Tig Problems - Porosity and arc start

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Hey guys,Been having a couple problems with my tig welding that I've been trying to figure out for the past few weeks.  I'll start by saying that I'm a self-taught hobbyist and I've been working with the tig for around 6 months or so.  If it matters at all, I have an HTP 221H.Initially, I wasn't experiencing any problems - but in the last couple projects I've worked on, I've experienced intermittent weld porosity and arc wander / start up problems on arc initiation.  Let me explain a little bit:On one project, I was welding up some (well prepped) mild steel DOM A513 (1018) steel tubing with ER70S-6 filler.  Once the tubes were cut, I deburred them all, wire wheeled off the mill scale, and then thoroughly wiped with acetone and isopropyl alcohol and allowed that to air dry.  I used a 2% lanthanated 1/16" tungsten with a #7 gas lens and ~ 30 CFH in a calm environment, and I wiped my filler rods with acetone before using.  I also keep them stored in tubes with some dessicant packs so there's no corrosion on them.  When welding, certain sections of the joint would burn in really nice, and others would outgas as though I was running over oil or something...the puddle would erupt like a volcano.  Initially I thought it was a material and/or prep problem, but I've had two different shipments of tubing and various other pieces of practice scrap that all have this issue.  I even experimented with making my cuts with the IPA as a lubricant instead of oil to leave no chance for residual contamination, but nothing has worked yet.Then over the past few weeks, I've started developing low start problems - I can hear the HF working but the arc doesn't jump off the tip of the tungsten cleanly.  I have a good ground, the tungsten is sharpened to a point and the sharpening marks are oriented along its length.  Thinking I might have an internal short in the torch, I've tried changing out collets, collet bodies, cups, tungstens with new replacements and nothing has resolved the issue.I had my friend who is a weldor by trade come over to look at it, and he couldn't seem to figure out what the issue was either.  We tried a bunch of different torch configurations, different settings, different flow rates on the gas, etc. and nothing resolved it.Sorry for the long post, I'm just not really sure where to go from here in my troubleshooting.  Any suggestions / insight are greatly appreciated.Thanks,Chuck
Reply:If you have porosity there is a shielding problem or contamination.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:It seems like you've done everything you can do ensure a nice, clean TIG weld. You describe a textbook weld. Perhaps you could post some pics of the problem welds and I'm sure one of the more experienced welders here will chime in and tell you exactly what the issue is.HTP Invertig 221Hypertherm Powermax30 XPPlus other stuff
Reply:I'll have to get some pictures of the porous welds, I don't have many on hand at the moment.  You can kind of see it happening here at the right edge of the bead.  it's gotten worse since this pictureThis is how it was welding before, but I haven't been able to get it to weld like this since then.  this is the same dom tubing with 1045 end caps that I turnedThis is an overall view of the project I mentioned, subframe brace for my car.  I drilled small vent holes in the tube to be enclosed to prevent gases from blowing out the weld when it wrapped the whole way around.  Pretty tight fit up everywhere.  Just really at a loss at what is going on.Last edited by ckpitt55; 10-31-2014 at 10:11 AM.
Reply:Could be a couple of things...The INSIDE of the tube must be as clean as the outside as far as you can get it...Oil/Crud LOVE heat!It acts like a wick and travels to the heat source in record time..Gas..Are you actually hearing it when you step on the pedal?Put your set up torch near your ear and listen.Could also be a kink in your gas line somewhere that is getting pinched off as you manipulate the torch..Not got the chair/stool leg on top of your lines do ya?All the above has been the culprit at one time or another.....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:YOU ARE RUNNING 30CFH THROUGH A #7 CUP!       YOU ARE PROBABLY SURGING AT OVER 50CFH sucking air into the weld on start!  Try lowering to 15 - 18cfh and see what happens. Too much gas is as worse than too little. At least you will be conserving money at too little.And snip your wire end before using again. Or keep your rod under the gas during post flow.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:You might want to buy one of these and check your surge on start.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 zapsterCould be a couple of things...The INSIDE of the tube must be as clean as the outside as far as you can get it...Oil/Crud LOVE heat!It acts like a wick and travels to the heat source in record time..Gas..Are you actually hearing it when you step on the pedal?Put your set up torch near your ear and listen.Could also be a kink in your gas line somewhere that is getting pinched off as you manipulate the torch..Not got the chair/stool leg on top of your lines do ya?All the above has been the culprit at one time or another.....zap!
Reply:Have you had a friend watch your flow on the gauge as you weld? Perhaps its time to lay a big piece of steel down and just run stringers/beads on it. It may even be a regulator or internal solenoid issue.
Reply:Originally Posted by turismolover22Have you had a friend watch your flow on the gauge as you weld? Perhaps its time to lay a big piece of steel down and just run stringers/beads on it. It may even be a regulator or internal solenoid issue.
