Having trouble starting arc in AC

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I'm just now playing with the AC on this machine and am having a lot of trouble getting an arc started. Pulse is off (as far as I know), the gas is pretty low although it still registers 20cfh on the flow meter consistantly. I'm using the pedal and have the amperage ajusted to 120 at WOT. Tried messing with the collette body because un like my weldcraft torch the torch on this machine is touchy and you have to make sure the back cap seats just perfect or you will have trouble starting an arc as I found out in DC. Anyway, can anyone spot what I'm doing wrong? Really old (&faithful) Lincoln SA-250 Diesel, &Longevity 200P
Reply:I'm starting to wonder if its the welder, it wil start up every 5th attempt or so and the arc stays sustained until I let of the pedal or switch then try again and it refuses to work. Also the tungsten is getting very hot itself, when I let off its glowing orange, Im not sure if this is normal for AC or not. I'm gonna order a new bottle of Argon & try that. Any input at all is very appreciated.Really old (&faithful) Lincoln SA-250 Diesel, &Longevity 200P
Reply:Have you switched the high freq to continuous?
Reply:Originally Posted by SupeHave you switched the high freq to continuous?
Reply:Straight line should be DC?Square-wave pattern should be AC (square wave)?If there is/was a pic there Hummer, I can't see it.  Suggestion to put pics as an uploaded image to weldingweb, not as your own images.  The best laid schemes ... Gang oft agley ...
Reply:Originally Posted by MoonRiseStraight line should be DC?Square-wave pattern should be AC (square wave)?If there is/was a pic there Hummer, I can't see it.  Suggestion to put pics as an uploaded image to weldingweb, not as your own images.
Reply:Dang,I guess if they included an "Owner's Manual" with those chinese crackerboxes, they'd cost nearly as much as a Miller/Lincoln/Thermal.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Originally Posted by SundownIIIDang,I guess if they included an "Owner's Manual" with those chinese crackerboxes, they'd cost nearly as much as a Miller/Lincoln/Thermal.
Reply:Hummer,Seriously though, anytime your argon gets that low, you're asking for problems.I would tend to be focusing on your preflow and postflow of shielding gas.  Sounds like you're not getting sufficient postflow to properly protect the tungsten.  Inadequate preflow will make the arc difficult to impossible to start.As to how to go about checking it.  I don't have a clue.  On my sync, postflow is right up front on the panel.  Preflow requires going to a "hidden" menu.Tank up and go for it.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Originally Posted by SundownIIIHummer,Seriously though, anytime your argon gets that low, you're asking for problems.I would tend to be focusing on your preflow and postflow of shielding gas.  Sounds like you're not getting sufficient postflow to properly protect the tungsten.  Inadequate preflow will make the arc difficult to impossible to start.As to how to go about checking it.  I don't have a clue.  On my sync, postflow is right up front on the panel.  Preflow requires going to a "hidden" menu.Tank up and go for it.
Reply:The tungsten will always being glowing at the end of a weld- it's white hot while welding and with AC has to endure more heat than with DCEN. That's what post flow is forThe switch circled in red is very likely pulse on/off. Post flow circled in yellow appears to be set to zero! As said, if the tungsten is becoming oxidised for any reason (settings, micky mouse torch back cap or other leak etc) then arc starts can be affectedA lot of machines have adjustable arc starting parameters in a hidden menu but i doubt this will have either- especially if a manual is an extra  Attached Images
Reply:Originally Posted by hotrodderThe tungsten will always being glowing at the end of a weld- it's white hot while welding and with AC has to endure more heat than with DCEN. That's what post flow is forThe switch circled in red is very likely pulse on/off. Post flow circled in yellow appears to be set to zero! As said, if the tungsten is becoming oxidised for any reason (settings, micky mouse torch back cap or other leak etc) then arc starts can be affectedA lot of machines have adjustable arc starting parameters in a hidden menu but i doubt this will have either- especially if a manual is an extra
Reply:It'll be a different colour depending on the extent of oxidation. It'll go from greens/golds to blue and finally a manky dark grey- like a burnt weld. Shouldn't be any change of colour after use if shielding is right (and it hasn't been dipped in the weld/filler)
Reply:Originally Posted by hotrodderIt'll be a different colour depending on the extent of oxidation. It'll go from greens/golds to blue and finally a manky dark grey- like a burnt weld. Shouldn't be any change of colour after use if shielding is right (and it hasn't been dipped in the weld/filler)
Reply:They don't include manuals?  It is against federal law not to include an operator's manual with those things.  Many, Many people have been sued that imported things from China and sold them without owners manuals.  Guess who always won and guess who no longer can afford toilet paper?Harbor Freight includes an owners manual with everything now because of this.  It only takes one complaint to the right agency...These manuals must afford basic saftey precautions, operation and maintenance details.  A few companies produce videos for their product as well, but they can, as I understand it be supplimentary, and not be relied upon as the printed document.Last edited by lugweld; 12-04-2008 at 09:28 PM.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:Originally Posted by lugweldThey don't include manuals?  It is against federal law not to include an operator's manual with those things.  Many, Many people have been sued that imported things from China and sold them without owners manuals.  Guess who always won and guess who no longer can afford toilet paper?Harbor Freight includes an owners manual with everything now because of this.  It only takes one complaint to the right agency...These manuals must afford basic saftey precautions, operation and maintenance details.  A few companies produce videos for their product as well, but they can, as I understand it be supplimentary, and not be relied upon as the printed document.
