49098

Jet Black With Rhodium or Ruthenium  

June 21, 2008

Hello

My Name is Sudhir, I m basically a watchmaker, recently my client in Belgium wanted me to plate his watch movements in black colored, I have been using white rhodium plating on mechanical watch movements, using intermediate coating of Palladium. Ever since my buyer wanted to get black finish, i hv been researching all around internet, i just saw that Umicore came up with "Blacker" Ruthenium product number 479, also i read some articles on net stating that Pen plating Black Rhodium gets a better blacker finish than bath Rhodium, at the same time some articles saying that pen plating dont ever get you even finish

Now i m really not in a position to settle down to any solution, please help me about this problem, I m willing to hire any professional help in this regard,

Thanking you

Sudhir Ostwal
Buyer - Chennai, TN, India

Sudhir,
If you are unsure on what solution to use, have a local precious metal supplier plate some samples for you. Watch movements are very small and it would seem pen plating would be difficult. Bath plating would have lower thickness variations than pen plate because human error is minimized, and bath plating can plate better in recessed areas. It is hard for anyone just to give you a product name to suit your needs. What if the color of the deposit does not match your needs?

Mark Baker
Process Engineer - Syracuse, NY, USA

Hi, Sudhir Ostwal,
Ruthinium plating and not pen plating as Mark said rightly is the answer.
There are supply houses making and marketing Ruthinium process. But I want to tell u that this will not be jet black in colour but an attractive dark grey.
Kindly look aroung in ur city itself as I understand there are suppliers of this processes.

T.K. Mohan     plating process supplier  Mumbai, India