Announcement

Collapse
No announcement yet.

Drop the answer on tungsten

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • H80N
    replied
    Originally posted by ryanjones2150 View Post
    I really like using 2% lanthanated. Just one piece of tungsten and done.
    +1............

    Leave a comment:


  • ryanjones2150
    replied
    Drop the answer on tungsten

    I completely agree with your theory, Willie.

    I don't over-think things (LIAR!! Says my wife...), which is another reason why I really like using 2% lanthanated. Just one piece of tungsten and done.

    Leave a comment:


  • WillieB
    replied
    I have some unproven theories based on proven physics in other applications. TIG welding is all about the flow of electrons. Electrons flow from the power source through the cable, torch, tungsten, arc, workpiece, "ground" cable, and back to the power source. In aluminum and a couple other metals AC is used, meaning the direction of flow is reversed again and again. This is a series circuit. In a series circuit, resistance, or impedance divide voltage. The portions of the circuit offering most opposition to the flow gets the most voltage. If we measure voltage in the circuit mid arc, we find the point with most voltage generates most heat. Ideally, we wish all the heat could be concentrated in the weld joint. We want to melt filler, and enough workpiece metal to liquefy and mix them. Heat elsewhere is usually undesireable. No, I'm not referring to preheat, that's another matter.


    A close arc, only the width of the weld is usually a goal. DC this is less difficult. AC the reversing of flow means part of the arc originates from a larger area than the tungsten.


    We want to reduce impedance in the tungsten. The excessive heat in a long wide arc is usually not beneficial.

    Within the generic term impedance is electricity's reluctance to change directions. Looking at a ground tungsten under a microscope we would see giant grooves, and jagged ridges. At the same magnification we would be unable to see electrons. They are too small. To flow from one ridge to another they must either leap from one ridge to another, or go the long way into the valley. This offers lots of impedance. The long taper ground in a needle shaped tungsten places impedance away from the work, overheats the tungsten, causing melting, or splitting, and wasting heat needed to melt metal.

    A blunt taper will not impede the flow of electrons as much. The heat now primarily in the arc where most of the voltage is will now melt the point only to liquid flowing those "mountain peaks" into the "valleys". This further reduces impedance.

    Leaving the cylinder shape in the tungsten longer increases the distance from the cup to the point where the electrons jump out into plasma, reducing arc wander.

    It's theory I dreamed up, I could be wrong. It seems to work for me. much less true with DC.

    Willie

    Leave a comment:


  • WillieB
    replied
    DC as in steel or stainless is usually Electrode negative, Electrons and heat flow away from the tungsten to the work. In my opinion finding a tungsten that will hold up in this condition isn't hard. In old school sine wave machines, known as transformer welders on AC to weld aluminum are 50% EP. This might seem like a lot of EP, but the sine wave falls to zero twice a cycle. Re ionizing on the eP side of the cycle is hampered by oxides on the workpiece surface. The result is the electron flow, and heat to the tungsten is weakened. These machines could use pure tungsten. Inverter machines switch to EP so suddenly that ionization is not lost, the return arc is strong. It brings considerable heat. The tungsten must be ground blunt to maintain shape. Alloys must be heat resistant.

    Leave a comment:


  • Synchroman
    replied
    2% Lanthanated is an excellent all-around tungsten for aluminum, steel and stainless steel. That said, I still use 2% thoriated for steel mainly because I have a lifetime supply of it.

    When used on aluminum with AC on my Syncrowave 200, Thoriated will make a nice ball, but after a while, sometimes it will appear to split on the end and make extra smaller balls on the side. So, for aluminum anyway, I use Lanthanated.

    I also have a double lifetime supply of pure Tungsten so, from time to time, I like to use that for practice on aluminum. If you can weld aluminum with a large ball as is generally formed on AC current, you won't have any trouble with Lanthanated or Thoriated.

