Silver plating of Musical instruments

A. In order to be able to electroplate a material out of solution, you have to first be able to dissolve it into solution. While iron chloride and copper chloride are soluble salts, silver chloride will precipitate immediately, so you cannot plate from that. Yes, silver chloride is soluble in ammonia, but any time you are fooling with silver & ammonia [on eBay or Amazon] together you are in danger of creating silver fulminates which are incredibly powerful and volatile motion-sensitive explosives -- a speck of which can blow up you and your lab. Personally, I wouldn't even attempt plating silver out of an ammonium chloride solution, but good luck.

A. Thanks Kyle. I think the most practical silver plating baths are cyanide based with organic and inorganic brighteners. You can do a patent search which will reveal expired patents if you do not wish to purchase a commercial formulation from a plating supply house. Cyanide has been the process of choice for 95% of silver plating for over a hundred years, but whether your university will let you use that deadly poison, I don't know. Good luck.

Thank you for the informative response. I will do as you suggest and not try this. This does leave me without a plating solution. Do you have a suggestion of a standard, non-proprietary plating formula? Thank you again. Kyle Olson (As a curiosity, I thought fulminates were stable in solution and gained their notoriously explosive nature once in solid form. I thought that meant dry but if they precipitate out and are thus solid that would meet the criteria for "not in solution." Anyway just my curious naivete and not any suggestion of trying this by any means.)

A. Technic and at least one other company makes a silver plating solution that is cyanide free. You will need a silver strike and I do not know if there are any that are free of cyanide. A silver anode will be necessary for most applications. That will depend on its use. Brush plating is an option, but a workable setup would cost several hundred dollars and its quality is extremely operator sensitive.

A. Other suppliers includeEPI / Electrochemical Products Inc. [a finishing.com supporting advertiser] and Zinex. There are possibly others.

Luck & Regards,

A. Pyrophosphate silver bath:

100 gm potassium pyrophosphate
25 gm ammonium chloride
25 gm silver chloride
stainless steel anode, 30 °C temp. (from one Russian book)

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Ed. note: Goran has asked that this posting be ignored; he has corrected the posting below.

A. I am very sorry but my bath recipe posted above was wrong! Real Russian bath recipe:
15-90 gm silver pyrophosphate,
100-350 gm potassium pyrophosphate,
20-145 ammonium carbonate (not chloride!),
temp. 18 °C,
0,5-12 A/dm2.
From Russian book "Galvanotehnika blagorodnih I redkih metalov/Leningrad" 1970 (electroplating of precious and rare metals)

A. Kyle,

A. I suggest that you try to make daguerreotypes without the aid of a brightener in the silver plating solution.

A. For those who want to plate silver on brass or copper the best solution is to use a cyanide silver bath by using a silver nitrate solution and transferring it to silver chloride, which is a white crystal non-soluble in water, then transferring it to silver cyanide by adding a pure free potassium cyanide to the Ag chloride.

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Ed. note: Thanks Elias! The only thing we would add is a note that preparing a cyanide-based silver plating solution is for experienced chemists in properly equipped labs, not for amateurs :-)

A. Hi Greg. Potassium silver cyanide or sodium silver cyanide is certainly the most popular and robust. But these are horribly toxic chemicals. Please get to a library for a plating text -- the formula has been the same for a hundred years, but at the least you should read about the most obvious hazards like hydrogen cyanide gas. You also should recognize that bright, robust, functional electroplating is a different thing from the plating that is demonstrated in high school chemistry lab. Using an old ring as your anode instead of high purity anodes will probably prove problematic.

You can buy a non-cyanide process with less toxic but proprietary complexers from suppliers like Zinex or EPI / Electrochemical Products Inc. [a finishing.com supporting advertiser]. Make sure whatever you buy isn't cyanide based. Good luck.

Regards,

A. Hi, Keith.

The finishes that look like silver plating are in all probability actually silver plating. Silver is very "white", usually slightly milky compared to other plated "white" metals like nickel (slightly yellow), zinc (not fully bright), cadmium (inappropriate), chromium (blue-ish), or rhodium (dazzlingly bright, too bright).

Almost all practical silver plating is done from silver cyanide plating baths, and cyanide is a deadly poison. You can absolutely do electroplating yourself, but it really should be in a dedicated shop, not in a kitchen, basement, or residential garage. You should be trained in hazardous materials management, and you should be registered and permitted by the authorities who regulate plating activity in your locale.

As you probably know, silver tarnishes. To keep the problem manageable, in addition to silver plating you will need some sort of anti-tarnish post treatment--whether it be a chromate dip (probably not a good idea for musical instruments), rhodium plating, an organic tarnish preventer, a clearcoat, or whatever. You will probably need buffing capability and plating pre treatments as well.

If I was restricted to one single book, I think I'd pick the Metal Finishing Guidebook and Directory, but you'll find several other choices listed on our "must-have" booklist.

Good luck!

A. Dear Keith!

Today exists several cyanide free silver plating proprietary products (3 on USA market).I am sure that somebody in France produces or sells that type of plating bath. You can even make yourself that type of bath (several good formulations exist, some of them are known even in 19th century/ferrocyanide bath and sulphite based bath). I have worked with ferrocyanide based bath over ten years and I can only say that it is simple to prepare and safe and if you work carefully results are very good.

Good luck!

A. Ferrocyanide silver plating bath:
200 gm potassium ferrocyanide [affil links]
20 gm potassium carbonate
40 gm siver chloride
1 lit water
stainless steel anode, 60-80 °C temp.

Dissolve ferrocyanide in boiling water, when it is dissolved add carbonate and when it is dissolved add silver chloride.Boil 1,5-2 hours, filter when cold. This bath can be used for plating and electro forming. For bright plating you can add up to 0,03 gm/lit sodium thiosulphate [on eBay or Amazon] . Keep it in dark bottle. Never mix bath and strong acids! -- according to V.I.Semerjok, from Ukrainian book "Galvanotehnika blagorodnih I redkih metalov" (Electroplating of precious and rare metals)

Many thanks for the formula - once I've finished reading the book and seen more or less how to approach the task from a safety point of view I'll get down to trying it out.

Thanks again

Keith

A. Hi, Alan. I'm confident that it is cyanide-free. I'm less confident that the color is "spot on" because the largest manufacturer of cyanide-free silver plating solutions markets them for electronic use, saying the color isn't quite perfect for decorative use. But if you are doing a few random items, rather than thousands that must exactly match, it's probably good enough.

Remember though, that although cyanide is dangerous, cyanide-free does not quite mean "no concern with respect to toxicity" and "truly safe". Best of luck.

Regards,

Hi, Dwight.

It's probably real silver plating, as always, but with a higher technology and more-effective clear coat replacing the traditional lacquer. If you look at today's auto headlights, nearly all are the plastics as yesterday, but they no longer scratch and craze because of super-hard radiation-cured clear coats. I am not involved in musical instrument manufacturing, but suspect that similar coatings are used.

I wouldn't call the bright instruments better, it's a matter of taste. An outstanding local saxophone player's instrument looks almost brown with age rather than brassy.

Regards,

A. Hi Riccardo. Somehow you must find out whether you have nickel plating or silver plating, as they will be quite different, silver requiring stripping of the lacquer and nickel requiring activation after polishing. Your steps seem okay, but the step I'd be most concerned about is deciding what to plate. You need to acquire some plating experience plating scrap & junk before you try to fool around on something large, useful, and valuable like your tuba.

Luck & Regards,