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Bubbling TIG puddle welding AL6061

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  • Bubbling TIG puddle welding AL6061

    I am confused!!!

    I have TIG welded AL for years and have prolly 60 plus hours on my Dynasty 200 with no problems. I am currently welding 2"x3"x0.120" wall 6061 rectangle tubing making a trailer frame. I can't even place a tack without having the puddle suddenly boil up like water. I don't even add filler rod and this happens. I can lay a bead of weld but I know the air pockets are still there. My only thought is that the material was soaking wet when it was delivered but it has sat in the shop for 4 days now. I have welded AL before that has been in the rain and never experienced this. I am using a new bottle of argon, however I have made several welds yesterday on some AL flat bar and channel without this problem. The Tungstens have been stored properly and are maybe 3 months old. I have checked the flow meter and the torch for accurate flow of shielding gas and everything seems fine. I even turned it from 30 to 35 with no success. I have checked for drafts in the shop, changed positions and the probem is still there. I was told by a welding inspector once that air pockets are common in 6061 welding but this is more like an Areo chocolate bar. I can't see how this would be a sound weld. I have the freq set at 150 and balance at 70%.

    Could it be moisture (hydrogen) in the Aluminum?

    Should I try preheat to clear out any hydrogen?
    (I am trying to avoid any preheat on this job because of the weight carrying capacity of the frame and warpage. I would like to keep the HAZ to a minimum.)

    Of course this has to happen on a saturday morning when everyone is closed.

    Thanks in advance on any help.

    -B-
    Midland Welding & Fabrication LTD.

    Miller Dynasty 200 DX
    Miller Trailblazer 302
    Hypertherm 380 Plasma
    Air Liquide M200 MIG

  • #2
    Sounds like You have covered the bases pretty well troubleshooting this. Can You try duplicating yesterdays welds?ie material, argon etc.? if so does it act differently now? I would keep backing up till something You change gets You back to where the welds were good, this way You at least have the problem narrowed down hopefully to one item such as the material or the bottle (My two main suspects).
    Hope this helps You find the culprit. Carl

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    • #3
      brisland,

      If you preheat, use a heat gun rather than a torch. Perhaps prepping with an etching acid like Alumiclean will help. 30CFH seems like a high flow rate for argon. I typically use 12-17 CFH.

      Comment


      • #4
        Thanks guys for the tips...I welded some 2x1x0.120 6063 channel a few minutes ago to the 2x3x0.120 6061 tubing and it seems better...I will drop the flow rate down too...I noticed the reg (gauge style) says 37-38 at idle and then when I hit the trigger it drops to 30...both the flow gauge and bottle pressure gauge never moved from yesterday after turning the bottle off...it usually drops down...maybe the reg is buggered???I usually use a propane hand torch to pre heat but I will try a hair dryer...I used to have a heat gun some where but can't find it..typical..

        Thanks again..

        -B-
        Midland Welding & Fabrication LTD.

        Miller Dynasty 200 DX
        Miller Trailblazer 302
        Hypertherm 380 Plasma
        Air Liquide M200 MIG

        Comment


        • #5
          Can you run a bead in the middle of the piece somewhere to possibly eliminate some kind of contamination on the cut edge of the tube as the problem? Jeff
          200DX 350P 625 Plasma & other stuff I forgot

          Comment


          • #6
            I completely cleaned the cold cut saw before using it with Brakekleen...I have even tried cutting a piece with a different saw....even the mill end of the tube gives me grief...after turning the Dynasty to 'pulse' it seems to be better...however the end of tungsten after a few beads goes gold in color...I have never seen that before either...

            I am puzzled to say the least...the weld bead looks decent to the naked eye...my only concern is that it may crack due to possible air pockets I cant see inside the weld...it happens about 1/4" behind the puddle where the bead is freezing...you can see a bubble trying to poke through...its only one bubble at a time but consistant...I will try to get a hold of some 'Alumiclean' like Hawk suggested tomorrow...

            -B-
            Midland Welding & Fabrication LTD.

            Miller Dynasty 200 DX
            Miller Trailblazer 302
            Hypertherm 380 Plasma
            Air Liquide M200 MIG

            Comment


            • #7
              Plasma Cutter

              Hi Brisland, I was just curious.......... what do you think of your HYPERTHERM? Is it not like cutting butter with a knife? I love them.
              : I sell Miller, still just a girl learning to "use" Miller. Thanks for your patience!!

              Comment


              • #8
                Originally posted by BHeadinOut
                Hi Brisland, I was just curious.......... what do you think of your HYPERTHERM? Is it not like cutting butter with a knife? I love them.
                My first plasma was a Thermal Dynamics in 2001. Absolute garbage. So bad that the supplier allowed a full refund on it 3 months later. I then owned both a Lincoln Prot Cut 55 and Pro Cut 80. I went through consumables like crazy with both machines. The quality of the cut from my new Hypertherm walks all over the red units. I think I get about 3 times the life out of the consumables now compared to the Lincolns. I wish my local supplier had a Hypertherm years ago. Sucks to live on an Island.

                -B-
                Midland Welding & Fabrication LTD.

                Miller Dynasty 200 DX
                Miller Trailblazer 302
                Hypertherm 380 Plasma
                Air Liquide M200 MIG

                Comment


                • #9
                  UPDATE!!!!

                  I welded a headache rack yesterday with 6061 1-1/2"x1-1/2" x 1/8" tubing and some 6063 2x1x1/8" Channel and never had a problem with any bubbles. I went back and welded the 2x3 tubing and again got bubbles. There must be some type of coating on the 6061 2x3x0.120 I got. Never experienced this before and I am actually quite ticked off as I have several trailers to build and want to remedy this problem. Has anyone ever worked with 'new' contaminated AL tubing????

                  -B-
                  Midland Welding & Fabrication LTD.

                  Miller Dynasty 200 DX
                  Miller Trailblazer 302
                  Hypertherm 380 Plasma
                  Air Liquide M200 MIG

                  Comment


                  • #10
                    You would think that the manufacturer would have an engineering dept. contact that would like to speak to you about this. I think you should go right to the source on this one if you feel like it is a base material issue. JEFF
                    200DX 350P 625 Plasma & other stuff I forgot

                    Comment


                    • #11
                      I have the same issue with the mild steel 1x2 tube I've been getting from the scrapyard. Seems if you get to big of a puddle all of a sudden little sparks fly from the weld and the puddle sort of sizzles and boils. I'll cut a couple of short pieces so I can clean the inside of the tube and weld them together. I suspect once the puddle gets full or close to full penetration oil or rust preventer is soaked up into the weld.
                      Dennis


                      Thermal Arc 185-TSW
                      Millermatic Challenger 172
                      VictorO/A
                      Atlas Craftsman 12 by 24 Lathe
                      Esab PCM-875
                      Wholesale Tool Mill-Drill

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