As a footnote to the previous discussion, it seems to me that the best type
of plating for camera parts is electroless nickel. The advantages of this
process are that the plating is extremely uniform on highly convoluted
surfaces.
As some backgroud, electroplating requires an anode and cathode in a chemical
bath. Electricity is applied to the anode and cathode, and the anode, which
is a pure metal of the kind that you're plating, like nickel for example, is
erroded and deposited on the cathode, which is the part to be plated. I think
I've got that right. Anyway, the problem comes from the "Faraday Cage
Effect", where electric charges collect on pointed parts of the cathode,
causing more metal to be deposited there than in deeper crevices. This
applies to powder coating also, since a high voltage electrostatic force is
used to drive the powder onto the object to be coated. So, this could be a
problem for convoluted camera top covers. A further problem in regards to
powder coating is that the part is then baked at I think 400degF for an hour
or so, which could cause warping in small, thin metal parts like camera tops.
Electroless nickel plating uses a chemical process to generate the
electrostatic force that causes the metal to be deposited on the part. The
bath of chemicals are raised to just about boiling, around 212degF, then the
part is suspended by a string in the bath. The rate of plating is about one
thousandths of an inch per hour. A thousandths of an inch is plenty thick
enough for camera parts. The bath will fizz during plating. Also, the part
has to be "cleaner than clean", completely free of any and all residues,
including paint, oil, etc. So, since this process only requires a temp of
about 212degF, it's safe for many parts. Finally, don't do this in your
kitchen, since the fizzing chemicals will get on your walls and cabinets. Ask
me how I know.....<g>
--
Be Seeing You.
Dirk Wright
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