beginner tig welder looking for some advice.

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so i have an older miller maxstar 150 that me and a friend just fired up today.  everything seems to work, but the tungsten was melting back into the insulator when i tried to weld.  i might have been holding tungsten too close to the piece of steel.  the tungsten was 1/16th, has red on the back end of it so i assume it was thoriated tungsten.  i just wanted to see if i have the settings right here, i will attach photos of the settings i had on the welder and hi frequency start box.  could i have been using too thin of an electrode?  wrong type of electrode?  wrong settings on hi frequency start box?  i am using 100% argon, not sure if i should have a mix cause i think what i was testing out the welder on was just mild steel.  i got pure argon cause i was planning on trying to use it to weld thin cro-moly steel.  but i figured i would test it out on this thicker scrap of 1018 just to try it.  any advice?  i did take a tig class years ago but havent had access to one in years.  any advice is greatly appreciated.  -eian
Reply:Is your polarity correct? I don't have to worry about that with my newer Maxstar, but I don't know how your torch hooks up on your machine. I see guys regularly get messed up because the kids flip the switch from DC - to DC + to mess with people with the machines at the tech school.100% Argon is correct. It will do anything that machine will handle. You don't need any sort of mix.1/16" should be good from around 60 to almost 150 amps DC - according to some charts. I typically use 3/32" in that range, but either will work.My thoughts no seeing the tungsten is you either are trying to tig DC+ or you are having a gas flow issue and aren't getting gas. I'd start with those things and work from there..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:gas seemed to be flowing fine, but you might be totally right about the polarity.  i think i might have hooked it up dc +, i should check that.  thanks.  and the 3/32 tungsten is a good point.  was looking at the miller manual for my welder, and hf box, and it mentions how to connect for dc+ or dc - thanks
Reply:As dsw said check your polarity
Reply:the electrode is connected to the positive terminal on the power source...  so i guess that i was trying dc + ?  i should reverse the connection?  so the ground clamp is conneted to + and the torch / electrode is connected to - ?
Reply:and it shouldnt matter that everything is routed throught the hf start box?  just reverse the + and - leads from the power source to hf box so that - is connected to torch and + is going to ground?  just want to confirm i understand.
Reply:Electrode negative for DC tig welding. Also known as straight polarity.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:When in doubt, you can always take the HF box out of the equation. You can do scratch start tig in DC without HF. HF is only really critical with Ac tig. HF does make it easier to start the arc in Dc if you are not used to doing tig, but I teach scratch start tig all the time. The only question I might have is how your torch/gas is connected. I don't know how everything you have is set up, so I really can't comment to much on what to try/do. I don't have a separate HF box on any unit I use. The Maxstar and Syncrowaves I use all have Hf start built in. The XMT's all either get used in lift start or scratch start and have gas valves on the torches for gas flow..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Switch your HF to continuous and use 3/32 tungsten.  By no means am I an expert, I am just learning tig myself....    But this is what helped me.EDIT...I just noticed you are welding DC I use continuous on AC/ aluminum...   carry on... Last edited by John T; 02-15-2014 at 06:55 PM.Miller 211Hypertherm PM 451961 Lincoln Idealarc 250HTP 221  True Wisdom only comes from Pain.
Reply:i was told that the hf box was good to use as otherwise i might get tungsten contamination when welding 4130 steel using scratch start.  but probably isnt necessary for practice.... the other reason i thought it was maybe good to use was because this welder has an amperage knob stuck on 150 amps and so the amperage can only be controlled with the pedal, so i thought the arc would be able to form at less amperage with the hf box which would maybe prevent the breaker from tripping that it is connected to.  i am running the welder on 220 v on a 30 amp circuit.  the welder is rated 26 amps @ 220.  so i figured that was cutting it a little bit close... and all the cables were configured to go through the hf box.  i definitely had the electrode +, so that seems like the solution, but i need to wait to get the new alumina and tungsten in the mail before i can try again, as i melted my one tungsten i had on hand and broke the one alumina cup that came with the torch... oh well.
Reply:Which max star 150 do you have? The 150s or 150stl?JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Snowproe he's got one of the really older Maxstar 150's.  Not the ones in current production The older boxy ones..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:its old, from around 1989 according to the manual i found
Reply:It's 99% polarity related. I did the same thing when i started out...my welding leads were marked by someone...incorrectly. I burned that tunsten back so bad I had to repair the torch.Switch up the polarity...smooth as butter.HF is nice, but you can do scratch start no problem. Just work it down like a stick and be quick when the arc starts. For steel and stainless I 've found a little contamination on the torch tungsten doesn't really affect the weld that much if at all. Aluminum, that 's a different story.15 CF/Hour is a good starting point for a 3/32 tunsten size.I like continuous HF, but you can do start only for steels  (DC straight).HF makes no difference to loading. It's only for starting the arc before touching the work. On AC it helps maintain the arc through the 0 current crossovers.Also, LEAK CHECK your torches with a some compressed air set at 10psi or so. Use soapy water to check joints/orings etc. This will save you a lot of messing around and head scratching!!Chay