RE: copper plating

["Lau, Gary" <Gary.Lau-at-compaq-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

I don't understand how you can pass the required DC current through this
arrangement if one power supply lead is inside the cup, and the other is
outside.  What is the 35uF cap?  In parallel with the power supply?  It's
also not clear what the goal of this plating is.  There are two problems
with using salt water as the "plates" in conventional bottle caps.  

The first is the weight and mess of the salt water itself.  But to minimize
corona, if you did away with the salt water, you'd have to fill the bottles
with oil instead of salt water and oil, so there's no gain there.

The second problem with salt water, at least for inside the bottles, is the
resistance of the salt-water conductor between the wire terminal and the
"plate" - the inner surface of the bottle.  Even if you have a nice copper
plating on the inside of the bottle, you've done nothing to reduce the
resistance of the connection to the wire unless your plating is sufficiently
thick that you can actually solder the wire to it.  In the case of your
plastic cups instead of glass, this is unlikely.

Regards, Gary Lau
Waltham, MA USA

		-----Original Message-----
		From:	Tesla List [mailto:tesla-at-pupman-dot-com]
		Sent:	Sunday, June 11, 2000 1:06 PM
		To:	tesla-at-pupman-dot-com
		Subject:	copper plating

		Original Poster: "Metlicka Marc" <mystuffs-at-orwell-dot-net> 

		hi all,
		this is to anyone that has contemplated getting a conductive
surface on
		a non conductive surface, i.e.. on glass or
plastic.(especialy towards
		the thread on using al. powder in a glass cap instead of
salt water). i
		have been trying different copper plating processes to try
to get a
		conductive coating on my "party cup caps".
		these cups i am using are styrene, i have been getting
relatively good
		results plating them by using a copper sulfate bath up to
within an inch
		of the top of the cup on the out side, and filling the cup
to the same
		level of the sulfate with salt water.
		i then hooked up a 30vdc power supply, the negative clipped
to a piece
		of copper tubing and immersed in the sulfate bath, then the
positive
		placed into the saltwater inside the cup.
		i now have a 35uf cap placed across the two.
		this is depositing a copper film on the outside of the cup,
but i think
		i need to play with the voltages and capacitance more to get
an even
		film, (a little splotchy at this time. and takes a long
time). i think
		if i can get this process down a little more solidly there
would be no
		reason you couldn't plate both sides of a glass or plastic
jug.
		i would appreciate any comments on this, and copper sulfate
is used to
		kill pond weeds if any one would want to further this
experiment along
		with me..
		thank you         marc