setting gap on a Ltec tig

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I have and Ltec heliarc welder.  I am trying to weld AL and I simply can't start an arc without scratching the tungston.  Once I get an arc i can weld fine for the most part, but the tungston get contaminated and i get poor weld quality.  It's driving me crazy.  It's a HF welder.  I read that some guys can strike an arc from an inch!  I have to scratch.  Here's a pic.I have read through this forum on several threads and it appears that i might need to set the gap on the HF resistor thingy? (I'm clearly not an expert)  Does that sound right?If this sounds like the case then is this what I need to set the gap on?  (it's clearly dirty and need to be cleaned)If so then what do I set it to?I have no clue where to get a manual for this  I'd rather not have to take it to a shop if this could be the main cause.I'm mainly using 8"x1/4"flat and 2"x3" 1/8 wall box right now.  2/32 green pure tungston100% argon 20 psicurrent at 160i have arc force on 7 of 10.  (not sure what this is though. Any lower and it doesn't get hot enough.)achigh freqfoot controli think a #2 cup.  here's a picNow I haven't been welding a long time.  This is my first tig ever.  I have used them before but very seldom.  I am learning as I go.  Here's my current job.onto thisHere's one of my better(ish) welds.I won;t show pics of the bad ones cause it's embarassing. I know I still need alot of work on setup and control, but I'll get there in time.  Lots of time.So any help would be greatly appreciated.Love the forum guys,Tim
Reply:I have almost the same machine, slightly different front so it's probably a different year. My HF works fine on Mild/stainless steels but was giving me the same problem as your on aluminum. Those are the contacts and yes that is what needs to be cleaned and set.  I don't have a manual for mine but what I did was to take them out and then using a flat plate of steel and some fine emery cloth on top of the steel I made the contacts flat and shiney smooth again. I reinstalled them  and set them to 0.015" gap as per my lincoln manual for another tig machine I have and the HF works fine now on both aluminum and steels.Good Luck
Reply:Awesome thanks. The gap on it right now looks like its almost a 1/16 of an inch!  When I was reading what others were setting theirs too (.008 or so) I was like wow. This isn't right. Is there anything I need to do to the machine before I do this?  Is their current hanging around in the machine?  I'm running it on 480v and I don't like electrical shocks!!  Haha! Plus I don't want to damage anything. Thanks for the help.
Reply:I'm no electronics expert but I have cleaned and set the gap on many contacts for tig machines over the years and never been shocked. I just unplug the machine and go at it, as far as I know it is safe to do so.  I always take that opportunity with the cover off the machine to wheel it outside and using clean dry compressed air give the insides of the machines a good cleaning. Do this before cleaning and setting the gap so as not to blow a bunch of dirt into the clean contacts.RegardsER70S-2
Reply:If you want a tighter arc, less wandering, set the CLEAN contacts to .008, it will increase the frequency while reducing the intensity. Unless your welding heavy aluminum, then the .015 should be your setting. You will also find it alot easier to control as well as see your weld-pool."SOUTHPAW" A wise person learns from another persons mistakes;A smart person learns from their own mistakes;But, a stupid person.............never learns.
Reply:So, this welder is new to me and for sure used!  Well... older and slightly used.I set the gap to .015 and then .008 last night.  I stayed with the .015 as the puddle appeared easier to control, as "papabear" just noted.  It still didn't strike an arc without contact though.  I proceeded to clean any connections I could get to.  That did the trick for starting the arc with no contact.  YAY!!But now I can't quite figure this out.  I am having trouble getting heat to the material where I'm working...  I guess it's hard for me to explain.  I think this because 1st - the material isn't transmitting or holding heat like it was on other welds.2nd - i can't get a good weld pool going.3rd - the tungston is melting  or balling up so much that it sucks back up into the cup.  I'm working a little farther away from the ground now and maybe that has something to do with it?  I'm working about 8 feet away.I read that there's an amp limit on tungston size.  Could this be my issue?I also read about reversed polarity.  this i know is not the problem.I have 3/32 green tip in there now.  I was thinking of trying gold cause I hear it holds up better.  I'm only working with 1/4" and 1/8" wall material showing about 160 amps for currant and I still don't know what the arc force really does.  I know it's not making the weld any different right now under these circumstances!All these things above are what I would do for the "trial and error repair method."  I'm not sure if these will fix it though.I had dreams of plugging this welder in and having no issues, but...  HAHA  Not this time!At least I learning about what to look for.I really appreciate the helpful info you all have, cause I just don't have anyone in the area I know well enough to pick their brains and I don't want to be "that guy" at the supply store or bugging them on the phone.Thanks,btw  I did clean the contacts so they were almost polished and showed no scratches.Last edited by HMS_Tim; 07-16-2009 at 06:41 PM.Reason: more info
Reply:Originally Posted by HMS_TimBut now I can't quite figure this out.  I am having trouble getting heat to the material where I'm working...  I guess it's hard for me to explain.  I think this because 1st - the material isn't transmitting or holding heat like it was on other welds.2nd - i can't get a good weld pool going.3rd - the tungston is melting  or balling up so much that it sucks back up into the cup.