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  • Porous Tig welds!

    Hey Guys, Im new to the forum and not so new to welding.

    I tried searching but nothing has helped me so far.

    Now Ive been tig welding for about two years now, 90% of my welding has been stainless and stainless to mild steel, basically everything from 18g to 1/2". I have not had a single problem what so ever!

    Im now having a problem welding just mild steel with my tig welder, for some reason the pool bubbles and blows out causing tiny holes throughout the bead. Now it doesn't happen all the time either. I could be welding for a few inches then all **** brakes loose for the rest of the weld. My project is a triangulated 4-link, crossmembers and rear coils for my TT 600hp 306 Explorer. I just finished welding the 10 axle tabs last night with minimal problems, in two spots as I got to the end of the tab I got a few pin holes, but nothing to worry about. Tonight I tried welding the crossmember with very little success, no matter what I do the weld blows out, pops, etc.

    I have a DC-Inverter from Ebay, its a CAT-518D.
    Im using Power Weld 2% Thoriated 3/32" tungstens
    My flow meter is usually set between 5-10, however it seems to be different from most Ive seen, it goes from 1-25 but is rated in e/min. On the side of the meter it says 2.0 degrees Celsius, 0.15MPA. Ive been using 5-10 forever now and it seems to be right on the money. I tried increasing it to about 15 and it helped a little bit with pin holes but not 100%. It sounds like a blower attachment for a compressor at 15 though!

    As far as grinding tungstens, Ive been using a grinder with an old wheel on it since I started tig welding. Just recently I but a resurfacing tool to clean it up but it hasnt helped with the mild steel welds. I use dedicated brushes for prepping the metal as well. Im pretty much at a standstill until I can figure this out. Its really fustrating when you need to get something done. If anyone needs more info feel free to ask. Thanks for any and all help!

  • #2
    sounds like gas flow problem,5 to 10 seems a little low also try changing ur cup, might be contamination from that or are you welding steel that has been in sevice before? some times i have found oil and other contaminates in the steel, heating with a torch can pull them out of the steel then clean them off with a grease less solvent. also had problems before with dirty filler rod
    Last edited by arc; 06-17-2008, 06:50 PM.
    trail blazer 302
    hypertherm plasma
    millermatic 251
    high feq. arc starter
    suit case (extreme 12vs)
    o/a torches
    way to many other tools to list

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    • #3
      Gas flow

      I don't know your thickness, but 5-10psi is way too low. 15-20 is what you need. Are you having problems on the SS or the mild steel? What kind of SS are you using? Are you using red tungsten? I did a sloppy job, but not crucial, on a drip tray that was't visable. The material wasn't the same alloy as my rod.
      Millermatic 210
      Syncrowave 200
      Spectrum 625 X-treme
      Hobart Champion 16 W/
      Miller 8VS Suitcase
      Miller 3035 Spool Gun
      Tons of Tools
      Microwave
      Laptop and Printer
      Speakers in the Back for all to hear Sirius Radio!

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      • #4
        Try another bottle of argon...
        Professional Auto Mechanic since 1974
        My own shop since 1981
        Cya Frank

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        • #5
          Sounds like intermittent joint contamination from what you're describing. Are you cleaning the joints with acetone prior to welding?
          Syncrowave 250DX
          Invison 354MP
          XR Control and 30A

          Airco MED20 feeder
          Thermal Dynamics Cutmaster 81
          Smith O/A rig
          And more machinery than you can shake a 7018 rod at

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          • #6
            I tried upping the gas flow but its really doesnt change anything in this situation. The truck is a 97, the frame had the original coating plus its been oil sprayed. Prior to welding I just ground down to fresh metal with a 2" disk. I think over the years the oil soaked into the metal and its coming out when I weld. I like the idea of heating and cleaning with a solvent, that makes total sense. Also all my tabs and crossmembers came oil treated so they don't rust, again all I did was grind down to fresh metal.

            Right now Im welding 1/4" to 1/4" and 1/4" to 3/16" mild steel. Ive never had a problem with any stainless or stainless to mild steel before. All of my turbo flanges were cut with a torch and then cleaned up so i assume from the heat all the contaminants were removed from the metal. Also Im using red tungsten.

            The current bottle of argon is new and it did this with the bottle prior.

            I think im going to heat and then clean with acetone. Thanks for the quick replies and I'll let you guys know how goes in the next few days!

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            • #7
              turn you amperage down 5 to 10%. If you are running on the same settings as the stainless steel. It doesn't need that much energy. Try it on some scrap to tune in the settings.

