Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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Silver nitrate solution for silver plating with non-toxic bath
2005
Q. Dear Sir,
I am sorry that I need to ask you these questions. But I do not know to who I need to turn to. In Belgium, electroplating is here an almost dead profession and those who are still doing it are not so eager to share information.
I am only interested in silver plating (as a hobby!). In a very old book I found a procedure to silver plate using a non-toxic bath consisting out of:
30 parts of silver nitrate
70 parts of thio urea (I think it plays the role of cyanide as leveler)
1000 parts of water
using a tension of 1.5 V and 0.2 A per square decimeter.
They swear it gives good results...
The book was made for households in the fifties (not industry) so I am pretty confident nothing really dangerous is standing in. But after scouting the internet I don't know anymore. So I would like to ask you one very specific question before I start (if I start at all):
1) If I make this solution (20 l) and could I leave it safely for several months in my garage (in summertime it can become quite hot there). Can toxic side products like nitrogen dioxide still emerge and kill me?
I am not completely ignorant in Chemistry. I have a masters degree in chemistry (specialty organic). But since this is inorganic ...
Would you please be so kind to advise me?
Pattyn S.
PS
I don't think this book is available in America and after scouting around the internet I think it is not so easy to find information for plating Indium, Cadmium, Lead, Aluminium.
But probably you will already have them.
Pattyn Siegfried- Belgium
2005
A. Hi Pattyn. I doubt that there would be any substantial emission of toxic gases from having such a solution in storage, and NOx is unpleasant, not stealthy. But such processes should always be ventilated when in use and may emit NOx vapors. My biggest concern when anyone proposes silver chemistry is the possibility of accidentally producing explosive silver fulminates. As an experienced chemist you should be able to google that term, appreciate the chemistry, and make sure you avoid the possibility.
I've said before that I don't think electroplating plating is a very good hobby, but if you just want a very thin coat of silver on copper, there are "immersion silvering" solutions that just wipe on. See our on-line article "Silver Plating at Home". Best of luck.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
A. Thiourea is a known carcinogen.
Dave Wichern
Consultant - The Bronx, New York
2005
A. Silver plating solutions are a regulated material, even without cyanide.
James Watts- Navarre, Florida
2005
2005
A. Ref handbook
AgCl 20-40 g/l
K4Fe(CN).3H20 120-200 g/l
K2CO3 15-20g/l
brightener Na2ADTA
T-18-55 C
ANODE SILVER
GOOD LUCK, GOD BLESS THE EARTH.
Khair Shishani
aircraft maintenance - Al Ain, UAE
Cyanide-free silver plating process for Martensitic Steel
RFQ: Are there any companies in the states who manufacture a silver chloride / potassium chloride, non-cyanide silver plating solution solution that DOES NOT utilize a copper pyrophosphate or Electroless nickel strike for adhesion? I am looking to plate aviation components (12% Chromium Steel) with silver to 7.62-12.7 microns.
Nigel D Gill, B.Sc. MIMF AIEMATechnologist - Blantyre, Glasgow, Scotland
2003
May 2014
A. Hi Nigel. Sorry, I can't answer your question directly. But two supporting advertisers of finishing.com who offer non-cyanide silver plating solutions are EPI / Electrochemical Products Inc. [a finishing.com supporting advertiser] and Zinex, and you could inquire of them about plating directly on martensitic stainless steel. Good luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
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