    I know welders who still use only 2% Thoriated for everything. It could be that some machines won't cause the tip to split on AC. It doesn't happen to me at lower heats, however.

    So, I would have to agree that 2% Lanthanated is an excellent choice, although I haven't tried Ceriated or the Triple-blended style as sold by Arc-Zone - mainly due to the abundance of other types that I have. I have a couple of boxes of 3/32" Lanthanated since I generally use 3/32 for most of my work. If I buy anymore, it will be Lanthanated.

    Leave a comment:


  • H80N
    replied
    Thoriated (RED) Tungsten

    Your next question is probably about the use of Thoriated electrodes..

    many of us still use it periodically even though 2% Lanthanated performs better.... my excuse is that I still have a drawer full of it... and it performs OK..

    Then there is all the noise about radioactivity of Thoriated...
    here is a pamphlet worth reading..

    http://www.diamondground.com/thoriat...-discontinued/

    How's That..??...

    Leave a comment:


  • ryanjones2150
    replied
    Drop the answer on tungsten

    I sharpen my tungsten for aluminum. I'll dress the point for tacking then let it ball however it wants to ball up.

    Leave a comment:


  • Midnightillusions
    replied
    Your guys are great help.
    Thanks very much.
    I'll be reading up on this. Cheers

    Leave a comment:


  • Ironken
    replied
    Here's some very basic dope from my Syncro 210 quick reference card. Click the attachment.....its just a screen shot.
    Attached Files
    Last edited by Ironken; 08-27-2015, 10:25 AM.

    Leave a comment:


  • H80N
    replied
    Originally posted by Midnightillusions View Post
    Thanks for the reply guys.
    When your saying one tungsten for everything, now I'm just assuming is that the purple tip one?

    Another thing....
    I have herd a while ago of people sharpening a tungsten to weld aluminum??
    Someone explain this lol
    BLUE not Purple 2% Lanthanated

    on grinding... Tungsten prep... typically tapered and blunted

    here is a guidebook you might download..

    http://www.diamondground.com/TungstenGuidebook2013.pdf
    Last edited by H80N; 08-30-2015, 05:52 PM.

    Leave a comment:


  • Midnightillusions
    replied
    Thanks for the reply guys.
    When your saying one tungsten for everything, now I'm just assuming is that the purple tip one?

    Another thing....
    I have herd a while ago of people sharpening a tungsten to weld aluminum??
    Someone explain this lol

    Leave a comment:


  • H80N
    replied
    Originally posted by ryanjones2150 View Post
    One step ahead of me brother!
    I'm older.... & Just got lucky... I guess.....

    Leave a comment:


  • ryanjones2150
    replied
    Drop the answer on tungsten

    One step ahead of me brother!

    Leave a comment:


  • ryanjones2150
    replied
    Drop the answer on tungsten

    You're gonna get a lot of opinions on personal preference, which is good to hear many people's preferences.

    I personally use 2% lanthanated for everything on all my machines, inverter and transformer. But that's mostly because I like having one tungsten for everything. I'm still using up the last of my thoriated and I have some pure tungsten that I'll probably never use.

    Check out this video from the welding ninja Jedi on the topic:

    http://welding-tv.com/?s=Tungsten

    Leave a comment:


  • H80N
    replied
    Originally posted by Midnightillusions View Post
    I could google my life away. But there is smart cookies on this board. Someone wanna give a quick breakdown on these different style tungsten. Do some hold heat better then others?
    Are some more toxic then others.
    Inquiring for best tungsten for stainless and aluminum.

    What are your suggestions guys. Thanks.
    2% lanthanated Tungsten


    http://www.weldingtipsandtricks.com/...lectrodes.html

    https://www.youtube.com/watch?v=DzEuV83UGMY

    https://www.youtube.com/watch?v=bpanERwagaU

    Last edited by H80N; 08-27-2015, 07:30 AM.

    Leave a comment:

Working...
X