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              • #8
                Originally posted by lanceman73 View Post
                I don't know your thickness, but 5-10psi is way too low. 15-20 is what you need. Are you having problems on the SS or the mild steel? What kind of SS are you using? Are you using red tungsten? I did a sloppy job, but not crucial, on a drip tray that was't visable. The material wasn't the same alloy as my rod.
                Actually, most of the flowmeters for GTAW are pre-set at 15 psi. It is the flow that is adustable, not the pressure. The flow is usually calibrated in cfh.

                I do not know what this poster's meter calibration refers to (e/min).



                Griff

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                • #9
                  check everything

                  Turbo, other things to think about are that this could be from the wire that your using. I have had tig wire make porosity due to manufacturing problems. Use another wire from a different batch, and test it with a small bead on the same metal, then grind the top off to check for holes.
                  The base metal should be heated like Arc said, to rid it of anything that has penetradied it over time, then clean with some greaseless cleaner.
                  Make sure you gas lens is clean, old ones will cause porosity. Buy a new one if you have any doubts.
                  You have ruled out the argon, but take your tig rig, ( make sure it's not connected to the power) and insert the whole thing into a 5 gal bucket filled with water. I have had small pinholes in the tig head/body/insulator/tail, and hose, give me fits with porosity. Make sure and do your argon hose too. Temp fix if it does have holes is to tape with rubber splicing tape 2 layers thick, then electrical tape 2-3 layers thick over that. This won't get you a X-ray quality weld, but should get the weld finished.
                  Personally, I never weld with less than 20 cfm on the flowmeter, but I don't pay for the gas either. All the hose/flowmeter connections should be checked with some kind of soapy water too.
                  Worst case, is that the base metal is just no good, anything you do won't help usally. Try a different filler wire, sometimes i've used ER316/ER308/ER309 for the 1st pass, very thin layer, then come back with the carbon wire on top, cuts down the porosity enough to finish the weld.

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                  • #10
                    Fine, this thread is 12 years old. Some of you could be dead by now. Still, there is another culprit that hasn't been mentioned that I thought I'd add for posterity:

                    I had the same exact problem (intermittent extreme porosity on mild steel) and read this entire thread to find what else I could try. I tried absolutely everything mentioned including the extreme steps of submerging my torch head and hose in a 5-gallon bucket of water to find the leak. (BTW, if you do this, take your consumables out of the torch and seal it by using end caps in the FRONT as well as the back.) I changed virtually every part involved except the welder itself. I even took the cover off (Syncrowave 250). I also have 2 argon cylinders, and switching to the other proved no help.

                    I would get the porosity, change something I thought was the culprit, lay a bead on some scrap until I was satisfied the problem was gone, then continue with my project, only to have the problem return at the most inopportune time. This cycle repeated several times.

                    Finally, the culprit? : A fricking no-name (probably Chinese) floating-ball regulator I got from Amazon. Once I switched it out and put back the dial regulator that came with my Dynasty package some 20 years ago, the problem disappeared for good. If I was a pro welder and welded frequently, it probably would have dawned on me immediately, but I got and installed this Chinese reg about 6 months ago. Come to think of it, I had a terrible time with my last aluminum project, which I just chalked up to lack of cleanliness and skill, but I remember aluminum being much easier, and now I find out it was the reg.

                    The Chinese regulator is now scrap brass and I've ordered a proper Harris floating ball regulator from CyberWeld.

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                    • #11
                      Originally posted by gaaah View Post


                      The Chinese regulator is now scrap brass and I've ordered a proper Harris floating ball regulator from CyberWeld.
                      Should have bought a Smith regulator. They are about the last USA made...Bob
                      Bob Wright

                      Spool Gun conversion. How To Do It. Below.
                      http://www.millerwelds.com/resources...php?albumid=48

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                      • #12
                        Originally posted by aametalmaster View Post

                        Should have bought a Smith regulator. They are about the last USA made...Bob
                        You're probably right. This afternoon I made it a point to see what brand that old Miller reg was that saved the day: Smith.

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                        • #13
                          Smith and Miller are Sister companies owned by ITW. Smith regs have been with new Millers for quite awhile...Bob
                          Bob Wright

                          Spool Gun conversion. How To Do It. Below.
                          http://www.millerwelds.com/resources...php?albumid=48

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                          • #14
                            Did you at least smash the old with a BFH just to get a little retribution?

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                            • #15
                              Originally posted by ryanjones2150 View Post
                              Did you at least smash the old with a BFH just to get a little retribution?
                              Even worse: I'll be doing an autopsy on it while it's still alive.
                              Last edited by gaaah; 02-19-2020, 10:30 AM.

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