RE: Forget pastic pop bottles use beer bottles.

Steve, my best answers to your queries are:

1) Dont know, maybe on the order of 1 nF, but if you use SW inside AND
OUTSIDE you will get much more.  With plastic, I get 3x the capacitance due
to smoother surface contact on the outside of the dielectric.  

2) Dont know, but have never burst one with NST.

3) I now add MgSO4 to NaCl at the suggestion of Mike Foster.  Jim Lux makes
a good case for CuSO4 when using copper electrodes, but I have not tried it.

4) Yes.  The main part of this will be 'contact' resistance, try using 1/2
in Cu pipe for inner electrodes, a metal pot for the outer electrode.  Get
as much surface area in contact with electrolyte as possible.  Have not
tried 1200 strand copper welding cable yet, but it would have plenty of
area.  Maybe fan the strands a bit.

William E. Payne
275 Oak Hills Dr
Dallas, GA    30132

770-494-1104 (day)


> Original Poster: Steven Ivy <adder_black_the-at-yahoo-dot-com> 
> The questions I have now are. 1) How much capacitance do
> you normally get from your average 12 oz beer bottle. 2) What  is the
> practical TC AC voltage rating for such a capacitor. 3) What is the
> best electrolyte to use of all the commonly available and cheap
> substances CuSO4, NaCl,  or ??.  4) Will the ESR, equivalent series
> resistance, of such a cap really suck?