Kamus of Kadizhar wrote in message news:pan.2004.05.28.12.55.42.121711@NsOeSiPnAeMr. com...
Maybe this isn't the right group, but I can't find the right one, so
appologies in advance if this is OT.

I'm trying to build some Leyden jars
http://chem.ch.huji.ac.il/~eugeniik/instruments/archaic/leyden_jars.htm .

A Leyden Jar is basically an insulating container (glass, plastic) with a
thin coating of a metal conductor on the inside and the outside.

Normally, you apply a metal foil both inside and outside the container.

But... I want to build these inside wine bottles, so I can't reach in and
apply a coating by hand.

I've thought about metallic paint - thinning it and swishing it around.
Something like this: http://www.lessemf.com/292.html . I've though
about electroplating, but that doesn't seem practical.

To prevent sparking, the coating needs to stop about 1/3 of the way from
the top of the jar.

Any suggestions for coating the inside of a container with a conductive
film, without actually reaching in? Oh, and this is being done on a
shoe-string budget, so expensive solutions are out....

TIA,

--Kamus

Foil outside, shot inside. Lead shot runs about $12-15/25 lb bag, you
should have enough to do a number of bottles, depending on size, out
of one bag. BBs also spring to mind, not as heavy, copperplated,
probably not as cheap. A book on electrostatic generators I've got
has construction details for Leyden jars made with shot filler, they
used beaded chain for making contact with the top ball. You could
also use salt water for a filler but you'd want to make sure that all
your pieces were non-corrosive and cork the thing up well,
electrostatics and humidity don't get along. IIRC, one of my really
old "electrician's" books has details on making Leyden jars that way,
too, I think they floated mineral oil on top of the salt water. I
think they used dry cell carbon for making contact inside. #6 dry
cells are antiques these days, I don't know what you'd use to
substitute.

Stan