tig newb needs help

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mild steel, thought i cleaned it pretty well..getting brown residue, second foto is with it brushed away,, also getting strange bubbles in the beads. set at  140 amps, 3/32  grey, 1/16 filler on fillets.. Attached Images
Reply:That is serious lack of shielding, not a cleaning problem.Could be caused by any or all of the following:1.  A leak somewhere in the gas system, check every connection from the gas bottle to the through the assembly of the torch, could be a loose fitting, leaking flow meter, missing O-ring on torch back cap, etc.2.  Excessive gas flow for the size cup you are using, causing turbulence and air uptake.  Try a gas lens.3.  Tungsten stick-out past the cup too long.4.  Excess arc length, tip to work distance should be less than about 1/8" max.5.  Excessive torch angle, more perpendicular to the work piece gives better shelding.6.  Wrong gas, should be 100% Argon, could this be a MIG mix with CO2?7.  Operator error.Let us know what you figure out.
Reply:thanks, gives me something to try when i get home tonite.but operator error? how could that be???
Reply:Originally Posted by weldbeadthanks, gives me something to try when i get home tonite.but operator error? how could that be???
Reply:i was checking for gas flow, pretty sure it was there ..i'll try the gas lens....might be too much stickout  on the tungsten..ill get some fotos on here tonight..thanks..is the arc supposed to be a very discreet lightning bolt, as in Pulser's avatar, or a more diffuse cone?
Reply:That photo is a plasma arc which is constricted by the plasma gas flow through a nozzle.  A TIG arc is much more spread out and diffuse, and it's concentration diminises rapidly with longer arc lengths.  For the greatest energy concentration and precision control of the TIG arc, you have to hold a very tight arc length.  A super short arc is not always needed, and may not be practical because of dipping the tungsten or hitting it with the filler, but for precision controlled machine welds the arc length may be set as short as 0.030" for something like a 1/16" square butt weld on SS tubing.  This is what a TIG arc looks like, notice the arc length is way too long (several tungsten diameters in length). Attached ImagesLast edited by pulser; 06-02-2008 at 02:12 PM.
Reply:thanks Pulser..I think it was 3 maybe 4 of the things you listed. No leaks, Gotta take gas lenses back to lws, they dont get tight around the tungsten in my torch. right gas.I shortened the stickout, noticed i had a #4 cup which didnt leave much annulus for gas , Lincoln   procedure handbook maded me think it was way too small for 1/4 ms,so i switched from 3/32 ro 1/16 tungsten.Worked on a shorter arc, and more perpendicularity. Discovered my footpedal was cutting off every time i went to reduce heat. i lowered the machine setting and it helped..seems like if i set the machine higher than i needed and tried to control it with pedal, there was a fairly short range of pedal motion  that gave control, so if i set the machine lower i had more control over the heat i was really using. not sure if i explained that well.got some hood time, gotta get lots more. Attached Images
Reply:looking better, work on one thing at a time. Dial in the settings on the machine. (turn the knobs to where it works the best), then your placement of the torch, movement of the torch, placement of the filler, moving in the filler, controling where the bead is going, Just keep practicing. soon you will be able to do it all perrrrrrfect.
Reply:Looks better now... With TIG it takes a lot of PRACTISE and PATIENCE...
Reply:You still have severe porosity.  Are you very sure about no leaks?  How did you check, did you check every fitting, the entire flow meter, and the torch?  You need to plug off the gas flow at the torch, pressurize the system, and check for leaks with bubble solution.
