Re: Saltwater Caps

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Original poster: "Dr. Duncan Cadd by way of Terry Fritz <twftesla-at-uswest-dot-net>" <dunckx-at-freeuk-dot-com>

Hi Antonio!

Thanks for some useful insights.

>I have not tried to make an electrostatic machine using glass plates,
>but I made some capacitors (Leyden jars) with glass. Comparing with
>most plastics, they leak a lot, apparently through the surface.
>Varnishing the surfaces, or simply applying some wax, makes a good
>difference.
>Classical machines with glass plates, capacitors, and other glass
>insulators were always varnished with shellac varnish or covered with
>sealing wax.

This is back to polar surfaces adsorbing water molecules as per Gary's
work with wire insulation.  Makes a lot of sense.

>I don't know enough about glasses to translate the old recipes to
>modern glasses, but I imagine that too "alcaline" glasses
>are bad, because they attract water.

Yes, I think a lot depends on that all-too-critical surface layer.

>Borosilicate glass, as "Pyrex",
>is better (I have made some good Leyden jars with Pyrex glass,
waxed).
>What kind of glass is used in those big insulators seen in high-
>voltage power transmission lines?


No idea.  Some are clear glass and others brown and opaque.  I know
there are some professional HV distribution engineers on this list,
maybe they know?

Dunckx