Mig Welder Acting Strange?

[racer8432955]

My 30 year old cheapo Century Welder suddenly is acting weird. While I am no professional it was always a decent machine for doing light gauge stuff, and I could get an acceptable weld. Using the same .125 thk. material, mill scale sanded off, I can get good results with my trusty Miller but the little guy doesn't seem to work anymore. It makes sort of a flaming noise, and unstable arc, and seems like its doing that thing tig welders do on aluminum (balance / cleaning effect?). Again, it worked well for years, but recently started doing this. I'm using the same 75/25 gas that I use in Miller. Is this an obvious, "the machine wore out this, and now its junk" situation? I wouldn't be heartbroken if so, its old, was cheap and served its purpose for years.
Any ideas?

 

[MP&C]

You may need a new liner. I always look for pinch points. Where the stinger lead should come out straight from the machine (in most cases) yours looks to drop immediately from the front panel. Right in that area is likely to have wear in the liner, which will indeed affect machine performance.

 

[strength_and_power]

When is the last time you replaced the contact tip?

 

[welder4956]

You might try blowing the liner out with compressed air before replacing it. The liner can get filled with dust and particles rubbed off the wire, especially if there is a little surface corrosion on the wire from not being used frequently. You can also get a wiper that slides onto the wire before the drive roll to help keep it clean. One of these: https://www.amazon.com/Weld-Aid-Lube-Matic-Wire-Kleener-Pack/dp/B008RA5D5C?tag=atomicindus08-20

 

[MoonRise]

Check contact tip, drive roll, drive tension, liner (blow out or replace), check all the torch to machine connections (both electrical and the gas seal o-rings).

Small 4" diameter wire rolls ( 2 lb solid wire) can get iffy feeding when they are getting to the end but not all used up too.

Have you cleaned the crud from the ID of the gas nozzle?

Go through one by one everything in the wire feed path and verify that they are all properly set and adjusted.

 

[NUTTSGT]

Is the wire in the groove of the drive rollers ?

I use a piece of blue paper towel with a wood clothes pin to wipe the wire before it goes into the drive rollers.

 

[racer8432955]

When is the last time you replaced the contact tip?

its been a while. thanks for the suggestion. i'll have to check / try that

 

[racer8432955]

Check contact tip, drive roll, drive tension, liner (blow out or replace), check all the torch to machine connections (both electrical and the gas seal o-rings).

Small 4" diameter wire rolls ( 2 lb solid wire) can get iffy feeding when they are getting to the end but not all used up too.

Have you cleaned the crud from the ID of the gas nozzle?

Go through one by one everything in the wire feed path and verify that they are all properly set and adjusted.

great suggestions. I have to admit I've done little (no) maintenance on this thing.

 

[BigMike782]

While doing maintenance on the Century don't forget the Millermatic 200.
It can use having the wrapper taken off and blown out with compressed air and then check the range plug nuts(back side of the receptacle) for being tight. They have a tendency to loosen with heating and cooling cycles and can get to the point the plastic melts and you really don't want to replace those.

 

[rooster59]

Everything above, great info. Also, check your gas hose for leaks, also flow meter should be rock steady.

 

[Chris F]

In addition to all the above, make sure the ground clamp connections are still good.