Re: secondary wire diameter

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Terry Fritz <vardin@xxxxxxxxxxxxxxxxxxxxxxx>

Hi Dmitry,

There is "no reason" to make PVC black other than to add carbon to it 
to make it UV resistant to increase the life when exposed to the 
outdoor elements.  There are black paints and such, that are really 
deep purple in color, but why would they do that...

You might try rubbing the black on paper,  If it looks like a greasy 
carbon trace.  It is poison to our HV coils!!!  Real non-conductive 
paint hardly makes a mark...

There are black plastics that are fine, but they are shiny black all 
the way through the material.

It is really not worth using black plastics unless you can test them 
to be sure...  Tell the "guy" to get you some plastic that is not 
black, and then the risk is zero ;-))  As Matt says, the guy normally 
deals with water, not 500,000 volts :o)))

Coils have been made with carbon filled materials that do work for a 
short time, but they fail real bad after awhile....  Best just to not 
mess with black plastics at 500kV ;-))

Cheers,

        Terry


At 07:39 PM 8/17/2005, you wrote:
> In a message dated 8/17/05 7:51:54 P.M. Eastern Daylight Time, 
> tesla@xxxxxxxxxx writes:
> i was there today - the guy told me that black colour is just a dye -
> it doesn`t influence the electric strength of the pipe. but better to
> be overcautious :-)
>
>
>
>
> Hi  Dmitry,
>
>    Almost all black dyes and pigments are at least partially carbon 
> based and so will be a weak point for tracking of HV on the 
> surface. Most plastic pipe salesmen don't know diddley about HV RF 
> applications as even big conduit doesn't carry over 500 V @ 50-60 
> Hz unless it's custom made. Until you can afford another secondary 
> on short notice, better to play it safe and stay away from black.
>
> Matt D.