welding question that I can’t find an answer to.

I have a fairly nice 5-6 year old Miller mig welder that I’ve had for a few years and have used it quite a bit. Lately when starting a weld on butt joints (thin metal patch) the weld will pop several times before settling down to a buzz. If I continue to place small welds along the joint, each subsequent weld is fine with no pop. It is only the first one...irritating. Also, if I wait to let the metal cool and start again, the first one will pop. Sometimes the pop will fry the wire to the tip but usually it just pops several times.
I’ve tried more heat, less heat, more speed and less speed. Also, my grounds are good as far as I know.

I have the Millermatic DVI with 6 heat settings and infinite variable wire speed It is connected to 240v. I use Argon/Carbon Dioxide gas.

Any help or tips is appreciated.

 

Have you checked the O-rings at the base of the gun, where it connects to the machine? Might have a gas leak there. Also, how old is your bottle of shielding gas? If it has been setting idle for a decent amount of time, sometimes the gasses seperate and can cause problems too. I'd check the O-ring's first,though.

 

Is your wire smothh?, Meaning no rust?

 

. My gas is a month old. The problem pre-dates it. I will check the orings but if I forget to turn on the gas, my welds are horrid and not smooth, so I know there’s enough at the tip. Seems to me to be an electrical issue...just not sure

 

Yes, no rust. Feed seems smooth.

 

Are you clipping the little molten ball off the wire each time? Also as metal heats up it tends to weld better, could just be the "cold" starts. Make sure the metal you are welding is really clean. Rust, dirt or any kind of debris will also make it pop. My Hobart mig does the same thing.

 

It doesn’t seem to matter whether the wire has a ball or not. I usually start with a clean cut of the wire.

 

I would revisit the ground......I know you said it was good, but there is this thing called the grounding imp....Little bastard specializes in messing with your grounding point the second you drop yer hood and attempt to strike......everybody that's ever burned rod or wire will agree ,I'm sure

 

Sounds like the gas is not reaching the tip fast enough. Once you get enough it works well. Maybe a restriction ???

 

My guess is a wire feed problem. Not feeding consistently when you first start. Change tip, check tension on wire feed roller. When you first start up in the day, pull the trigger and see if it feeds wire smoothly against an ungrounded piece of steel. Might be out of spec wire.

 

Make sure your nozzle is clean, run the wire with gas on a for a few inches, snip it off and try again.

While you have the nozzle off, change the tip too.

 

take apart the ground wire and clamp connection clean it it can be arcing in the clamp and only realy conducting after the first hit ..
fabricator john
miss you dad

 

Just as @pkhammer says try by cutting the ball off the end of the wire. This is actually the proper technique before you start a bead.

If that does not solve the problem then start checking the ground and connections.
The first I was taught by my father and confirmed when I went to Modern Welding School eliminate the simple before jumping to the complex when trouble shooting a welder.

 

Check the ground cable to clamp and from to machine. also Hot check the cable to the whip mounting lug (where the o rings are) and clean out the liner.
Probably wouldn’t hurt to take the cover off and blow it out too.

 

I still suspect it is your wire cheap Chinese wire will cause trouble t can be soft with hard spots at random
You are using .023 right? Put in a new contact tip with a new roll of quality wire and try that.

 

I had a similar problem quite a while ago. I found I could beat it by by setting the amperage & wire speed to zero, turning on the gas and pushing the weld button, with my ear near the tip of the gun, until I heard gas escaping. Then I'd adjust the settings & start the weld with no problem. Been doing that for years.

I might add I have the habit of shutting off the tank, purging the line and then closing the gas adjustment. It takes a few seconds for the gas to reach the nozzle after the purge.

 

Adjust the tension on the spool. Might be some slack, then jerks during wire take up as it passes thru the rollers.

 

I’m going to check my ground for continuity. I’m thinking it is indeed a feed issue. It only pops sometimes so maybe the sheath is binding depending on the angle and twist of the nozzle. I’m going to try cleaning it out and maybe it needs replacing.

Thanks everyone for the input.

 

So I figured out I had at least two problems. My spool resistance was too high. There’s only supposed to be a slight resistance on an 8 inch spool and I had a lot. Also, the drive wheel pressure was set too low and I think it was slipping. I increased it. I also blew out the sheath and got a little debris. Seems fine now.

 

Thanks for posting your corrective measures. Good to know.

 

ground first then check to be sure the wire is located in the roller correctly stumped me for a while also turn the wire speed down and run the wire untill you hear the gas coming out the adjust wire to what you want