Reply:You could also try tungsten stickout 1/2 to 3/4 the diameter of the cup orifice. Keep your torch angle as vertical as possible. Check your gas lens to see if it is not clogged, as clogging one side messes the whole enchilada.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:How much gas is left in the bottle? Do you have another bottle to check for bad gas?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 shovelonYou could also try tungsten stickout 1/2 to 3/4 the diameter of the cup orifice. Keep your torch angle as vertical as possible. Check your gas lens to see if it is not clogged, as clogging one side messes the whole enchilada.
Reply:Crap from GO!!!!!...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:Is this an air-cooled torch with a one-piece power cable?  If the cable gets hot, it can melt the hose and allow air to be drawn in.  Remove the tungsten, block the end of the cup with something non-conductive and hit the pedal long enough to start the gas.  Check for leaks during post flow.  If there are no leaks, then get a clean piece of aluminum and switch to AC.  Hold the torch vertically and create a puddle . . . no filler.  Shut the current off abruptly.  The cooled puddle should be shiny with a frosted ring around it.  If not, you have a gas coverage or contamination problem.Dynasty 300DXSmith He/Ar gas mixerMM350PHobart Handler 120Smith LW7, MW5, AW1A
Reply:Originally Posted by ckpitt55I tried replacing the gas lens with a brand new one...does the same thing.Regulator is showing ~500 psi left in the tank, I have another bottle but it's C25 for my mig - assuming I can't use that because of the c02 component.  I'm not 100% certain of the time line but I think my problems might have started around the same time I got a new fill.  Maybe it's the gas?What would the weld look like if they gave me c25 instead of 100% argon?
Reply:Originally Posted by 4sfedIs this an air-cooled torch with a one-piece power cable?  If the cable gets hot, it can melt the hose and allow air to be drawn in.  Remove the tungsten, block the end of the cup with something non-conductive and hit the pedal long enough to start the gas.  Check for leaks during post flow.  If there are no leaks, then get a clean piece of aluminum and switch to AC.  Hold the torch vertically and create a puddle . . . no filler.  Shut the current off abruptly.  The cooled puddle should be shiny with a frosted ring around it.  If not, you have a gas coverage or contamination problem.
Reply:Change the gas lens, cup, collet, back cap oring, and grind a fresh tungsten on a non-contaminated surface. My Dynasty did this the other day to me.....Miller Dynasty 200DXMiller Spectrum 250DMiller Millermatic 200Bunch of old blue dinosaurs....
Reply:Btw its a dirt/gas problem.  Look at the second pic...you still have black soot all over the place.Miller Dynasty 200DXMiller Spectrum 250DMiller Millermatic 200Bunch of old blue dinosaurs....
Reply:Originally Posted by jontheturboguyBtw its a dirt/gas problem.  Look at the second pic...you still have black soot all over the place.
Reply:ckpitt55,How sure are you that the end cap is actually 1045?   I've had porosity that looked just like what you're getting in the first picture in post 17 before when a batch of the plugs I was welding into hydraulic control blocks accidently got made from leaded free machining steel (12L14 IIRC).   Could it be that what you're thinking is 1045 is actually something in the 11xx or 12xx series?   Also recently had a flow meter fail internally and cause it to suck air in and give me gross porosity when dual shield flux core welding.   Like you I went all over my gas system line checking for leaks but couldn't find any.  It really had me stumped for a while because just the week before I was using the exact same equipment with out problem.  Finally noticed that when the gas was flowing the flow-meter was making an unusual, faint, high pitched noise.   Swapped out the flow-meter and the porosity problem went a way.
Reply:I'm just a hobbyist – and I agree that something definitely doesn't look right about the soot in the last pic – but couldn't it be the material itself that is offgassing in the next-to-last pic?It seems like I've seen that same thing in the past, basically it will bubble out, sometimes not until after you stop the arc, and the only way I could get rid of it was by using some S6 or SS filler.I also found that if you avoid getting it too hot, that helps minimize the offgassing of the material...but I never did find an answer to what I was doing wrong (except possibly overcooking it).
Reply:Originally Posted by HT2-4956ckpitt55,How sure are you that the end cap is actually 1045?   I've had porosity that looked just like what you're getting in the first picture in post 17 before when a batch of the plugs I was welding into hydraulic control blocks accidently got made from leaded free machining steel (12L14 IIRC).   Could it be that what you're thinking is 1045 is actually something in the 11xx or 12xx series?   Also recently had a flow meter fail internally and cause it to suck air in and give me gross porosity when dual shield flux core welding.   Like you I went all over my gas system line checking for leaks but couldn't find any.  It really had me stumped for a while because just the week before I was using the exact same equipment with out problem.  Finally noticed that when the gas was flowing the flow-meter was making an unusual, faint, high pitched noise.   Swapped out the flow-meter and the porosity problem went a way.
Reply:Originally Posted by ckpitt55It didn't come with a material cert but I ordered the raw material from Mcmaster - so unless they screwed up my order it is 1045 for sure.  Made the caps myself so it's not like I'm getting them from somewhere else.  It sure doesn't turn like a free machining steel.I really don't think it's any of my torch components - I've changed everything out.  Different collets, cups, collet bodies, diffusers, tungstens....nothing is making a difference.I might try my other regulator and a fresh tank of gas.  I've also read that welding with a 309L filler might help in situations like this....would that be worth trying?
