Ruthenium Plating Process
A discussion started in 1996 & continuing through 2017(1996)
Q. I've been doing some electroforming of gold onto copper mandrels and etching out the gold with nitric acid. Now the customer wants to have a "medium Z" material (Ruthenium to Antimony) electroformed. In one of the ancient "Ask plater B" queries I had read a response to a similar question which suggested Ruthenium as being resistant to attack from nitric acid. Is this true? Can I plate Ru directly onto copper? (The customer doesn't want stress cracks so I've shied away from Rhodium). I need to plate ~25 microns (1 mil) onto the substrate. Does Ru sound possible?Fred E [last name deleted for privacy by Editor]
Need lower temperature Ruthenium Plating(2003)
Q. Usually Ruthenium is electroplated at temperature of 60-70 °C. In my application, I need to plate Ruthenium at a temperature of 50 °C or lower. Is there such chemical and process available?
- Milpitas, California, USA
Want Jet Black Color with Ruthenium PlatingJune 21, 2008
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 have 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 don't 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,
- Chennai, TN, India
June 25, 2008
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?
process engineer - Malone, New York
June 29, 2008
A. Hi, Sudhir Ostwal,
Ruthenium plating, and bath not pen plating, as Mark said rightly is the answer.
There are supply houses making and marketing Ruthenium process. But I want to tell you that this will not be jet black in colour but an attractive dark grey.
Kindly look around in your city itself as I understand there are suppliers of this process.
plating process supplier
March 10, 2010 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread
Q. Hello, I am a goldsmith. I'd like to have a new design on our gold and silver collection of chains and pendants. I want to use Ruthenium bath to give a black color to our gold and silver collection to get a fixed and heat resistant color (I have to solder next components on it after coloration). I want to use a Nickel Strike bath. I heard about Wood's Nickel Strike bath and Sulfamate Nickel Strike solution. Please, can you give me more information how to make it. What solution is better for me. Or if you have other idea how to do it. Thank you very much. J.T.Jana Tietz
goldsmith - Czech
Earliest known use of ruthenium plating on 18k white gold?(2005)
Q. Hi - I'm a hobbyist jeweller and collector and I'm trying to date an 18 carat white gold pendant found recently at an antique fair.
It has clear UK hallmarks for 18k gold and the London assay office, but unfortunately the shape of the shield round the date letter is obscured, putting the piece somewhere between 1840 and 1960!
The pendant is in a late 19th century / early 20th century style - white gold in a loose fleur de lys shape, pave set with diamonds with pendant aquamarine & peridot briolette drops on white gold chain. However, the gold behind the pave set diamonds is blackened with what I think is ruthenium electroplating, so I assume it must be a much later piece than c. 1900.
Is there anyone out there who knows when ruthenium plating was first used on 18k gold or is aware of any earlier techniques that might have been used to blacken white gold?
collector - London, England
Need Ruthenium plating on hard nickel partsMay 26, 2009
RFQ: My company has a technical application requiring Ruthenium plating on thin hard nickel panels.
If you can do it consistently and reliably this would be an on-going requirement for our business.
An NDA will be required.
Electronics - Minneapolis, MN, USA
June 12, 2012
Q. Hi everyone. I have a question about ruthenium plating onto jewellery!
The obtained layers have a very dark colour. What's the problem?
10 v, 1 min, 65 degrees.
A. Hi, You can use a complex (alloy) solution of ruthenium and rhodium.Gurudatta Thakur
- Mumbai, India
Ruthenium plating onto titanium(2006)
Q. Is a gold strike necessary when plating ruthenium onto titanium or can the Ru be plated directly to the Ti.
RFQ: I need to plate some titanium round bar .250 - .500 " dia. with ruthenium oxide. I could use some tech support with this to see if it is practical to do it myself. I would also consider jobbing it out if someone is already doing this.Rusty Shuping
Safe Drinking Water Tech for third world poor - Rockwell, North Carolina, USA
A. Hi Rusty. Rather than definitively answering that, because I can't, I will at least suggest that the hard part is not the electrodeposition of ruthenium, but getting anything to properly plate onto and adhere to titanium. If you are able to get the gold to adhere, count your blessings rather than trying to skip the gold :-)
Please see letter 40558, "Poor adhesion of plating onto titanium", where Hamilton Solidum relates his successful procedure for plating gold onto titanium, or search the site for "plating on titanium". Good luck.
Ted Mooney, P.E.
Pine Beach, New Jersey
How to get harder Ruthenium deposit?November 16, 2013
Q. How to achieve a harder deposit of 0.1 µm of black ruthenium?
Because this deposit is not OK at the wear test (Turbula 30 minutes).
Thank you for your reply.
November 22, 2013
A. Hi Gregorio. Sorry, I'm not familiar with the Turbula wear test. But 0.1µm seems awfully thin to me, no matter how hard the surface :-)
Ted Mooney, P.E.
Pine Beach, New Jersey
Looking to create a durable black on nickel based white goldsMarch 30, 2014 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread
Q. I am looking to create a durable black oxidation on all white golds. Also, palladium and platinum would be a bonus. I have tried pen-plated black rhodium, finding it is not all that black. But it also seems to wear off quickly as well. I have tried tellurium solutions as well and with the same results. Most of these will last only a few days to a few weeks. Has anyone had success with a blackening agent on gold that is very dark, and long lasting? Thank youPeter Jon
goldsmith - Bend Oregon
April 2, 2014
A. We had a customer come to us with a similar problem -- trying to get black on white gold. We didn't see how it could be done with plating, so we applied a black coating by PVD. Worked fine, customer is happy and likely to go into production.
- Vista, California
November 13, 2015
Q. Dear All,
We have a 30 liter tank made of PP sheets; we use it for dark ruthenium electroplating. But our ruthenium electrolyte makes everything including our pp sheets black. How can we fix this problem? I hear there is a stabilizer salt but I don't know it. Hope to hear from you soon.
- Isfahan, Iran
January 6, 2017
Q. I'm looking to purchase a couple items made of
Rhuthenium ^ Ruthenium. Should I be concerned of the toxicity of the element?
- El Campo, Texas, USA
The editor's fave "coffee table book" for years now...
A. Hi Allen. There is no material anywhere which nobody considers harmful, toxic, or allergenic :-)
But ruthenium (we corrected your spelling for better Googling) is a fairly widely used precious metal plating considered by most to not be toxic in any way.
Ted Mooney, P.E. RET
Pine Beach, New Jersey
Striving to live "Aloha"
Black Rhodium vs Black Ruthenium wear resistanceOctober 12, 2017
My fiancé bought me a black ruthenium plated ring, and the plating started to wear off in less than a day. After a week it was almost entirely gone. The shop said they had sold lots of them and it had never happened before, so it must be my skin. Do you think there is any validity to the argument that my skin can break down a metal as hard at this? They are getting it re-plated; I asked if I could have a thicker plate, or if they could try black Rhodium but they say there is only one thickness option with Ruthenium and that it's better than Rhodium.
I am also a student jeweler so I want to know for the future, what will last longer, black ruthenium or black rhodium? I see lots of posts about the colour, but none about durability.
- London, UK
January 18, 2018
A. Hi Laura,
Rhodium and ruthenium hardness are similar at ~800-1000 HV with excellent wear and corrosion resistance but rhodium price is almost 9 times of ruthenium.
The problem happened on you could due to too thin ruthenium deposit thickness, low ruthenium deposit purity, poor adhesion between ruthenium and underlying metal, too frequent wearing, etc.
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