Re: Tungsten electrode wear

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

Original poster: Peter Lawrence <Peter.Lawrence-at-Sun.COM> 

Steve,
       there is no reason to use thoriated for SG, stick with pure tungsten
welding rods (color coded green on one end). I make TCs as a hobby, and I
have a TIG welder for other hobbies, I've gotten rid of all my thoriated
rods, and only use pure and lanthanated rods, I figure its got to be safer
in the long run to avoid any type of radioactivity. IIRC, the reason for
additives in tungsten welding rods is to get higher currents, not to wear
longer. Pure tungsten lasts so long is TC-SG usage that its not an issue,
and AFAIK it is tungsten's high melting point that makes it last so long
not the additives.

Best way to secure tungsten rods: drill a hole through the length of a bolt
(that will go through the rotor disk). drill and tap through the head of
the bolt for a set-screw to hold the tungsten rod in place (or what I do
to be slick is slit the threaded part of the (brass) bolt with a super thin
X-acto saw so that tightening the nut makes the bolt act like a pin-vise
chuck).

-Pete Lawrence.


 >
 >Original poster: "S & J Young" <youngs-at-konnections-dot-net>
 >
 >Spark gappers,
 >
 >There is a trend for welders to use lathanated tungsten welding electrodes
 >to get away from the slight radioactivity of thoriated rods.  The lathanated
 >rods allegedly wear slower than the pure tungsten rods.  Does anyone have
 >RSG experience with both kinds to know which composition of tungsten erodes
 >less in spark gap duty?
 >
 >Thanks,
 >--Steve Y.
 >
 >P.s. innovative ideas for securing rods that extend from both sides of a RSG
 >disk would be appreciated.
 >
 >