Newsgroups: rec.crafts.metalworking
Subject: Re: Thoriated tungstun
From: John De Armond
Date: Fri, 15 Oct 93 21:22:49 GMT

jjhenry@ux1.cso.uiuc.edu (Jonathan Henry) writes:

>I understand that thoriated tungsten electrodes commonly used in TIG
>welding are radioactive.  I am particularly concerned about the dust
>generated when grinding electrode tips.  I have since swithched to using
>ceriated tungsten electrodes which are non-radioactive (zirconiated
>tungsten is also non-radioactive).  However they are very expensive.  (Note
>that I like the welding behavior of these new electrodes better, though.)

>Does anyone know if there is a substaintial health risk to using thoriated
>tungsten electrodes?

There is NO health risk from thoriated tungsten.  The amount of thorium
is tiny - normally barely detectable with a common survey instrument.
If this quantity of thorium worries you, then for God sake, don't ever
build a wood or charcoal fire.  There is vastly more thorium in the ashes
than in an electrode.  Don't ever cut or break a common brick either.
Lots of uranium and thorium in bricks.  If you'd like proof, consult the 
Health-Physics Journal from the mid 80s for an article on the subject 
by Stu Farber.

John