Junk Lincoln 140 C ??

[jjeff]

So I have a Lincoln 140 c has infinite amp and wire speed adjustment about 10 yrs old. Never worked correctly like my old Lincoln 100 or 125 amp with infinite settings. Tried big and small rolls of various brands mig/ and flux core wire, currently have .035 flux core in it. Changed out feed rollers multiple times, they are the knurled ones currently, cleaned out liner played with all settings infinite number of times. I'm at a loss. It will produce a decent arc initially than seems like it's cutting out or cuts back almost like I'm trying to weld rusty or non prepped steel. Yeah my old smaller Lincoln ran and worked flawless forever and I'd hit the auto shutoff for duty cycle frequently, unfortunately gave it to a buddy. Suggestions what to test and look at are appreciated at this point I'm all ears.

 

[TripleS]

Try flipping the polarity on it. I had a lincoln once that you had to flip the polarity one way for fluxcore or the other without flux. It is the two connections in the picture under the tensioner

 

[CliffordK]

Number 1... make sure that if you are not using gas, you are using a flux core wire. It should be obvious, but wasn't obvious to me 40 years ago. With non flux wire it will sputter all over the place.

As far as wire feeding, I had difficulties with an old Harbor Freight welder. The issue was that the upper tensioner housing was plastic, and cranking it down tight enough to feed and it bottomed out. Some careful filing and I gave it clearance. But, I also liked to back off the tension when not in use as the plastic housing seemed to deform with a memory effect.

Anyway, get the right wire and it should work OK, although I have seen complaints that the lower powered machines can't maintain a constant power very well.

 

[jjeff]

Thanks for the input, tensioner is cast aluminum I believe, liner is steel it's definitely not the lesser caliber of a HF welder. No gas, and polarity is correct. It's a heavier transformer welder with limited use cuz it never worked like im used to unfortunately it was purchased new at a charity auction or would have been returned yrs ago. Finally tired of looking at it and feel the need to do something with it.

 

[California]

Could a bad capacitor cause that, a good start then worse?

 

[jjeff]

Try flipping the polarity on it. I had a lincoln once that you had to flip the polarity one way for fluxcore or the other without flux. It is the two connections in the picture under the tensioner

So run it like I'm mig welding? Always thought flux core is reverse polarity, which it's set at currently. I did double check after your post including the connections all are tight and corrosion free with no signs of arcing. Darn thing still looks new in there lol. Btw I've tried mig on it with a tank and polarity changed to normal does the same thing.

 

[jjeff]

Could a bad capacitor cause that, a good start then worse?

Unsure? , next step is to pull the cover. Definitely been missing the convenience of flux core welding on thinner metals over the years. Apprehensive of throwing new or used parts at it unless I can figure out what's bad. Almost done with a big spool of mig wire on my 210 plus the tanks low might just convert it to fluxcore to use the spool in the Lincoln.

 

[jjeff]

Could a bad capacitor cause that, a good start then worse?

Any chance you know what values it should have? Do capacitors get worse over time meaning the length of time it functions somewhat ok consistently gets shorter? I think I have a multimeter that can test capacitance. However haven't done much electrical testing for almost 15 yrs though and then I wasn't very good or did testing on stuff consistently, I know enough to get me in trouble or keep me out of it. lol. Currently hoping it's not a circuit board.

 

[California]

I don't know enough about welder circuits to know if a failing capacitor could do as you describe. But that and the rectifiers are the only things in there, that might gradually fail as the welder warms up. Just an uninformed guess on my part.

Anybody know more about this?

 

[yomax4]

Flux core needs to be Straight Polarity or electrode negative. Also if the liner is cut to the wrong length or is getting used up you can cause it to sputter just by over bending your wrist. That can happen if the feed rolls are too loose as well. I like an oversized liner too. If you are running 035 FC, see if they have an 045 liner. Good luck!