Re: Water As Dielectric

To: "'Tesla List'" <tesla-at-poodle.pupman-dot-com>
Subject: Re: Water As Dielectric
From: Tesla List <tesla-at-stic-dot-net>
Date: Sun, 9 Nov 1997 13:21:12 -0600
Approved: tesla-at-stic-dot-net

From: 	Alfred C. Erpel[SMTP:aerpel-at-op-dot-net]
Sent: 	Sunday, November 09, 1997 9:41 AM
To: 	'Tesla List'; Tesla List
Subject: 	Re: Water As Dielectric

AE>>>>>>>>>     Is distilled water considered to be a viable dielectric
material
for a plate capacitor? High voltage vs. low voltage? DC vs. RF?  Since it's
k=80+ it would seem to be a good choice.  As a toolmaker, I would have no
problem making a sealed, watertight plexiglas cube, void of air, with evenly
spaced copper plates inside, and I would like to do this if someone doesn't
tell me it is a dumb idea.     What is water's dielectic strength? I did a
search on the internet for this value and the only thing I kept finding was
it's dielectric constant.<<<<<<<<<<<<<<<<<


SA>>>>>>>>>Hello, I've no personal experience of using distilled water as a
dielectric, and I'd be surprised if anyone else has ... if you can keep
the water pure it would be ok, but even tiny ammounts of
contamination (any alkali, acid, salt etc.) would make the water a
conductor. I think that your capacitor plates (Aluminium, Copper,
whatever) would contaminate the water enough to destroy it's
insulation properties. Personally I wouldn't bother trying - use oil.
bye ... Sulaiman<<<<<<<<<<<<<

    Thx.  My chemistry is shaky, but, I was under the impression that
distilled water (containing no ions) would be unreactive with metal (true
metals not sodium et.al.).  But assuming this is wrong, and there is some
sort of slow ion formation which would cause conduction, the following comes
to mind:
    The copper (or other metal) plate could be chrome or nickel plated (or
something else) to reduce/eliminate ion formation. And possibly ion
formation could be held to such a slow level that they would be "burned off"
as they were formed by the charge in the capacitor at such at a rate that
this would be inconsequential to certain types of uses.
    Possibly there would be some reagent that could be added to the
distilled water to neutralize the (potential) effects mentioned above.
    I persist on this topic because the combined benefits of distilled
water's dielectric constant of 80, it's safety and availability are too
attractive to just give up on.