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Re: Rubber toroids [plating]


From: 	Harri Suomalainen[SMTP:haba-at-cc.hut.fi]
Sent: 	Wednesday, October 29, 1997 3:02 AM
To: 	Tesla List
Subject: 	Re: Rubber toroids [plating]

On Tue, 28 Oct 1997, Tesla List wrote:
> > One possibility is rotating the object in the solution. As I began to
> trying to plate a large sphere or toroid while floating it in a plating 
> tank and then rotating the whole deal is going to get very problematic to 
> say the least!

I was actually thinking more about toroids. Making toroids would still
seem very simple by putting eg. copper foil to fill the center. Then
coat with some conductor (like graphite). Then you would only have to
get the tubular part to the solution. That would mean a lot smaller
container would do. Imagine a setup like this:

               O
axis  _ _ _ _ _|
        _____  |  _____liquid level, top of the container
        |      O      | <- container wall
        ---------------bottom

That seems still a nicer approach *at home* than making a huge container
and sinking a 6' toroid in it :) That would require *huge* electrodes too!
Of course, now that the brush idea is out that idea is probably dead born.

> Doing it with copper chloride is alot faster than with copper sulphate.

That probably has a lot to do with the movement of tie ions (if anyone
is interested ;) Movement speeds for ions in electolysis solution will
indeed limit the speed of process (by limiting the current).

> first it looks like nothing is building up, then after a few times around 
> the whole surface starts to show progress and it is a better surface for 
> all your efforts. The rule in plating is the slower it goes on the stronger 
> it builds. When the plating goes fast the copper grains are bigger and 

Has your method resulted in toroids good enough? Is the coat strong
enough? I'd hate to do one just to see copper flake of fairly soon..

> courser thus more likely to crack and peal BUT when the plating goes slower 
> the copper grains are smaller and pack closser together thus making a less
> porous and stronger surface.

As stated before, current can also be used to controll the process speed.
However, as enough voltage is required for the process to happen at all
the controll range is limited to certain voltage range.

> Starting off with just a rubbed on graphite coating is going to lead to a
> LOT of pealing and cracking off of the plating! It  doesn't really bond

Agreed.

> well enough to do lasting plating on. Now if you use Aguadad, or a graphite
> with shellac mixture that will both bond to the painted surface and yet
> still have reasonable conductivity, then the plating with a foam brush will
> have little or no effect of the bond between the graphite and the surface.

Good. That's exactly what I was a bit worried about.
--
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