DC Tig welding Tungson burning up!

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Hi, I have thermal arc 150 dc tig. It had been running fine until recently. Everytime I start an arc, it sparks, and burns the tungson back right away. I'm using 2% thoriated 1/16" tungson and straight argon at 15cfm. I'm welding 16 gauge mild steel. Workpiece is positive and torch is negative. Any ideas on why this is happening? It's been driving me nuts. I've used different tungson, up'ed the argon and still burns up.
Reply:Check for argon leaks at all connections. Also check hoses.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:Try switching your polarity and see what happens
Reply:Did you change ANYTHING between this happening, and the way it was when it worked?Pretty common to roll a wheel over the lines in a crowded shop. Or the line gets kinked, pulling it into position without looking.If you changed bottles, could be a bad batch of gas.If you changed lenses or collets, the torch may not be assembled correctly.Check everything, methodically. Are you the only person with access? Could someone be jacking you around? There's a long list of evil things that can be done to classmates while they try to weld cupons...Trev
Reply:Double check polarity, is there any chance some one could have used your machine and switched leads around on you?Any chance this started happening when you switched argon bottles?old Miller spectrum 625 Lincoln SP-135 T, CO2+0.025 wireMiller model 250 and WP-18V torchCraftsman 100amp AC/DC and WP-17V torchCentury 115-004 HF arc stabilizerHome made 4 transformer spot welderHome made alternator welder
Reply:sounds like you're on DC reverse.Operating Engineers Local 3Lincoln SA 200Victor TorchDewalt Grinder10 lbs SledgeWhat more do ya need!
Reply:Okay, there is an gas leak right where my torch gas hose connects to the front of my machine. It leaks out of the middle, like the nipple isn't keeping sealing properly. Should there be some kind of o-ring on the nipple to keep it leak proof? If not, do i have to buy a whole new torch assembly? It is a black gold torch with gas valve....which i dislike since i dont need it.
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Reply:I don't think that would do it, I have welded stuff without turning on the gas at all before and didn't "burn up the tung". Like mentioned the only time I have seen it burn up is when the polarity is switched.12v battery, jumper cables, and a 6013.I only have a facebook page. https://www.facebook.com/pages/VPT/244788508917829
Reply:The polarity is not switched. Triple checked it. Torch on negative, ground on positive....which it was that easy lol I weld at home and I am the only one who uses the machine. There is no gas coming out of the torch.Last edited by luke2; 02-22-2015 at 01:40 PM.
Reply:Even with a leak in the line some gas will still get out the nozzle. Check for a clog in the torch. Also, I know you have the polarity correct, but try it backwards just to make sure.Ian TannerKawasaki KX450 and many other fine tools
Reply:Originally Posted by luke2Okay, there is an gas leak right where my torch gas hose connects to the front of my machine. It leaks out of the middle, like the nipple isn't keeping sealing properly. Should there be some kind of o-ring on the nipple to keep it leak proof? If not, do i have to buy a whole new torch assembly? It is a black gold torch with gas valve....which i dislike since i dont need it.
Reply:okay, went back out and repluged everything in....no teflon tape on the threads...tungson didnt burn up this time. It did spark a lot though as i am still leaking gas where the hose connects to the machine. Not sure what to do next.
Reply:you can get those fittings from your LWS with a long barbed nipple on the end. You can cut off the old fitting and put the longer fitting on and secure it with a clamp.Operating Engineers Local 3Lincoln SA 200Victor TorchDewalt Grinder10 lbs SledgeWhat more do ya need!
Reply:you said you have a manual gas valve? is it on?bosses stuff:trailblazer 325maxstar 200my stuff:sa 200fronius transpocket 180100 amp Lincoln w/f97 f350 DITKevin
Reply:Originally Posted by 92dlxmanyou said you have a manual gas valve? is it on?
Reply:just checking. i work with some awesome welders that still pick up my torch and forget to turn gas on lol, it really happens a lot.where your gas plugs into your machine, have you checked the "seat" in the female side for obstruction?this is a two hose setup right? one plugs into your neg. lug and one screws in for gas?does the machine leak constantly? like the solenoid is stuck open? or does it just leak when you light up?the leak at the machine needs to be fixed, but check where your gas hose connects in with your power too just to be surebosses stuff:trailblazer 325maxstar 200my stuff:sa 200fronius transpocket 180100 amp Lincoln w/f97 f350 DITKevin
Reply:and just to be sure, we are talking about it leaking on the output side of the machine right? not the input side?bosses stuff:trailblazer 325maxstar 200my stuff:sa 200fronius transpocket 180100 amp Lincoln w/f97 f350 DITKevin
Reply:Only time I've burned up tungsten was when I had it on DCEP (forgot to switch it back after stick welding).You should never be putting teflon tape on those fittings – no pipe dope either – nothing except a wrench.
