Subject: Plating kits from J.C. Whitney

From: [email-masked] (Joe Konecny)
Date: Mon, 11 Oct 1993 01:09:10 GMT

Has anyone ever tried these kits?  They have a metallic brush and you dip it in some solution then brush the part.  The part is grounded and the brush is  
positive.  (or the reverse)  I think you can use a car battery for power.  
I don't need to do this but I'm wondering if it works at all.

-- 
*************************************************************
* Joe Konecny - Computer Science Student, BGSU              *
* Bowling Green State University, Bowling Green Ohio        *
* Internet - [email-masked]                          *

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From: [email-masked] (James W. Swonger)
Date: Tue, 12 Oct 1993 13:17:37 GMT

I have made my own spot plating setups, for zinc. You need an anode, an
appropriate electrolyte, a wick medium (I used rolled-up felt for the pen
and an ordinary sponge for the larger ones), and the handle/package. My
first one I made by gutting a fat magic marker, rolling up a layer of
felt with a layer of sheet zinc like a jelly roll. This went in the barrel,
and a smaller roll of felt went through the tip and butted to the anode roll.
A wire soldered to the far end and passed through the cap feeds the plating
current.

 As mentioned, the plating action is pretty slow. You will need to periodic-
ally re-wet the wick, and use a constant motion over the work spot to get a
decent coverage. The plating current will be primarily limited by the 
product of the resistivity of the electrolyte, the length of the path from
the anode to the workpiece, and the cross-sectional area. For these 
factors the pen design is pretty bad. If you forget ergonomic and 
marketing considerations, the best form is a small disc of anode material,
a thin, uniform/fine weave separator wick and a backside electrical 
connection/handle. Like so:

           \\\
            \\\
             \\\
              \\\   Metal rod soldered to
     Handle    \\\   anode backside, conn. to
                \\\   plating current source
                 \\\
               #######  <- Anode
               -------  <- Separator/Wick
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
       Workpiece, conn. to negative supply

 Minimize the thickness of the separator but not to the point that it
retains no electrolyte. A small amount of adhesive can be used to attach
the separator material wrapped around to the anode backside, leaving the 
face clear.

 For pieces with some surface relief, you may want to experiment with
other ion delivery methods. An idea I haven't had time to mess with is
the use of a fluid stream passed through an anode orifice and directed
at the cathode workpiece, with the charge transport assisted by the
fluid flow and the electrolyte recovered and circulated by a small
pump. I feel this might greatly improve the plating rate compared to
field-only transport. Such a system could be set up to shoot a plating
"jet" at the workpiece, and left to work overnight. The pen type setups
need to be moved around or the plating will be very spotty.
-- 
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From: [email-masked] (Len Moskowitz)
Date: 12 Oct 1993 10:11:01 -0400

Joe Konecny <[email-masked]> wrote:

>    Has anyone ever tried these kits?  They have a metallic brush and
> you dip it in some solution then brush the part.  The part is grounded
> and the brush is positive.  (or the reverse)  I think you can use a 
> car battery for power.  

Edmund Scientific has a brush plating kit with a few different types of
plating solutions.  The brush uses two AA cells and works well.

-- 
Len Moskowitz
[email-masked]