Re: copper vs. aluminum

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

Original poster: "Jolyon Vater Cox by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>

Or you could use copper plus copper chloride (CuCl2).

Salt plus aluminium is simply dreadful combination.


Salt water just rots aluminium -white crusty surface deposits appear and
holes soon form in the metal. Look at aluminium objectwhich have been
exposed to a marine environment for some time -they exhibit just this kind
of corrosion and do not last long.

I have had experience in a TC situation when once used salted wallpaper
paste to aluminium stick foil strips to a polystyrene foam toroid.
 I had previously been making gelled-salt water capacitors and had added
salt to the paste to make the "gel" -some of the paste had been left over
and I used it to stick the foil to the toroid. Silly, I know- a few days
later corrosion spots appeared in the foil -which was found to be eaten
through with holes when I had to removed it.

Worse still, anything alkaline like sodium hydroxide (caustic soda;NaOH) or
sodium carbonate (soda; Na2CO3) these will attack aluminium forming
explosive hydrogen (not good with sparks around) and the reaction gets
faster with with hot solutions
-another good reason not to use aluminium electrodes with alkalis in "salt
water" capacitors.

Jolyon

(----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, August 14, 2002 2:02 AM
Subject: Re: copper vs. aluminum


> Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<jimlux-at-earthlink-dot-net>
>
>
> unless you use CuSO4 as the salt...
>
> Tesla list wrote:
> >
> > Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <davep-at-quik-dot-com>
> >
> > > you are better off using Aluminium
> >
> >         Concur.
> >         And Cu is more likely to corrode/electrolyze in
> >         Salt water....
> >
> > > ----- Original Message -----
> > > From: "Tesla list" <tesla-at-pupman-dot-com>
> > > To: <tesla-at-pupman-dot-com>
> > > Sent: Tuesday, August 13, 2002 7:30 PM
> > > Subject: copper vs. aluminum
> >
> > >>Has anyone yet tried using COPPER foil in their saltwater
> > >>caps, instead of aluminum?  Seems that copper would be a
> > >>better choice, due to being a better conductor,
> >
> >         But not hugely so.  Also cheaper, so can use
> >         more Al to get same conductivity.
> >
> > >> and also being able to solder to it...
> >
> >         Good point.  IIR trick aluminum solder can
> >         be found....
> >
> >         best
> >         dwp
> >
> > ...the net of a million lies...
> >         Vernor Vinge
> > There are Many Web Sites which Say Many Things.
> >         -me
>
>
>
>