Reply:You are using an ER type filler not an RG type right?The basic oxy fuel fillers don't contain any deoxidisers
Reply:Can you post a pic of your torch with tungsten, so these guys can see your stick-out and tungsten condition? I think a #4 cup is too small for good coverage. I beleive for 1/4" you should be using a 3/32" tung not 1/16". My arc is a crisp white when my tungsten is clean. Once contaminated, it gets a green tint. You must stop and clean it or the porosity will follow the weld across. There can be NO bulge above the ground taper, which is where the contaminants wick to.Stick-out should be no more than 1/2 the cup size; #4 cup = 2 sixteenths stick-out = 1/8" MAX. Shorter is better but you have to be able to see the puddle. Fillet welds allow a little more stick-out because the joint helps contain the gas. FWIW: I use a #8 cup for max coverage and have few issues with it being too large to fit up to my weld.hotrodders point: "You are using an ER type filler not an RG type right?"RG rod will spark like a fourth of July sparkler, contaminate your tung and turn your arc green within seconds of starting your arc.Last edited by Craig in Denver; 06-03-2008 at 04:42 PM.9-11-2001......We Will Never ForgetRetired desk jockey. Hobby weldor with a little training. Craftsman O/A---Flat, Vert, Ovhd, Horz. Miller Syncrowave 250
Reply:That is strange indeed!We had the machine running just fine Saturday..Are you sure the wind isn't a factor?...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:Good point Zap.  Weldbead, the cooling fan feels good when welding, but isn't so good for the shielding.  Have you got things figured out yet?  What did you find?
Reply:many thanks to all responders.am using er70s-2. Have moved indoors to eliminate wind. have about 15cfh on the meter and feel the gas at the cup. I can hear a click in the machine when postflow ends and can see a change in the surface of the cooling "pimple" when the gas flow stops. Will post fotos tonight of torch and tungstens. Noticed when grinding that there is some discloration on trhe tungstens   surface..got all set up yesterday to practice,  couldnt get an arc. tried  combinations of collets/sizes, amps, no arc. said piss on this, tried to burn some 6013, no arc. Golly i thought TA is dead.  said some bad words..wrapped up cables.. heard clump.. looked down saw lug from work cable that goes into machine on floor, where it fell off cable. Tightened her up, set it all up to tig, and had an arc. Ruined half a dozen tungstens in a REAL SHORT TIME,  and quit , happy that ta was working again. Tonite i try the gas lens..how much stickout and cfh? will post fotos, thanks again to all..
Reply:Originally Posted by weldbeadTonite i try the gas lens..how much stickout and cfh? will post fotos, thanks again to all..
Reply:Originally Posted by weldbead Have moved indoors to eliminate wind.
Reply:closed the garage door. soap tested  from top of argon tank to where the hose enters the machine.no leaks.used no filler, trying to keep it simple  for  now.first foto-clean m,etal, clean area of table2nd-gas lens 1/4 stickout,15 cfh3rd-ground tungstens exhibiting discoloration back to the collet it seems-is this ok or should the be without disccolorati0n?4th-5th--noted a white haze . The short one on the right i dipped and restarted  with new tungsten.more follow... Attached Images
Reply:more fotos: Attached Images
Reply:couple suggestions:clean the steel, it should be shining.  Dont just wire wheel it, grind it clean and smooth.  If you try and weld over the mill scale it will pop off the plate and contaminate the tungsten.  maybe you have, its kind of hard to tell.if you dip the tungsten, and you have alot of contamination, dont just grind it down.  Take a pair of pliers and grip the tungsten behind the contamination and break off the the contaminated section by smacking it on the side of your welding table, in a shear motion.  Make sure you are using a grinding wheel for tungsten only, dont grind anything else on the same wheel.The discoloration is the tungsten getting hot without a shielding gas.  Probably from grinding it. Try not to let the tungsten get too hot when your regrinding your point.Your welds are looking much better.  Those suggestions may help you, they may not.  Thats just the way i do things.
Reply:Originally Posted by weldbeadclosed the garage door. soap tested  from top of argon tank to where the hose enters the machine.no leaks......3rd-ground tungstens exhibiting discoloration back to the collet it seems-is this ok or should the be without disccoloration?4th-5th--noted a white haze .....
Reply:i have been grinding the steel to shine. it seems to have pits, im taking it down till they asre small..maybve i need to grind them  and whatever crap they contain  absolutely off ? after grinding ive been hcetone and wi[ping it off with a rag.  didnt try to gert inside the machine to test gas joints. will test the discharge side tonight..