Re: thoriated electrodes

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

Original poster: "Finn Hammer by way of Terry Fritz <twftesla-at-qwest-dot-net>" <f-h-at-c.dk>

Greg!

I think you can use any sort of tungsten with good results, even
tungsten carbide has been reported to work well, and even show superiour
wear caracteristics.
But you are using 4mm rods at 11 Kw power, right?.
That seems to me to be the real problem. 
Beef the electrodes up to 8-10mm, and you will see, that they last much
longer, to the point where the wear is of no consequence.
The debate about which sort of tungsten metal alloy to use is an old
one, and since Bill Wysock and Ed Wingate both swear by them,
(thoriated) it is pretty hard to argue against it. Those 2 guys have
forgotten more than we will ever know!.
But for the average, intermediate coiler, I don`t think it matters much
which variety you use, as long as it is large enough in relation to the
power level you are applying to it.

Cheers, Finn Hammer

http://home5.inet.tele.dk/f-hammer/tesla/tesla.htm


Tesla list wrote:
> 
> Original poster: "Mr Gregory Peters by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <s371034-at-student.uq.edu.au>
> 
> Sorry guys,
> 
> After reading my post again, I realised that it may not have been
> obvious what I was actually asking, so here goes:
> 
> I have noticed that most coilers use thoriated tungsten electrodes. I
> would have thought that this actually would be bad for TC use, as you
> want to keep the quench time down, and I would imagine that the extra
> arc stability provided by the thorium would be detrimental to this
> cause. Or is it more important to have a stable, reliably firing spark
> gap? I don't know.
> 
> So I was basically asking if anyone has noticed any real difference in
> performance with thoriated vs non-thoriated electrodes. I would imagine
> that for our purposes, little, if any, difference would be observed.
> 
> As my coil eats thoriated tungsten for breakfast, I would rather use
> plain tungsten electrodes if possible, negating any radiation hazards.
> However, if arc stability is more important than quench time, I would
> imagine that zirconiated tungsten electrodes would work better than
> thoriated, as these are used for AC tig welding, whereas thoriated
> electrodes are used for DC tig welding.
> 
> Greg Peters
> Department of Earth Sciences,
> University of Queensland, Australia
> Phone: 0402 841 677
> http://www.geocities-dot-com/gregjpeters