Re: tungsten rods

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Peter Lawrence by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Peter.Lawrence-at-Sun-dot-com>

Chris,
      you pose an interesting question that I too have wondered about.
      
My first observation is that you do not want thorium in the air you breath,
so I would stay away from thoriated rods, period. (I've got a TIG welder and
I've used them, but I've switched to lanthanated which is not radioactive)

Second, the lanthanum (or thorium) increases the electron emissivity of the 
tungsten which is why it is used in both TIG welders, and power triode
tube filaments, this results in more current! Sounds good on the surface
as this might mean lower gap losses, but this might also reduce the
"quenching" property of the spark gap which means higher losses.

In summary, we have here a great experiment for someone on the list to do
and report back about. (I've been using tungsten-carbide instead of welding
tungsten because it is so cheap, or I would have done the experiment myself.
So far my local welding supply store only has up to 1/4" tungsten (I'ld like
some 3/8), and no longer sells individual rods, only boxes of 10, expensive!)

anyone else got some real data???

Peter Lawrence.


>
>Original poster: "chris carsten by way of Terry Fritz <twftesla-at-qwest-dot-net>" 
<ctom-at-toast-dot-net>
>
>I have a chance to get my hands on some tungsten welding rod for my tsg. The
>guy says he has pure tungsten and some 2% chloride. Which would be better?
>He also has various diameters but I would figure that the bigger the better
>here right? Thank you in advance,
>Chris
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