 The Clarinet BBoard
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Author: Clarineteer
Date: 2012-08-02 15:57
I have found a green turquoise substance present on old clarinet keys that have been sitting in cases for many years that eats into the metal. Does anyone know what this is?
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Author: David Spiegelthal ★2017
Date: 2012-08-02 16:07
Tarnished nickel-silver (a.k.a. "German silver"), a copper-nickel alloy used widely for clarinet keywork. The green color comes from copper oxide. A bit of Brasso or other metal polish will remove it expeditiously.
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Author: Buster
Date: 2012-08-02 21:07
A bit of a tangential question for any repairmen...
On my older clarinets that have been worn down to the nickle-silver base, much of the metal key-work seems to have softened and is quite difficult to keep in good adjustment.
Is this due to the copper "leaching" out due oxidation, or a victim of non-standardized alloy percentages of nickle-silver some 50-60 years back?
The copper content would seem to be a red-herring as it is a soft metal, but perhaps the nickle and zinc content was highly variable in the past as there were no ASTM standards...
-Jason
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Author: David Spiegelthal ★2017
Date: 2012-08-02 21:29
Jason, I've seen a wide variation in the mechanical properties (and corrosion properties) of the metals used in older clarinets. I would go along with your conjecture that there was little or no standardization of the composition of nickel-silver alloys.
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Author: Buster
Date: 2012-08-02 21:59
David (Dave),
Could a 'simple' re-plating of silver or nickle (with a copper "flash") restore some stability to the key-work, or does a softer base metal supersede any re-plating that is done?
It may be a crap shoot, but I'd be willing to give it a try on my *insert name* clarinets if it would improve matters (and be cost effective.)
-Jason
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Author: David Spiegelthal ★2017
Date: 2012-08-02 23:50
Plating is too thin to add any detectable mechanical strength. If the keywork started off 'soft', it will remain soft after plating. It will just be shiny soft keywork instead of dull soft keywork.
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Author: BobD
Date: 2012-08-03 12:06
First of all it is poisonous. The copper in the nickel silver base alloy reacts with oxygen in the air and forms a number of different compounds varying in color from black or red to green or , as you state, turquoise. A common name for the greenish color is verdigris as seen on copper or bronze statues.
Bob Draznik
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Author: clarinetist04
Date: 2012-08-03 17:38
Dave - Is the copper oxide what causes the instrument to smell metallic when an instrument is left to sit for long periods of time? When an instrument is cleaned (and not placed back in the case where the green verdigris has accumulated) will the smell go away?
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