Reply:Originally Posted by 92dlxmanjust checking. i work with some awesome welders that still pick up my torch and forget to turn gas on lol, it really happens a lot.where your gas plugs into your machine, have you checked the "seat" in the female side for obstruction?this is a two hose setup right? one plugs into your neg. lug and one screws in for gas?does the machine leak constantly? like the solenoid is stuck open? or does it just leak when you light up?the leak at the machine needs to be fixed, but check where your gas hose connects in with your power too just to be sure
Reply:The leak may or may not be the cause of your problem, but the location of the leak indicates either the hose itself is not sealing on the fitting, or it has been cut where crimped, or nearby....or the actual fitting is compromised.Hobart Beta-Mig 2511972 Miller AEAD-200LEMiller 250 TwinNorthern Ind. Hybrid 200Longevity Stick 140Longevity Migweld 200SThermal Arc Pak 3XR
Reply:Originally Posted by luke2Yes it is a two hose setup. I checked the female end and it looked fine. Only thing i noticed last time when tightening down the male part, was once it got so tight the female end would also rotate...not sure if it should or not.Solenoid is good. In the picture attached, it leaks where the arrow is pointing. It doesn't leak around the threads at all.
Reply:Originally Posted by dave powelson"Aggressive tightening of this oversized (from the teflon taping) nut can swell or distort the mating female fitting,creating a permanent leak, until the female fitting in the machine is replaced." Quoting meeself from post 12--- Since the female connection in machine face has rotated from aggressive tightening due to teflon tape,this may have done something to the gas hose connection on the backside, etc.; which is determinedwhen the female fitting is replaced.Using teflon tape on line contact fittings is bad juju, despite what the 'experts' prattle.
Reply:Dave is right.If the gas gets past the seating surface of the nipple, no Teflon tape will help, because the gas will leak around the backside of the fitting, without having to pass through the threads.Hobart Beta-Mig 2511972 Miller AEAD-200LEMiller 250 TwinNorthern Ind. Hybrid 200Longevity Stick 140Longevity Migweld 200SThermal Arc Pak 3XR
Reply:Originally Posted by geezerbillDave is right.If the gas gets past the seating surface of the nipple, no Teflon tape will help, because the gas will leak around the backside of the fitting, without having to pass through the threads.Originally Posted by luke2It was leaking before teflon tape.
Reply:Originally Posted by dave powelsonThen the male fitting may be 'dinged', causing loss of sealing and/or the female seal surface screwed upfrom tightening of the damaged male fitting. Line contact fittings seen in hoses and the regulator to bottle valve are precision, soft brass and damagedquite easily. I know from first hand events. One time drop on floor for a flat spot or ding and they can leak.The teflon tape still may have expanded the female fitting. It should never be used on line contact fittings.If the male torch end ferule doesn't look dinged, then connect this fitting to another machine, turn on gas and see ifit leaks--which then means the torch ferrule is damaged.Connect a known, non leak torch to the problem machine to check the sealing of the female in the 'bad' machine.In any case, you need to take off machine cover and LOOK at what's-what from turning that female fitting.More than likely, you'll need to get a factory part to replace the female.
Reply:Luke-if you post your location, others may be able to point youto a factory service shop. For example in Sac--it's All Phase electric--(for Miller, Lincoln, Thermadyne, etc.)they can order factory parts and probably save time and $ over having togo thru the bureaucracy of the LWS.Blackbird
Reply:Originally Posted by luke2The polarity is not switched. Triple checked it. Torch on negative, ground on positive....which it was that easy lol I weld at home and I am the only one who uses the machine. There is no gas coming out of the torch.
Reply:Only 2 things will burn up your tungsten. No or lack of argon gas or wrong polarity.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Originally Posted by RojodiabloYou just answered the question 100%. Fix the gas leak; then test via pointing the torch in your ear to ensure you are hearing and feeling gas flow. Problem will be solved 100%.
Reply:Originally Posted by dave powelsonLuke-if you post your location, others may be able to point youto a factory service shop. For example in Sac--it's All Phase electric--(for Miller, Lincoln, Thermadyne, etc.)they can order factory parts and probably save time and $ over having togo thru the bureaucracy of the LWS.
