MIG issues

[Dan Crabtree]

We had a millermatic 200 thats about 20 years old in our shop and over time it got weaker and weaker until one day it quit welding altogether. I noticed the handle heated up on the gun and when I took it apart I noticed that it had been repared with electrical tape before and now all the wires were fried and the whole gun was shot. So yesterday I ran out to the welding supply and bought a new gun for it. I hook the gun up and it runs fine for awhile and then I noticed the wirefeed was not quite right. The wire was binding up somewhere in the torch hose or head and causing a birds nest. I took it out and re ran the wire and re-adjusted the tension on the rollers. Then I had the same problem so I flipped the rollers over (im running .035 wire and the rollers are for just .035 I belive, couldnt find any other markings.) and changed the tip and I got it to weld for awhile with no issues but it seems like the rollers might still be slipping. Is there anything I forgot to do?

[cpd23]

Check the wire and make sure it does not have any rust or dirt build up on it.

[stretch]

I don't know a lot about Migs, one thing I have heard about is the liner wears out. The hose up to the gun has a liner in it that has to be replaced. I know of two that have been replaced. I think that would make the rolls slip or ball up because of friction in the liner.

[Covforge]

If your lineris shot try to replace it with a vinyl lined one like you would use for aluminum or stainless. They don't kink like the all wire ones, and last alot longer. We learned the hard way.
Travis

[Mills]

First check for or confirm you have clean wire. Then make sure that it is clean. and then ... welp thats the idea. Also If you have a fresh roll you may want to try it as well. I watched one fellow fight with a MIG and when he changed to a new spool the trouble went away.
next step, Dan I take it you have a new liner?
Then if the rolls are slipping they may be dirty, run a tip of a pocket knife in the groove and see what happens.
If they are slipping and more tension causes a bird nest then it is time to look at the system starting with where the wire exits the rolls and goes into the gun. Strt setting and tightening everything. there are other things but try all that then ask again if needed.

[Thomas Dean]

20yrs old, first gun replacement....replace the liner. Not real expensive and it most likely needs it. Most big shops that use MIG will need to replace a liner every 6 months or so. The service manager we use at the plant ( he is Miller trained) has several shops that they service that are replacing liners at this rate. Saves in the long run with down time.

You may also think about wiping the wire prior to entering the drive rolls. I use a cigarette filter on mine, both at home and work. Cheap, and the fibers in the filter will clean the wire and leave no residue. Learned that little trick 30someoddyearsago If you need it you can purchase a small can of wire lubricant and place a couple of drops on the cleaner, this helps tremendously with the feeding of wire. Check you local welding supply for this, IIRC, it is about $3-5.00 a can. Will last a long time.

Check your tip. A good cleaning with tip cleaners may be needed. If the tip cleaner doesn't do the trick then replace the tip. Often a small piece of splatter will 'weld' itself to the end and cause problems. I have (in extreme cases) filed the end of a tip and cleaned the orfice with a tip cleaner due to this. (best if you can replace the tip tho.)

If the gun is still getting too hot you may need to replace the entire lead. It's kinda like if your stinger gets too hot in your hand you can check the ground and/or stinger lead for a bad connection repair/replace as needed and presto changeo the stinger no longer gets hot. The same with the gun.

Sorry about the length but hopefully something here will help. Good luck.

[Hillbillysmith]

Definatly the liner. If it's new, make sure it's in properly. It's a common mistake to put them in wrong.

[Ice Czar]

Id agree with a best guess as the liner, especially since with the gun replacement it my have gotten a bit twisted, while Im very much a welding newbie one of the issues Ive had to deal with (Miller 210) has been a twisted liner, frayed liner, and given I may be welding in all sorts of odd positions (inside a spiral staircase) keeping track of the gun orientation\twist and radius of the feed

[Ten Hammers]

For the sake of arguement I assume the new gun ( lead ) came with a new liner but don't know. As noted starting at the wire end, check the feed tubes and rollers for clean and alignment. If old liner you can remove it and clean it with brake parts cleaner or soak it in carb cleaner and replace it with new one. Then have a clean liner to exchange. Clean ( good quality ) wire is a must. Many folks here have years more experience than I. THese things I have listed may solve your problem. A Nice cheap little clip on felt wiper with some magic juice that they sell in a can may keep the nasties from entering the first tube and then on down the line. good luck. The liner may or may not have a booger on EITHER end as it enters the lead ( or gun end ). Think of this as a cable housing and you want free passage of the wire through the liner ( housing) with no bind.

[rescuediver]

If you find that your wire had rust on it you probably need to replace the liner even if its fairly new.It only takes a few feet of dirty wire to ruin a liner. Inspect your wire before firing up your machine every time. Also, there is a difference in wire. Stick with a good brand such as Pro-star or Lincoln super glide. Hobart makes a good wire too. Wire lube pads are a good idea too.