Reply:New devopment this morning. Got the welder to make an arc in AC and do it over & over but get this, the ONLY way it will continuously make and sustain an arc is with 2% Thoriated tungsten.This totaly boggles me, I swapped between the pure & 2% just to make sure it wasnt just a fluke and repeatedly the only way the machine would work was with the red band 2% electrodes. When I would swap back to the pure electrodes it would revert back to popping and acting crazy.Can any please explain whats going on? How should I prepare the tungsten if it only uses 2% electrodes, do I sharpen them or put the machine in DC and make it ball up first?Really old (&faithful) Lincoln SA-250 Diesel, &Longevity 200P
Reply:Before you jump off into something like this,  you should do your homework.  Its not anyone else's responsibility.I have nothing against Chinese products.  I have worked with imported chinese equipment and done the legwork to import.  I asked these kind of questions before the first shipment hit the docks.  Actually before the order was made.  If these products are being sold under the factory name, then the factory is responsible, I think.  But if they are sold under a "branded" name, then it is the owner of the marque's responsibility to ensure the appropriate warning labels are affixed, that all electrical equipment meets Rf requirements set by the US gov, all manuals are in english and/or the user's language.(This goes for shop owner's as well.  They are liable to have any equipment manuals available to the employee/user to ensure safe operation. Etc. Etc. Etc.If none of this has happened or is not existant, then I suggest that these are nothing more than profiteers and not in it for the long haul.  Long haul guys are genuinely interested in preventing and surviving any legal action against them.Last edited by lugweld; 12-05-2008 at 10:04 AM.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:Originally Posted by lugweldBefore you jump off into something like this,  you should do your homework.  Its not anyone else's responsibility.I have nothing against Chinese products.  I have worked with imported chinese equipment and done the legwork to import.  I asked these kind of questions before the first shipment hit the docks.  Actually before the order was made.  If these products are being sold under the factory name, then the factory is responsible, I think.  But if they are sold under a "branded" name, then it is the owner of the marque's responsibility to ensure the appropriate warning labels are affixed, that all electrical equipment meets Rf requirements set by the US gov, all manuals are in english and/or the user's language.(This goes for shop owner's as well.  They are liable to have any equipment manuals available to the employee/user to ensure safe operation. Etc. Etc. Etc.If none of this has happened or is not existant, then I suggest that these are nothing more than profiteers and not in it for the long haul.  Long haul guys are genuinely interested in preventing and surviving any legal action against them.
Reply:Originally Posted by WS6HUMMERThe problem all along was the type of electrode being used, I called my cousin that is a professional TIG welder and he had never heard of a machine that used 2% Thoriated tungsten to weld in AC. He did however say that the Miller Dynasties use pure tungsten for every current though.      The company that sold me the welder has contacted me through e-mail & is supposed to call me later today.
Reply:Originally Posted by crawlerI would question if your cousin was really a professional TIG Welder.  Pure (green) tungsten is NOT to be used on a Miller Dynasty for AC.
Reply:I've read repeatedly that pure tungsten isn't to be used on an inverter welder. Maybe you found out why. Your welder and the Dynasty are inverters. With an inverter, you can use any color you want, except green.I'm glad you discovered this. It's been said never to use green in an inverter, now I think we know why.I've been using a red tungsten on AC for years, in my x-former Syncrowave. Sharpen (blunter than a pencil), truncate, weld. The truncated tip will ball up (chrome like you mentioned), as you weld, so there's no need to do it separately. Your dark blue tungsten is indicating too short of a post flow, but 7 seconds should be long enough. I use 6 seconds for my 3/32" tungsten, up to 120 amps and my tungsten are always light gray after welding.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:Originally Posted by Craig in DenverI've read repeatedly that pure tungsten isn't to be used on an inverter welder. Maybe you found out why. Your welder and the Dynasty are inverters. With an inverter, you can use any color you want, except green.I'm glad you discovered this. It's been said never to use green in an inverter, now I think we know why.I've been using a red tungsten on AC for years, in my x-former Syncrowave. Sharpen (blunter than a pencil), truncate, weld. The truncated tip will ball up (chrome like you mentioned), as you weld, so there's no need to do it separately. Your dark blue tungsten is indicating too short of a post flow, but 7 seconds should be long enough. I use 6 seconds for my 3/32" tungsten, up to 120 amps and my tungsten are always light gray after welding.