I have been pen-plating sterling silver with black rhodium for about
2 years now, and here is my experience:
For gold- and rhodium plating I use “Rhodinette, fiber electrode
plating system” a german make pen-plating outfit. I buy the rhodium
bath in 100 milliliter bottles. They are rather expensive, such
bottle costs about $ 100.
After rhodium plating, the jewellry will retain the same surface
structure as the silver had before plating. So, when I need a glossy
black surface, I must glossy-polish the piece before plating.
Room temperature is important. I never heat my liquid Rhodium,
but I try to keep the roomtemperature 23 degrees centigrades or
higher, at least one hour before I start plating. This gives all
liquids the same temperature.
Degreasing is also very important. After ultra-cleaning and
drying, I dip the jewellry into 10% sulphur acid solution for a
minimum of 3 minutes, (herafter no fingerprints on the surface to be
plated! I use latex gloves), then I wash it thoroughly in tepid tap
water, and dry it with clean kitchen roll. After plating, wash and
dry as usual. I do not use this sulphur-solution for pickling! I
prefer to use tapwater rather than destilled water, because the first
is always fresh, while the second will slowly contaminate. The water
quality here gives me no problem.
Cleanliness is alfa and omega when plating!
The “Rhodinette” comes with small glass-containers, colour-coded for
each plating-bath. When washing the containers, I use distilled
water. I only pour as much rhodium bath into the container, as I
estimate to use in one plating session. I never pour the bath back
into the bottle again. If the liquid in use becomes contaminated I
will ruin my stock, if I pour it back. Unfortunately, "Rhodinette"
has it’s own scale of electrical power, which goes from 1 to 10,
instead of using voltage, so I never know how strong current I’m
using. Naturally I go by the instruction booklet but I also do a
little experiment to find the best voltage for my job.
I use my “Rhodinette” both for black rhodium- and gold plating For
each kind of plating, I use seperate felt-tipped pen. These come in
different colours too, and should be kept apart. The rhodium bath
contains acid and the gold bath contains cyanid. As we all know,
these two things will produce a rather nasty effect, if mixed.
I like my Rhodinette, but there are other makes out there, probably
just as good. Further info.: www.wieland-industrie.de -and here the
adress to the US agent:
10, West 47th Street
New York, N.Y. 10036
Phone: 212 944 4944
Fax: 212 921 2412
They can probably supply the baths as well.
Jon H. Holm