RE: Any problems with black UHMW

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

Original poster: "Steve Conner" <steve.conner-at-optosci-dot-com> 

 >You might ask them for the dielectric breakdown specs on that plastic?

I used black HDPE to build some parts of my OLTC, and I did look into the
dielectric properties of the stuff.

It seems that the black _is_ actually carbon, but the plastic is still a
pretty good insulator, as it apparently takes a lot more carbon to make it
conduct than it does to dye it black. The carbon gets trapped in little
globules surrounded by plastic.

But it's still not quite as good as electrical grade white HDPE, in that the
resistivity is slightly lower. (Bear in mind that resistivity isn't
necessarily related to breakdown strength, I couldn't get a figure for the
latter)

Hence I didn't use it for anything that would see serious electrical stress,
like the secondary former itself. Rather I used it for stuff like end caps
and strike rail insulators.

Steve C.