inconsistent arc during welding

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Hi guys. I'm one of those amateur welders. Actually, a farmer/rancher that needs to be a jack of all/master of none types. I've done some welding over the years and if I do enough of it, can actually lay down a pretty darned good-looking weld - especially since I added a gas rig to my Miller 130. Nice clean weld and virtually no slag....should have gotten gas years ago.Here's my question and it's two-fold;When welding clean mild steel, sometimes the arc will stop just for a millisec and then start again. It will cycle on and off as long as I have the trigger pulled - never really establishing a continuous arc. The resultant weld looks like bird doo-doo, reminiscent of my learning days with a Lincoln 225 buzz box. This usually occurs with 18 gauge tubing or similar material. If I'm welding 3/16", the machine lays down a solid bead and there's no problem. I'm actually proud of the job. But when welding thinner materials, I've tried changing wire speed and amperage but can never establish a consistent arc.The other half of my question is how do you see what your welding? It's very hard to see the material being welded. It's much easier to see a stick weld. I've tried lighter shades but I don't want to damage my eyes. Currently I'm using a auto-helmet set to shade 10 (sometimes 9).The machine is a Miller 130, .030 solid wire, 75/25 Argon/CO2. The problem exists with either flux core or solid wire.What am I doing wrong?
Reply:For the intermittant arc, try a new contact tip.It is harder to see with MIG for me too.  Best suggestion I can give is watch the puddle, not the arc but if you already have experience with stick, you're already doing that.  Another thing to try is better, brighter lighting in general -- sometimes helps.
Reply:I would first change the contact tip.  When it binds you can feel it in your hand.  The gun will have a slight jerking feeling.   Next is feeding.  Roll tension and liner.  If you pull the gun and lead straight as you can, does it go away?  Is the drive roll tension set like the instructioins? You can pull the liner out to clean and inspect.  If there are any kinks, its garbage.  I clean my liners with Shop Solv parts ceaner.  I spray the arasol in the welder end with the whole gun and whip removed.  Take out the contact tip too.  Straighten out the whole affair, spary in the back where the wire goes in till it comes out the front.  Then chase it with compressed air.  You should see a bunch o crap come out.  This should be done every roll of wire.You can also try to hold the wire from feeding at the gun end.  Grab it where it comes out from the contact tip and see if you can stop it.  If its easy, you need more drive roll tension, or clean/replace the liner.DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:I agree with the advice given.  I'd keep a spare liner, too.  With mig I keep spare everything.  (tips, nozzle, diffusers, liners, wire cleaners and wire)Solid wire is more difficult to push than flux core, especially for 110v machines.  Hence, make sure your line is as straight as possible when using your welder.  Also, make sure your tip size is correct, too large a tip can cause arc delay because the wire looses contact with the tip. If you haven't changed liners before, then I would change it rather than cleaning because it could have a crimp in it.  Clean it out of the machine and save it as a backup.  If you change the liner make sure you follow directions.  The liner should be cut off long enough so it is necessary to force it into the gun with the diffuser.  If the liner is cut too short then more feed problems will arise.  As far as seeing what you are welding.  sometimes you have to play with the position of the gun to get the nozzle out of the way.  I usually look for the seam first, then I can find the puddle. Adjustable Autodarkening helmet helps.Hope this helps.I really dislike Mig...I stick weld whenever possible.
Reply:Be sure your drive roll tension is right and your spool tension is right, if the spool is too tight it can cause a surge.***************************************Lincoln AC225 stick welderLincoln HD100 WeldPak flux core wire feed welderThree of the cheapest grinders money can buy
Reply:Thanks everyone for the tips. The manual isn't too specific about drive roll tension. I can stop the wire as it comes out of the gun regardless of how much tension I have on the roller. The roller has both a smooth and knurled groove and it says to use the smooth one for solid wire. I've tried new tips but the liner is original (no laughing, please). I guess I should get one. I have found it's easier to see the weld when I drag the tip towards me, although that's not always possible in some situations. I just wondered if there was something else I could try to improve visibility.Thanks again for all the replies.
