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  • burning tungston

    i just bought a dynasty 200dx to learn to tig on. the first thing i built was a cart. i am using .065 1x2" rectangular tubing. 2% thoriated (i believe 3/32"-the middle size-not small, not big) tungsten with same diameter filler. my flow meter is set to about 20 with straight argon. my questions are:

    how far should i keep the point out of the collar (#7) when welding on flat.

    how often should i have to sharpen the tungsten? it seems like i have to sharpen it about every 3-5 welds approx. 2 inches long. i don't think that i am dipping the tip in the puddle, but i might be, or just too close.

    my beads come out looking like my mig beads both in color and quality, i thought it was supposed to be shiny and clean, anybody know why?

    in advanced, thanks for the feedback.
    -SPiNNeR-

    Hobart 135
    Oxy-Acet w/ Victor torch
    Dynasty 200 DX

  • #2
    The tig book on the Miller site is very helpful.1 amp for every .001" is a good start but I'm not familiar with the Dynesty settings.As for the weld color cleanlyness is everything.I think I remember from one of youre posts that you did OA welding,those filler rods are not the same as tig rods.I think the coating on the rods might be contaminating the weld a little.Try running a beed without filler and see if that gives you the desired look.My beeds with no filler are a lot cleaner than the beeds where I use filler.As far as tungsten stickout,I recall reading it should not extend more than the cup diamiter for general use.Acording to the charts it looks like you should be useing about 65 amps.That amperage should use tungsten size 1/16 witch would use a 3/8 cup,or #5.and 15 cf argon. I am just learning tig myself so take this for what its worth.
    To all who contribute to this board.
    My sincere thanks , Pete.

    Pureox OA
    Westinghouse 300 amp AC stick
    Miller Syncrowave 250
    Hexacon 250 watt solder iron

    Comment


    • #3
      Spinner

      A 3/16" stickout is ok on the tungsten but I don't think that is your problem, it sounds like you are using cold rolled mild steel.
      One way to tell is that you will see little sparks coming off of the base material as your welding and that is contaminating the tungsten, if this is the case lightly grind the surface to remove the mill scale this will take care of the problem.
      You may still experience some gray looking welds but that can be caused by to much heat, remember it will never look like stainless.
      Mark K.
      Welding Technician
      Miller Electric Mfg. Co.

      Comment


      • #4
        that sounds like a good rule of thumb that the tungsten should not stick out further than the width of the cup. that sounds right to me.

        i think that i might be using too thick of tungsten. it sounds like i should be using a #5 cup and appropriate rod, i'll try changing diameter and see what happens. i also think that i have had the image of stainless in my head, don't know why . thanks for the tips.
        -SPiNNeR-

        Hobart 135
        Oxy-Acet w/ Victor torch
        Dynasty 200 DX

        Comment


        • #5
          My sources say tungsten should stick out no more than 3 times the tungsten diameter. If you use a gas lense you can extend it to 6 times the tungsten diameter.
          I always try to keep the stickout as small as possible. About 1/8" for flat. If visibility or reach is a problem then I go further out. In tube clusters and other tight spaces that can protect from drafts, I will go beyond the recommended amount if needed.
          After welding the tungten may discolor a little bit, or the very end may smooth over, but nothing else. If it gets lumps or splits you are getting it too hot, letting it get out of the shielding gas or contaminating it with weld metal.

          If you contaminate a clean tungsten with steel while welding, you can often see a rusty spot along the bead where it happened. You can accidentally dip the tungsten, or you can hit it with the fill rod and get the same effect.

          A gray looking weld is caused by dirty base metal or getting the weld too hot. If looks matter, you should try cleaning some more. The weld can get too hot even if there is not enough penetration. If getting too hot is a problem you need to go faster. To increase penetration you need to go hotter. Surprisingly enough going hotter does not overheat the weld if you go fast enough. Also remember that the addition of fill rod will cool the weld.

          In my opinion, for .065 steel you are right on the border between using 1/16 and 3/32" diameter tungstens. Try it and see which is best for you. Smaller is better if the point lasts.

          Comment


          • #6
            Originally posted by eric75
            In my opinion, for .065 steel you are right on the border between using 1/16 and 3/32" diameter tungstens. Try it and see which is best for you. Smaller is better if the point lasts.
            That seems to be the problem, right on the border.
            "Smaller is Better", I've always loved those words . I'll try to keep that in mind.
            -SPiNNeR-

            Hobart 135
            Oxy-Acet w/ Victor torch
            Dynasty 200 DX

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