grr need help with tig please!

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heyi have a scratch start tig finaly i made an arc and was using some filler, then my tungston started melting !? what happend?how do i start an arc with scratch start? it was just the odd time one would start. i was uing 'red' tungston also i was welding outside the wind wasnt to bad and the argon was on full but i had to keep running in about out to re grind tungsoneany help would be great thanks -Ryan
Reply:I think your polarity might be reversed, on tig your torch needs to be negative and your work positive.  AC will do the same thing (which is ok for alumi work).  Could happen when your current is too high for the tungsten too.  I dont remember the limits, (150a for 3/32?) anyway, youll get it.Your welding steel correct?  A small piece of copper on the work will help you get the flame going.
Reply:Originally Posted by Ryan Bheyi have a scratch start tig finaly i made an arc and was using some filler, then my tungston started melting !? what happend?how do i start an arc with scratch start? it was just the odd time one would start. i was uing 'red' tungston also i was welding outside the wind wasnt to bad and the argon was on full but i had to keep running in about out to re grind tungsoneany help would be great thanks -Ryan
Reply:Reverse the polarity ... shield gas cfm maybe 15 ... no wind
Reply:"Wind wasn´t too bad..."MMM...seems like it was bad enough to melt your tungsten...TIG is mostly indoor, don´t know about doing it outside but might be your problem that you don´t have enough gas coverage....My Babies: HF Drill pressHF Pipe Bender3   4.5" Black and Decker angle grindersLincoln Electric PROMIG 175that´s it!
Reply:Ryan,From memory I think you were welding bike frames. I assume they were steelso your red coded  tungsten electrode would be correct.I remember the tungsten colour codes this way Red = Thoriated   and there is a  T in  sTeel White =  Zirconiated.    Aluminium starts with A the first letter in the alphabet and Z for Zirconated is the last.Mind you these are markings for Aussie marked tungstens. Otherwise,your welding distributor outlet may be able to help you with the correct coding.Electrode negative for steel is the correct polarity. Electrode positive as you have undoubtably noticed, is  far too hot unless your welding with tungstens 1/4" and above.Check out the free info on the web Miller has one http://www.millerwelds.com/education/library.htmlsee the TIG info As a  learner, I would try and minimise breeze. Anything over 4 mph blows your gas away. A technique I learned early is to sharpen several tungstens at once. In this way there is less of a break to your cycle of concentration on keeping your arc /speed,etc together.If you have a few bob spare grab some chemical sharpening paste and some spare tungstens.. It is much quicker than the grinder and safe if you wear a mask.One does not know whats in the dust or fumes.Merry XmasGrahameLast edited by Grahame; 12-26-2006 at 04:56 AM.
Reply:thanks for the advice, today i will weld in the shed just got to move the flamible gas bottle out and a petrol can out, thanks ill do it on steel as its red. Now how do i start the arc with scratch start?thanks alot-Ryan
Reply:thanks for the advice, today i will weld in the shed just got to move the flamible gas bottle out and a petrol can out, thanks ill do it on steel as its red. Now how do i start the arc with scratch start?thanks alot-Ryan
Reply:Ryan, Most of us will have no idea at all of what your type or brand your welding machine is, much less finding anybody that may have used one like yours.Not knowing that makes it a tad hard to advise on specifics as machine procedures in themselves can vary. Myself ,I have no idea of scratch start as I have always used HF start.Did your unit come with instructions ? Have you read them?The link I gave you had thishttp://www.millerwelds.com/pdf/gtawbook.pdfPart 6.1  of that PDF gives some info on how scratch start works. Have a try following those directions.Make sure that your metal is spotless as TIG can,t tolerate dirty metal.Carry this over to your filler as well,make sure it is spotless.Tip! if it is dirty or rusty ,clean with steel wool. Do your homework Ok? and give a report please.Remmember its like oxy welding -form the pool with the arc and melt the filler wire in the front edge of the pool.Get some practice walking the wire through your fingers.Grahame
Reply:You were welding aluminum?  Then your tungsten will ball (i.e. melt the tip), this is normal on ac.  Ive never scratched start so I will leave that to others for the best trick.Various GrindersVictor Journeyman torch200cf Acet. 250cf oxygenLincoln 175 plus/alpha2 gunLincoln v205t tigLincoln 350mpEsab 650 plasmaWhen you can get up in the morning, Its a good day.Live each day like its your last.
Reply:Originally Posted by Ryan Bthanks for the advice, today i will weld in the shed just got to move the flamible gas bottle out and a petrol can out, thanks ill do it on steel as its red. Now how do i start the arc with scratch start?thanks alot-Ryan
Reply:after reading thru all this.. you guys have pretty much covered it all.....harbor failure tungestion...   ...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:if it melted right away, there was no sputtering and the tungsten didn't change color i'll bet you've got the polarity hooked up wrong.  i've done this millions of times(hooked it up backwards).  scratch start takes some getting used to, its very similar to scratch starting with a stick welder, you drag it accross until you get an arc, if you stay still while touching the tungsten will stick.  you'll be doing alot of grinding of your tungstens, i'd advise getting a bunch and grinding them all at once, if you're only using thoriated, or all of one kind for that matter, it saves time to grind both ends, that way you can take it out and flip it around.  only drawback is you can confuse different types of electrodes, well that and burning you're fingertips.
Reply:I use the 2% thoriated tungsten for everything I weld.  Haven't had any problems doing that.