GTAW: All About Porosity

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Hi fellas...After i finished my training in TIG welding i just bought a TIG/SMAW 200 inverter and i just prepared a small workshop for myself in the backyard. To be honest i'm good at TIG Welding and although i just learned it 2 months ago i already have my 6G Certificate in Carbon Steels.Now, my problem is POROSITY. i just anticipated all the trouble-makers and eliminated them but it seems they don't wanna leave me. my welding condition:1) outdoor, but closed and restricted by thick curtains.2) Carbon Steels.3) Standard 200 amp TIG/SMAW4) Standard 20 litre capacity  Argon cylinder and related attachments.Note: It's not because of the wrong angle of the torch or a long arc.        It's not because of a high current that causes burning of the base metal.        It's not because of the ARGON FLOW. I just tried almost all kinda flows   (from 2.5 up-to 15 CFH (i have turbulance in my puddle by 10 cfh and higher than that))        It's not because of the rusty, dirty base metal. all the surface is ground.        It's not because of an impure tungsten. ( %1 thoriated tungsten)        It's not because of the FILLER METAL. as you can see in the photo i have porosity FROM THE VERY BEGINNING. when i tried to heat up the base metal to add the filler later, i have porosity.i'm fed up with this. i just wasted lot's of my materials and i can't get rid of them.my guess is ARGON IMPURITY.(and the circular spots in the photo are not arc strikes. they are the different starts that i did to make sure that i have porosity from the beginning without adding any filler metal.)Any other ideas are appreciated.thanks... Attached Images
Reply:You have bad gas or gas flow issue.Make sure the flow rate is correct. Too much or too little can be a problem.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:Could it be dirty fingers/gloves touch the filler rod? Or a chemical contamination of the base that grinding did not remove? Also be mindful of where your sweat may be dripping. Being outdoors can be tricky, even with the best wind guards.Last edited by Standup Philosopher; 09-12-2012 at 12:27 PM.MM211Rigid chopsawDelta Drill Press
Reply:Originally Posted by Standup PhilosopherCould it be dirty fingers/gloves touch the filler rod? Or a chemical contamination of the base that grinding did not remove? Also be mindful of where your sweat may be dripping. Being outdoors can be tricky, even with the best wind guards.
Reply:I had similar problem. I tried everything, even replacing regulator. At the end I found out, that plastic tube for argon that comes from regulator had a little hole in it. It was sucking air and contaminating my argon. Good way to find out if your shielding gas is good --> Take a piece of stainless steel, then make a short weld on it (like tack weld), also put your postflow to max. The weld must be perfectly silver, if it's not you have problems with shielding gas.
Reply:What about the settings on the welder? The brown soot seems to indicate an impurity of some kind. Was the metal galvanized?Ian TannerKawasaki KX450 and many other fine tools
Reply:Is the parent metal clean?  Really, really clean? Practically sterile clean?Try washing with acetone and NEW SS wire brush, cap the acetone and set aside, far aside, then weld again.  See if there is any improvement.  If no then move on to the next possible cause. - MondoMember, AWSLincoln ProMIG 140Lincoln AC TombstoneCraftsman Lathe 12 x 24 c1935Atlas MFC Horizontal MillCraftsman Commercial Lathe 12 x 36 c1970- - - I'll just keep on keepin' on.
Reply:It's a matter of "elimination". To certify that you have a 100% pure argon flow coming out of the torch here's what you will need to do.Turn the welder OFFTurn your Argon flow ONTake a baggie (or a balloon or even a condom) and use a rubber band to secure it to the ceramic cup ONLY.Punch a very, very small hole in the baggie / condom. Set enough flow to where it keeps it tightly inflated.Put a mixture of Dawn dish washing soap in a spray bottle. (1 teaspoon to a pint of water).Lay your TIG torch out straight or suspended.Begin at the connection where the regulator attaches to the bottle and spray it down.Move along the line until you get to the cup and finally spray the cup itself.Look close where the cup contacts the torch body (washer) and where the cap fits over the tungsten (O ring).Go back over it and continue to inspect. Then begin to twist, roll and flex the hose as you continue to spray it down.Report back as to what you find.Thanks,Hobo.Lincoln SA200's... at least 15 - 20. They come and go. Growing partial to the "Short Hoods" in my old age. Last count on Short Hoods was 13 in possession.
Reply:hi.thanks for all of those useful tips guys.i just did it on stainless steel and i still had the problem, although all the equipments are recently bought, i tried to check the hose and regulator for any gas leak and of course there wasn't any. but then a stupid idea came into my mind about a switch on my inverter. It changes the process for SMAW or TIG welding. so LOGICALLY it should be on TIG when you are tig welding so hopelessly i just switched it on SMAW. and it just worked out!! there is no HISS sound (like base metal burning) at the beginning of the welding and subsequent porosity. I am just sad that a reckless, stupid manufacturing of a machine wasted my time and my materials for so long.Anyways... Thanks a million for the Tips. i just learned a lot....
Reply:Hi, which model and which brand is it?  Try to avoid it.
Reply:Originally Posted by R00kiehi.thanks for all of those useful tips guys.i just did it on stainless steel and i still had the problem, although all the equipments are recently bought, i tried to check the hose and regulator for any gas leak and of course there wasn't any. but then a stupid idea came into my mind about a switch on my inverter. It changes the process for SMAW or TIG welding. so LOGICALLY it should be on TIG when you are tig welding so hopelessly i just switched it on SMAW. and it just worked out!! there is no HISS sound (like base metal burning) at the beginning of the welding and subsequent porosity. I am just sad that a reckless, stupid manufacturing of a machine wasted my time and my materials for so long.Anyways... Thanks a million for the Tips. i just learned a lot....
Reply:Originally Posted by shovelonThat's pretty good welderin' for no gas tig. Maybe you should patent your process.