Strange issue with aluminum tig..

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I've been tigging aluminum for awhile now, and have just run into this issue and can't for the life of me figure it out. Basically I have a severe contamination issue. Doesn't matter how much I clean the metal.. SS wire brush acetone, brand new shiny aluminum.. Clean sharp tungsten.. As soon as I start the arc you can see the black crap and as soon as you add rod it turns even more to crap. The beads also tend to crater down and flatten out like its too hot, but doesn't matter how much you back off. The machine is a diversion 180 I've tried different tungstens but mainly using ceriated.. tried all different flow rates from 10 all the way to 30 and nothing changes. Tried all different cups from a number 6 to a #7 medium gas lense... Nothing changes.. tried different filler and cleaned the rod, different peices of aluminum. No difference. I even tried a different bottle and got the same results. I went and ran some beads with my Bobcat and HF 251.. and they came out absolutley fine.. go figure. This diversion is about 2 weeks old.. at first I ran some really nice aluminum beads with it and was really pleased.. then the next day It just won't work..  Could there be something wrong with the machine? I know these machines have a preset AC balance.. could something have gone out of whack with this??   I have no idea where to look.. Any input is really appreciated..
Reply:Gas.Check and see if you have a crushed collet, hole in gas line, loose fittings, broken back cap.These are the first things I check for, and usually are the culprit.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:Originally Posted by shovelonGas.Check and see if you have a crushed collet, hole in gas line, loose fittings, broken back cap.These are the first things I check for, and usually are the culprit.
Reply:if works with other rig  i would agree leak or plug some whereidealarc 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:Well I tried another collet and back cap that worked fine with another torch just a minute before the swap.. no change however, same problem. Then I found a leak at the regulator to bottle connection I tightened the reg and checked the entire hose for leaks with soapy water.. I even checked the connection inside the torch body ..everything looks good but still won't weld right.. I have had the bottle valve off for about a half hour now and the gauges haven't moved... which leads me to believe that what ever the problem is its after the solenoid...?     Both the collets I have aren't in great shape.. but even the one thats a little worse works fine on my other torch and set up..  Neither of them made any difference in the ls 17 torch on the diversion.. Could the collet really be the issue? I'll grab a few new ones tomorrow either way.. This machine is only 2 weeks old..
Reply:Black is contamination. Can you turn the cleaning up?  Torch pointed towards the finish line?  I weld aluminum at 25 to 35 cfh pure argon and sometimes a gas lens 1/2" cup.  (#8).CLEAN UNCONTAMINATED  tungsten?I had some old rod that put contamination in the clean puddle.  As soon as the rod was dipped, the puddle went south.  It had to be 20 years old.  What if you pass the torch over the joint with no filler?DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:Can you hear the gas coming out of the torch after you press the pedal?Put it up to your ear and have a listen..SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSssIs what you should hear......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:Don't let the hi freq zap your ear Real world weldin.  When I grow up I want to be a tig weldor.
Reply:There's definitely gas coming out.. you can hear/feel it.. When i was checking for leaks i even took the tungsten out and held my thumb partially over the cup to build a little pressure to be sure there were no leaks in the torch hose... tungsten is clean.. filler rod is clean and new.. material is clean and new.. No cleaning adjustment on the Diversion.. its all pre set. It's definitely got me confused. One day it was laying the nicest aluminum beads ever.. next day black blobs.
Reply:Dumb question..Did you accidently take it out of AC and now it's on DC?That's about all I can come up with.....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:Bad Gas... try another bottle.Rick V 1 Airco Heliwelder 3A/DDR3 CTC 70/90 amp Stick/Tig Inverters in Parallel1 Lincoln MIG PAK 151 Oxy-Acet
Reply:Nah its on AC.. I spent 4 hours today trying to get this thing to weld.. Honestly, I wish it was me making a dumb mistake..  I'll mess with it some more tomorrow ..  Thanks for all the input so far..
Reply:Originally Posted by Rick VBad Gas... try another bottle.
