Help! bad TIG welds

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Hello,I'm a new member with probably an old sounding problem.  I have a Lincoln Precision TIG 225.  I bought it several years ago and tried it on some aluminum test welds and it worked fine right out of the box.   It has set for a few years in my garage out of the weather but it gets cold in winter and hot and humid in summer (chicago).  I used the welder all last winter in stick mode and had no problems.  This summer I switched the machine over to TIG and I'm having some real problems, more severe with aluminum of course.  I'm having problems with my aluminum welds being very hard to initiate (because I can't get a nice shiny weld pool) and coming out dirty looking and much wider than should be.  My mild steel TIG welds look okay on form but are covered with dark grey (oxidized?) coating.  Stainless welds are dark grey too.This is what I have done working on the problem:  For aluminum I have tried different filler and test pieces of aluminum.  I have to lay the filler rod down flat on the test piece and slide it into the weld or else it vaporizes!  Yes I keep a short arc.  I tried brushing and sanding and washing with acetone.  I have tried different 3/32 tungsten from different lots.  I have tried pure and 2% thoriated pointed and balled.  I bought a new bottle of pure Argon.  I checked the lines for gas leaks.  I tried a different regulator.  Gas valve clicks loudly and I have a good flow coming out the torch.  I tried 15CFM up to 30.  I tried auto, max-clean and max-penitration.  I tried all ranges of amperage.  Yes I had the machine in AC.  I took the covers off the machine and blew all the dust out of it.  I got the repair manual and checked: SCR function on an ocilloscope , diode function, all large resistors, all capacitors, microswitch function, main switch function, all voltages were okay including main supply from breaker box.  HF is functioning and I checked spark gap setting, foot pedal is functioning, I tested my torch on another macine and it's fine, tried different nozzels and gas lens.   I checked my ability on another TIG machine and I can make okay welds, clean nice looking welds.  So what gives?????Thanks for any help,  Roy
Reply:Was it plugged in?Sorry, sounds like you checked everything including the muffler bearings!
Reply:bad gas ?miller thunderbolt 250vlincoln square wave tig 175 prolincoln idealarc mig sp250everlast tig 210EXTeverlast power plasma 50chicago electric (hf) 130 tig/90 arcchicago electric 90 amp flux wire3 sets oxy/acet
Reply:Can you adjust the ac side on that machine? Maybe you have it set at max.cleaning or max penetration?
Reply:I had a very similar problem. I had run out of Argon so I went to the LWS. Got the tank home and tried to weld some aluminum.Problem was the same as yours.....no weld puddle and dirty black soot contamination on aluminum. Steel welds that have a gray look to them. The tank was marked argon. I took the tank back and showed them a test I did. They said that it was CO2 contamination.The manager came by and did a test....he opened the valve a bit and sniffed the gas coming out with his nose above the valve......Argon is heavier than air and sinks.....CO2 floats.....You get a tingling sensation in your nose when CO2 is present. Sort of like sticking your nose over a pop bottle and sniffing. Sure enough......CO2 was there.  I asked him how a brand new tank of gas can have contamination.He told me that even though they vacuum out the tanks, sometimes if it was a 75 /25 tank or a tank that held CO2, the CO2 ice will stick to the side of the tank and contaminate the argon. Any presence of CO2 in the tank will cause exactly what you and I have experienced. They pump out the CO2 and when it moves, it gets cold....the side of the tank gets CO2 ice on the inside. That ice does not pump out and so it stay there till the argon is pumped in and then reverts to a gas. He said that they have gotten quite a few contaminated argon tanks lately. The tanks are contaminated due to poor refill procedures....some folks just don't follow standard operating procedures and that is what happens.
Reply:Pretty good chance that your gas line from torch head to solenoid is contaminated at least a bit.  It should be fairly hard and smooth rubber/plastic, so a good hard purge could clean that up. If you left the green hose from the reg to the machine open on one end or the other that natural rubber can get real bad with absorbed moisture, etc.  The natural rubber can and will let moisture and oxygen right through the wall as well.  Borrow a good green hose and reg and try that.  If it is still bad see if you can borrow a whole new torch and test the torch lines.  A full bottle of N2 will really purge hoses out pretty nice unless they are just too bad
Reply:You have one or more of three problems. Your shielding gas is inadequate, not enough flow, not heavy enough to shield adequately, wind is blowing your gas away. Your high frequency stabilizer is not putting out properly or if you have a points type high frequency stabilizer then the gap is wrong or your points are dirty. Finally you may have a heavy oxide layer on the aluminum. Any one or any combination of these will produce the problems you have described.
Reply:: Originally Posted by KelvinWas it plugged in?Sorry, sounds like you checked everything including the muffler bearings!
Reply:Originally Posted by boatbuoybad gas ?
Reply:Originally Posted by jontheturboguyCan you adjust the ac side on that machine? Maybe you have it set at max.cleaning or max penetration?