Reply:Beware of too much drive roll pressure on the wire it could distort the wire which could also cause feed problems.
Reply:If you can't see properly, you can't weld properly.DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:I bought a set of lenses that fit in the helmet and my welds improved dramatically.  I have bifocals and you cant see out the bottom of the lens with the helmet on.  Now I use shade 12 and can see clearly.  Try to make each and every weld perfect, do not get in a hurry.Thermal Arc 185 TigHTP 200 MigCraftsman O/A1942 Bridgeport Mill12 Ton Hyd PressConsew Walking Foot
Reply:Make sure the ground strap is in good order.....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Very good point about ground lead.  Make sure everything is tight.  Always check simple obvious stuff first.I once took my engine driven welder apart at a job site to check the burshes because there was no arc.  After thoroughly dismantling the machine...wow is my lead under covered with dirt....or could the union have come apart.  Oh well at least I found out that my burshes had much life in them.On the other hand I have an old arc welder.  I removed all union and replaced clamp and electrode holder and in really eliminated sticking and difficult starts.Check the easy stuff first.
Reply:Say WOJEEPSTER, you weld with #12?  Dude, I don't think I could see through it. I also wear cheaters/bifocals for close-up work and found it was a pain to look through the bottom of my glasses. Now I use a full lens and it's much better.
Reply:Originally Posted by wojeepsterI bought a set of lenses that fit in the helmet and my welds improved dramatically.  I have bifocals and you cant see out the bottom of the lens with the helmet on.  Now I use shade 12 and can see clearly.  Try to make each and every weld perfect, do not get in a hurry.
Reply:I guess I'll have to twist the dial to #12 and see if I can see! Bifocals are a great invention!
Reply:When I first started using my mig I experienced a stuttering arc that drove me crazy.  Of course I blamed myself, but try as I may, I just could not get a continuous, smooth bead.  I finally decided it must be the welder, so I started troubleshooting the feed, and found that the wire spool had spokes that were binding on the inside wall of the spool enclosure, as the spool turned.  In addition, the spool had a label stuck to it that I thought might be providing a variable friction.  After removing the label and through the use of large washers on both sides of the spool, I finally got an even, steady wire feed, and good beads.
Reply:Hmmm, good point. I don't think my spool is binding...at least it seems to be turning free when I move it by hand.  I'll have to have a closer look. Thanks for the idea.
Reply:cheater lenses in your hood will help you see better, but you have to play with several to find to right one. Myself, I went to the dollar store and bought several pair of the cheap reading glasses that are always in focus for your eyes, and "ta dah" my welds got better again. Amazing what happens when you ain't bustin your neck tryin to see thru bifocals while lying on your back...You know the story.
Reply:Amen to that! I'm doing the same thing with some cheater lens but the danged joint is still hard to see. Today I drug my welding project out into the bright daylight...hoping to illuminate the joint a little better but the glare on the inside of the helmet glass made it more difficult. I think it's better inside the shop. My welder is still sputtering and spattering on the lighter gauge stuff but works just fine on 3/16". It's really giving me fits. I've got a new liner on order but I don't know if that's going to solve the problem. I fed out a couple of feet of wire from the tip and then cut off enough at the spool end so I could grab it and then pulled the wire back and forth through the gun. It moved freely with no binding so I don't know what the heck is going on. It's very frustrating because the welds look like crap and I know I can do better than that.
Reply:I have students that put the contact tip in finger tight. They loosen and allow inconsistant arc. Snug the contact tips in lightly with your welding pliers. This is an electrical connection.
Reply:That's a good thing to check, thanks. I usually give it a good twist with my pliers when installing the tip but I never thought about the fact that it's part of the electrical connection. As far as seeing the weld pool and joint, I wonder if a good quality helmet might make a difference? I've been using my old welding helmet from the 70s but recently got a cheapie auto helmet from Harbor Freight. It works pretty darned good but do you suppose a high-dollar helmet provides a better view?Last edited by mvintx; 05-13-2007 at 08:45 PM.