Re: Toroid Plateing?

From: 	Alfred A. Skrocki[SMTP:alfred.skrocki-at-cybernetworking-dot-com]
Sent: 	Wednesday, December 03, 1997 2:18 PM
To: 	Tesla List
Subject: 	Re: Toroid Plateing?

On Monday, December 01, 1997 12:15 AM Scott Stephens
[SMTP:stephens-at-enteract-dot-com] wrote;

> >Just finishing making a small toroid(6"x2") from florist foam covered with
> >spackling compound.
> >
> >Is there a way I can plate this thing at home, or maybe paint it with some
> >sort of conductive paint?
> get it sticky with glue, dust with graphite or finely powdered carbon,

Graphite is ok but the carbon is actually a relatively poor conductor, it 
would be much better to use fine aluminum, zinc, copper or brass powder.

> submerge, dip, rotate, et. in a solution of copper sulfate, sulfuric
> (battery) acid and distilled water. Add a little gelatin if it 'tree's.

You end up needing outrageous sizes in plating tanks if your going to 
submerge the toroid, it's A LOT EASIER to brush the plating on by;
connecting one side of your power supply to the conductively coated toroid 
which is your cathode and running the other side of the power supply 
through a wire to a foam brush (this then becomes the anode) and 
periodically dipping the brush in the plating solution then using the brush 
in painting like strokes as the copper slowly builds on the toroidal form.

> Use a copper pipe/wire anode, and the cathode is the object to be plated.
> 5 to 12 VDC, can be pulsating. I IIRC, up to 10A/squr inch (cooled), plates
> around .001"/20 minutes. Make sure object is clean. 

You will get irrational copper build up unless the anode is either flat or 
curved to match the general outward shape of the cathode, so if your going 
to use a plating tank cut the lengths of pipe open and flatten somewhat. 
As for clean - yes, VERY clean! It is common in the plating industry to 
electrolyticaly clean the parts before the plating is begun (this kind of 
etches the surface presenting extremely clean surfaces for the metal ions 
to attach to), but that is next to impossible if your starting with an 
adhesive/powdered metal conductive base. You can clean the surface of all 
grease and fats by gently washing it with a warm washing soda solution 
(Sodium Carbonate),it's not as harsh as lye (Sodium Hydroxide) so 
it's better considering the nature of your starting surface DON'T USE
ACETONE OR ANY SOLVENTS they will remove your conductive surface as well as 
any grease and oils you may have! 

> Do a web surch on electro-forming, electro-typing, electro-plating, et.
> Metalworking FAQ has info on it, too.

I worked in the industry (in a pilot lab) for a couple of years and I
noticed a general tendency to call the whole field "Electrochemical 
Machining", so you may want to search under that as well.


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