coated carbides

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

Original poster: "Metlicka Marc by way of Terry Fritz <twftesla-at-uswest-dot-net>" <mystuffs-at-orwell-dot-net>

all,
to anyone that may be thinking about trying the carbide inserts for
static or rotary electrodes, i have found that nitride coated carbide
inserts exhibit a strange property. i built a small static gap for a
display coil that used four coated inserts in the center of four
uncoated, when i tried first light, the arcing across the coated inserts
actually looked like there was no tank capacitor in the circuit at all
(weak and purple)? i thought something was wrong with the nst, but when
taped to the uncoated inserts only, the arc was blue\white as it should
be. resistance measurements have shown no differences between the two?
i tried looking up some properties of the nitride coating with no
results other then MSDS labeling, i have no explanation so all i can say
is, DON'T USE COATED CARBIDE!
if anyone has any ideas as to why this is, i would be interested.
thank you,
marc m.