RE: Water absorbtion of Gray PVC

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

Original poster: "Chris Arnold" <chris_arnold-at-msn-dot-com> 

Gary,

I have seen a secondary coil burn up from the inside out, but it was on a 
~1000 W SSTC and the wire was passed via a sharp bend to the inside of the 
tube.  It also did not have any baffles inside to prevent such failures.

Chris Arnold


>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: RE: Water absorbtion of Gray PVC
>Date: Mon, 08 Dec 2003 08:10:37 -0700
>
>Original poster: "Lau, Gary" <gary.lau-at-hp-dot-com>
>
>I dare say that I've seen far more successful secondaries built without
>sanding and Glyptal than I have seen engines without changing oil.
>
>Further, the secondary failures that I have seen have all been due to
>racing arcs or pri-sec arcing, affecting only the exterior surface of
>the coil, generally polyurethane.  I've never heard of a failure
>originating on the form _beneath_ the winding.
>
>Gary Lau
>MA, USA
>
>
> >Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com>
> >
> >All PVC is hygroscopic especially when used at high frequencies.  It's
>best
> >to sand interior and exterior, then paint with 3 separate of Glyptal or
> >other HV insulation.  Interior sanding is rapidly accomplished by using
>a
> >sanding "flapper" on a dowel (or other extender) on an electric drill.
> >
> >Some experimenters would say this is totally not necessary.  I recall a
> >friend in high school who put over 90,000 miles on his Mustang without
>ever
> >changing the oil . . . . . . . . . . . . . . . .but, I can't recommend
>this
> >procedure.
> >
> >Dr. Resonance
>