Reply:Originally Posted by HT2-4956Chuck,Are you putting your torch parts together in the correct way?  You need to screw in your collet body (gas lens) all the way until it seats before tightening the back cap.   If you have the back cap on first (and have it screwed in to far) it can keep the collet body from screwing in as far as it needs to.   Once you think you've got the collet body all the way tight, back off the back cap some and see if the collet body won't tighten further.   Better yet just screw the collet body in all the way before you even put the back cap on the torch.   Speaking of the back cap... check the condition of the o-ring on it.   I've seen those get buggered up (or be missing) and have it cause problems.Chuck,Any idea where the tube was made?   I know it's a long shot but if everything else is as it should be it might just be the odd case of poor quality made steel.   I've had porosity problems before on carbon steels that no matter what you do they just want to bubble up.  I've mostly run in to that problem when trying to TIG on thin carbon steel sheet metal.http://www.thefabricator.com/article...elding-processThe only thing I can think of to tell you at this point is to get some scraps of other material and see if you have porosity problems with it.
Reply:Have you pulled the handle back from the torch head and checked the connection where the power lead /gas hose screws on to the torch?   That connection should be snugged up with wrenches.   All the other parts on the torch (collet body, back cap, cup) just get "finger" tightened.
Reply:Wipe the steel down to remove oil. Grind with a stone or flapper wheel to clean steel and try again.  In thinking your wire wheel may be contaminated.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:Originally Posted by HT2-4956Chuck,Any idea where the tube was made?   I know it's a long shot but if everything else is as it should be it might just be the odd case of poor quality made steel.   I've had porosity problems before on carbon steels that no matter what you do they just want to bubble up.  I've mostly run in to that problem when trying to TIG on thin carbon steel sheet metal.http://www.thefabricator.com/article...elding-processThe only thing I can think of to tell you at this point is to get some scraps of other material and see if you have porosity problems with it.
Reply:Netwelding.comReally would be a good idea to rule out gas flow 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:Originally Posted by shovelonNetwelding.comReally would be a good idea to rule out gas flow problem.
Reply:How about the wind conditions in your work area?   If you're trying to do this out side (or near an open door way or window) I can see that being a factor that could interfere with maintaining good shielding gas coverage.     Even closed up inside a building you've got to be careful you don't have a cross breeze (like from the machines cooling fan) blowing across your work area.    Some times it doesn't take much by way of moving air currents to screw up your shielding gas coverage when TIG welding.
Reply:Originally Posted by HT2-4956How about the wind conditions in your work area?   If you're trying to do this out side (or near an open door way or window) I can see that being a factor that could interfere with maintaining good shielding gas coverage.     Even closed up inside a building you've got to be careful you don't have a cross breeze (like from the machines cooling fan) blowing across your work area.    Some times it doesn't take much by way of moving air currents to screw up your shielding gas coverage when TIG welding.
Reply:Originally Posted by ckpitt55How would you resolve a surge issue aside from turning down the gas?  Do you have any experience with their "Gas saver system" kits with Tig?
Reply:Tried a couple more things tonightGoing with the wire wheel contamination idea - I wiped another area of the same steel plate I welded on previously down with acetone, then took a brand new never used before flap disc and got the metal clean, then wiped it off again with acetone.  Then on the torch end - took a brand new collet body, fresh tungsten, a new cup, and ran a couple beads.  Did the exact same thing as previously - black soot around the weld.  Porosity on some welds, others welded ok aside from the soot.After that I tried swapping on the regulator from my mig which has been dead reliable the entire time I've had it - that didn't make a difference either.I'm almost out of gas - so I'm going to get a fresh fill at another supplier before I go any further with my troubleshooting.
Reply:Last time I had that and couldn't find any other problems it turned out to be very small holes in the torch hose. Took a few tries to find them.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:Originally Posted by ckpitt55I'll get one on order today.Just so I'm clear, I compare the torch output to the flowmeter on the tank.  Apart from any initial surge - if I am reading less at the torch than on the tank then I have a leak or an obstruction somewhere, correct?How would you resolve a surge issue aside from turning down the gas?  Do you have any experience with their "Gas saver system" kits with Tig?
Reply:Well gents it looks like after all my troubleshooting, I finally got it resolved.Looks like I had some bad shielding gas.  I took my bottle to get refilled today - had them blow down the remainder of the contents and then fill it back up.  Got it home and tried it out on that same steel plate and some of the same tubing that was giving me fits - both pieces welded up like they should even with minimal prep - no soot, no porosity, smooth stable arc.....it was beautiful.  I was almost doing cartwheels around the garage hahaThanks to all who stuck with me through this and offered suggestions, I appreciate the help...just figured I'd pop back in and let you all know what the problem was.-Chuck
Reply:Chuck,Glad you got it figured out and that it came down to some thing as simple as "bad gas".