Reply:Except for the fact that you said it worked fine at first, it sounds to me like the lines were never purged of air. Any chance that water has somehow gotten into the gas line and enough vapor is mixed with the argon to react with the aluminum? How does it weld on steel or copper alloys?If the gas emerging from the nozzle is pure argon, then the only other cause of your problem I can think of is that something in the front of the torch is causing the gas to squirt out, as from a jet, rather than coming out in a slow and uniform manner all around the center of the tungsten. I'd open the front up, (remove all parts) and take a close look inside; perhaps run some gas through that way to see/hear if anything unusual happens.Have any Goblin smoke to run through, so you can see the pattern better?   Think I hear some Goblins next door, right now....
Reply:Try stripping all the parts out of the torch head and screw a back cap into both the front and rear. The o-rings should seal both places. Then leak check the torch head, including inside the handle. Make sure the collet is screwed all the way in on reassambly. Definitely a head scratcher here....
Reply:Originally Posted by mrusso   Both the collets I have aren't in great shape.. but even the one thats a little worse works fine on my other torch and set up..  Neither of them made any difference in the ls 17 torch on the diversion.. Could the collet really be the issue? I'll grab a few new ones tomorrow either way.. This machine is only 2 weeks old..
Reply:So I figure I'll let everyone know what the outcome was.. It was in fact bad gas... I had two contaminated bottles. I had them swapped and ended up with one good one and another bad one.. frustrating as hell. They're all from the same batch that just come back from hydro test so they either have residual water in them or previously had some c02 in them which apparently embeds itself in the cylinder walls...? I was told once a cylinder has C02 in it it will never be good for pure argon again.. The hydrotest company just pulls the lables off and throws them all in together..   oh well.. maybe I'll get lucky tomorrow.
Reply:Oh Rick gets a brownie pin for the bad gas ideaTiger Sales:  AHP Distributor    www.tigersalesco.comAHP200x; AHP 160ST; MM350P,  Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma.  For Sale:  Cobra Mig 250 w/ Push-pull gun.  Lincoln Wirematic 250
Reply:did it look like this at all?
Reply:Originally Posted by soutthpawOh Rick gets a brownie pin for the bad gas idea
Reply:Originally Posted by mrussoSo I figure I'll let everyone know what the outcome was.. It was in fact bad gas... I had two contaminated bottles. I had them swapped and ended up with one good one and another bad one.. frustrating as hell. They're all from the same batch that just come back from hydro test so they either have residual water in them or previously had some c02 in them which apparently embeds itself in the cylinder walls...? I was told once a cylinder has C02 in it it will never be good for pure argon again.. The hydrotest company just pulls the lables off and throws them all in together..   oh well.. maybe I'll get lucky tomorrow.
Reply:Not long ago I thought I got a bad tank of gas as well. Turned out there was moister in my regulator... Not sure if the tank had the moister in it or if somehow the moister got in the regulator while it was off the bottle while I was out getting an exchange.The low pressure gauge was jumping a little while flowing gas. That is what made me tear it down.
Reply:Originally Posted by MoonRiseNah, unless you are down to the microscopic level, CO2 does NOT "embed" itself in the tank walls.If the fill company does not completely purge and/or pull a hard vacuum on a 'mixed gas' tank and then just goes and puts that tank into service as an 'argon' tank, then you WILL most likely just have some residual 'mixed gas' left in the tank/cylinder instead of pure argon.Which is just a screw-up big time on their part.And if they are also filling 'medical' cylinders the same way, then they could end up not just causing some 'bad' welds but could cause someone's death.Ahh, hydrotest, hmmm?  Yeah, if they didn't clean, dry, and pull a hard vacuum on the tanks/cylinders after the tanks/cylinders were filled with water for the hydrotest then those cylinders were indeed contaminated with water/water-vapor.Sounds like it's time for some QC overhauls at that place, eh.Thanks for posting the follow-up.
Reply:Originally Posted by Freestyle72did it look like this at all?
Reply:I just experienced a very similar issue with my first bottle of argon.My steel beads kept showing a lot of porosity, and aluminum ended up having black soot and the beads were not shiny, but kind of rough-looking.After reading a post here about contaminated gas, I went and exchanged my bottle, and viola!  Nice solid steel welds, and smooth shiny aluminum beads.  I don't know exactly what the contaminant may have been.