Reply:Originally Posted by StevefromOhioI had a very similar problem. I had run out of Argon so I went to the LWS. Got the tank home and tried to weld some aluminum.Problem was the same as yours.....no weld puddle and dirty black soot contamination on aluminum. Steel welds that have a gray look to them. The tank was marked argon. I took the tank back and showed them a test I did. They said that it was CO2 contamination.The manager came by and did a test....he opened the valve a bit and sniffed the gas coming out with his nose above the valve......Argon is heavier than air and sinks.....CO2 floats.....You get a tingling sensation in your nose when CO2 is present. Sort of like sticking your nose over a pop bottle and sniffing. Sure enough......CO2 was there.  I asked him how a brand new tank of gas can have contamination.He told me that even though they vacuum out the tanks, sometimes if it was a 75 /25 tank or a tank that held CO2, the CO2 ice will stick to the side of the tank and contaminate the argon. Any presence of CO2 in the tank will cause exactly what you and I have experienced. They pump out the CO2 and when it moves, it gets cold....the side of the tank gets CO2 ice on the inside. That ice does not pump out and so it stay there till the argon is pumped in and then reverts to a gas. He said that they have gotten quite a few contaminated argon tanks lately. The tanks are contaminated due to poor refill procedures....some folks just don't follow standard operating procedures and that is what happens.
Reply:Originally Posted by Fred sPretty good chance that your gas line from torch head to solenoid is contaminated at least a bit.  It should be fairly hard and smooth rubber/plastic, so a good hard purge could clean that up. If you left the green hose from the reg to the machine open on one end or the other that natural rubber can get real bad with absorbed moisture, etc.  The natural rubber can and will let moisture and oxygen right through the wall as well.  Borrow a good green hose and reg and try that.  If it is still bad see if you can borrow a whole new torch and test the torch lines.  A full bottle of N2 will really purge hoses out pretty nice unless they are just too bad
Reply:Have you tried a different torch on the bad machine?Turn the machine on, open the cylinder and purge the lines with a tap of the pedal.  After the postflow is done, turn the cylinder off.  Watch the gauge for a minute or so and see if you lose pressure or not.Have we all gone mad?
Reply:Originally Posted by Fusion1You have one or more of three problems. Your shielding gas is inadequate, not enough flow, not heavy enough to shield adequately, wind is blowing your gas away. Your high frequency stabilizer is not putting out properly or if you have a points type high frequency stabilizer then the gap is wrong or your points are dirty. Finally you may have a heavy oxide layer on the aluminum. Any one or any combination of these will produce the problems you have described.
Reply:Originally Posted by sn0border88Have you tried a different torch on the bad machine?Turn the machine on, open the cylinder and purge the lines with a tap of the pedal.  After the postflow is done, turn the cylinder off.  Watch the gauge for a minute or so and see if you lose pressure or not.
Reply:can we see some pictures??sure wood hep me lookin Fo a problemidealarc 250/250 ac-dc tigidealarc 250/250 ac-dc tig #2 used for sticklincoln sp100hh125dual arbor grinder polisher30 yrs of hand tools52 pitch blocks 6p-26prake gauge -pitch gaugeG&D prop repair 918-207-6938Hulbert,okla 74441
Reply:Three different bottles. Could be a whole group was contaminated. All it takes is one person who is not paying attention and fills up a whole bunch of 75 /25 tanks but did not purge them correctly to be pure argon.  I would take the tank back and ask the manager to test the contents for CO2.
Reply:Check for a hole in your gas hose, or if it is being obstructed.Check the backcap  to see if you snapped the end off.Crack the backcap just a tad, pull the cup, collet, and tungsten out and look inside to see if the gas port is choked off by the backcap.Lastly, see if your collet is crushed. If it is a cheap chinese collet it will soon crush and block off the gas flow to your weld. My guess also is three bottles bad in succession is rare. I get one maybe every 200 bottles.Good Luck, I hate when that happens.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:I had a similar problem and thought it was a bad tank of argon. Took the full tank back in and got another one and same thing. Come to find out there was condensation in my regulator messing it up. After taking it apart and cleaning it perfectly everything is back to normal. No idea how it got in there.
Reply:need some of these. Attached Images
Reply:Originally Posted by StevefromOhioThree different bottles. Could be a whole group was contaminated. All it takes is one person who is not paying attention and fills up a whole bunch of 75 /25 tanks but did not purge them correctly to be pure argon.  I would take the tank back and ask the manager to test the contents for CO2.
Reply:Originally Posted by shovelonCheck for a hole in your gas hose, or if it is being obstructed.Check the backcap  to see if you snapped the end off.Crack the backcap just a tad, pull the cup, collet, and tungsten out and look inside to see if the gas port is choked off by the backcap.Lastly, see if your collet is crushed. If it is a cheap chinese collet it will soon crush and block off the gas flow to your weld. My guess also is three bottles bad in succession is rare. I get one maybe every 200 bottles.Good Luck, I hate when that happens.
Reply:Originally Posted by VPTI had a similar problem and thought it was a bad tank of argon. Took the full tank back in and got another one and same thing. Come to find out there was condensation in my regulator messing it up. After taking it apart and cleaning it perfectly everything is back to normal. No idea how it got in there.
Reply:Originally Posted by prop-doctorcan we see some pictures??sure wood hep me lookin Fo a problem
Reply:Originally Posted by Vinnieneed some of these.It was a bad bottle of gas.  It was the third bad bottle of gas.  So for me four is the charm.Thanks to everybody for all the help!!Roy