Reply:Took the cover off. The gas hose that was going into the female connector was kinked pretty badly, undid that. Put it all back together, I get a puff of gas out of the torch now but then it dissipates pretty quickly. Tested it to see if it was leaking at the connection again, and it is. What is the piece that slide in the torch hose called that goes into the female connection? I need to order a new. Note sure if there is a certain size for the or not either. I did try to weld and it hissing and sparking like crazy...did burn up the tungson though.
Reply:I'm not sure you can replace that part, you may need to get a new hose. Someone else will have more info about replacement.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:OP needs a new torch.Miller Millermatic 252Miller Syncrowave 200Liincoln AC-DC 225Victor O-A Set
Reply:Originally Posted by luke2Took the cover off. The gas hose that was going into the female connector was kinked pretty badly, undid that. Put it all back together, I get a puff of gas out of the torch now but then it dissipates pretty quickly. Tested it to see if it was leaking at the connection again, and it is. What is the piece that slide in the torch hose called that goes into the female connection? I need to order a new. Note sure if there is a certain size for the or not either. I did try to weld and it hissing and sparking like crazy...did burn up the tungson though.
Reply:Update: Went to my LWS place with my torch explaining it was leaking. He hooked it up to a tank, sprayed so water on my hose and the water bubbled up like crazy. He took pulled the sheathing down and my hose is worn out and cracked pretty bad. I ordered a new one so hopefully that fixes the problem.
Reply:Originally Posted by luke2Took the cover off. The gas hose that was going into the female connector was kinked pretty badly, undid that. Put it all back together, I get a puff of gas out of the torch now but then it dissipates pretty quickly.
Reply:Can you hear gas coming out of the welding end of the torch? Light a match and try to put it out with the argon coming out of the torch.Lincolin Power Wave 450, Lincoln Powermig 255, Lincoln Pro Mig 140, Lincoln Squarewave Tig 275, Miller Big 40 G(with Hobart Hefty suitcase), Thermal Arc 95S and Esab PCM875 in an already full machine shop.
Reply:I read most of the replies and even with a terrible leak it wont react as described....Really sounds like a polarity issue.....Electron Positive will smoke a tungsten in a blink.....get a picture of your tungsten Last edited by B_C; 02-24-2015 at 09:18 PM.  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:Originally Posted by B_CI read most of the replies and even with a terrible leak it wont react as described....
Reply:I have set my tank on my hose going in to the unit, that only took me an hour to figure out.Regards,RobGreat Basin WeldingInstagramBlue weldersRed weldersMy luscious Table DIY TIG Torch cooler
Reply:The hoses used on tig torches are pretty brutal for repairing. The way they stretch and rip makes it almost impossible to fix. In the future, would suggest picking one of these up, which would have helped you diagnose your problem right awayAvailable from ESAB, PN 19043Can be used on mig or tig torches and shows what you are getting at the tip
Reply:Originally Posted by thecobraThe hoses used on tig torches are pretty brutal for repairing. The way they stretch and rip makes it almost impossible to fix. In the future, would suggest picking one of these up, which would have helped you diagnose your problem right awayAvailable from ESAB, PN 19043Can be used on mig or tig torches and shows what you are getting at the tip
Reply:Put a balloon over the end of your torch & see if it inflates, , ,What is the sound of one knee jerking?
Reply:Originally Posted by rlitmanWhy do you feel your response should be taken seriously if it is written in bold Comic Sans?A leak in an argon line will not only reduce argon flow coming out the torch, but may suck in air through the venturi effect.  This will absolutely cause the tungsten to be burned up.
Reply:Originally Posted by B_CHmmmmmm  I guess because Im 67 and have a hard time seeing Small print  and I like that type FONT.... the description was it burned up INSTANTLY....low argon flow doesnt BURN UP INSTANTLY .....Just replying....Quote:  burns the tungson back right away.
Reply:Anything Else Im doing wrong?    12 posts and your already criticizing a regular on here.......Last edited by B_C; 02-27-2015 at 05:17 PM.  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:Just about had it with  the guys that feel it necessary to give me a bad time for trying to help new welders on here....really didn't want to go there but if you are a better welder fabricator than me and others why aren't you helping the new guys?  Screwing with me and other welders just makes you look like an azz not us.......keep that in mind the next time you need to slam someone....This forum is for helping not criticizing.....you don't like my font or its too big....REALLY?    Suck it up buttercup   I'm not changing anything.......  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:Originally Posted by B_CAnything Else Im doing wrong?