 The Clarinet BBoard
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Author: SeAn
Date: 1999-05-09 00:45
I wonder if anyone has this experience.
hard rubber material of the mouthpiece cause tarnishing on the silver-plated keys.
My RC's silver keys (LH B, C and C#) nearest mouthpiece turn purplish blue a week after I place my new Morgan next to it(in the case). even the barrel rim "caught" it and turn to a slight reddish tint. from then on I keep the mouthpiece back in its container.
-is it true that hard rubber has an effect on certain metal(like silver)?
-how abt the reverse, metal's effect on hard rubber. have seen some rubber mouthpiece turn greenish" in colour.
-is there any way of rectifying the change? short of replating.
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Author: Mark Charette
Date: 1999-05-09 03:05
If the rubber has a high sulfur content (from vulcanizing) then the tarnishing would be pronounced. Your mouthpiece must be made from one with high sulfur content.
The green appearance of old mouthpieces - I don't know. Possibly from the slow evaporation of volatiles in the original rubber?
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Author: Dee
Date: 1999-05-09 14:01
Mark Charette wrote:
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The green appearance of old mouthpieces - I don't know. Possibly from the slow evaporation of volatiles in the original rubber?
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I have gotten a temporary greenish tinge when wiping them down with alcohol to disinfect old mouthpieces. It does seem to return to the normal color eventually. Also, the sun will affect them. I have an old Albert clarinet. The entire thing is made of hard rubber and has changed color to a brown with a very slight hint of green to it. The bore has remained black as well as the portion of the mouthpiece under the ligature.
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Author: Don Berger
Date: 1999-05-09 16:15
Sometime back on the Early Clarinet site [Onelist], the subject of hard rubber was discussed at length. Yes, H R is heavily vulcanized [with sulfur, sometimes as lead sulfide -PbS], so its not surprising the S transfers to tarnishable Silver by contact or even by vapor. The greening is probably surface decomposition [at a very slow rate] and may be due to metals such as copper contained in the old natural rubber or the sulfide used. So much for chemistry. The green-brown mps are oldies, possibly goodies!! Don
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Author: Hiroshi
Date: 1999-05-10 02:06
Yes,my Frank Kasper-Cicero MP was greenish and a goody!
I read in this BBS that someone posted there is a 3M product,maybe called '3M anti-silver strip',which absorbes Sulfur contained gases inside cases.
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Author: Don Poulsen
Date: 1999-05-10 14:02
A while back a post on this bulletin board noted that one should not use rubber bands for emergency repairs on silver plated instruments because of possible tarnishing. I posted back that it made sense because of the sulfur used in the vulcanization process. However, I never made the connection with a hard rubber mouthpiece! This may explain why the inside of the silver-plated mouthpiece cap on my new instrument has begun turning a bronze color, but the effect on the rest of the silver plated parts has not been nearly as pronounced. Perhaps I should keep my mouthpieces isolated from the rest of my instrument, including the cap and ligiture, when it is not in use and save the cap for protecting the mouthpiece and reed when they are out of the case. (This may also explain why the mouthpiece that came with the instrument was in a reusable plastic screw-together tube.)
Any thoughts?
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Author: Don Berger
Date: 1999-05-10 14:54
Yes - the variety of observations re: sulfur tarnishing is interesting. I believe that the more recent developments in hard rubber technology has led to fewer problems re: tarnishing, and greening, prob. due to more efficient crosslinking of the newer synthetic rubber molecules with sulfur atoms. Re: rubber bands, unless the silver surfaces are "plastic-coated" [sprayed] most any color bands will leave a mark [overnite] and also will extract oil from a wood cl leaving a light-colored track, but I still use rb's to help seat new pads and re-oil the marks,have fun, Don
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Author: Fan
Date: 1999-05-10 17:50
Yes there is something call "3M silver polish strip"
which Stephen Fox put in my box after he overhaul my
R-13. I wonder is this used to absorb the sulphur ?
do not use it to polish the key as it will scratch it :<
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Author: Don Berger
Date: 1999-05-10 19:24
Correct - Just ask the housewife how she fights tarnish of sterling [or plated ] silver [Ag] flatware. Its an old problem with many ?solutions? how to absorb [or adsorb] atmospheric sulfur dioxide [SO2] and/or hydro-sulfides [H2S, the rotten egg smell, also ethyl mercaptan C2H5SH, the usual natural gas odorant]. Except for my Selmer alto cl, whose keys appear to be plastic-sprayed, but somewhat slippery!, all of my horn's keys are of good old nickel-silver, which only turn light gray!! Enough chemistry? Don
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Author: Ben
Date: 1999-05-11 00:45
It seems that nickel might have a reaction with sulfer too.
I've been using a rubber band to replace a spring on an old metal clarinet. A black deposit developed after about two weeks of direct contact.
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Author: Don Berger
Date: 1999-05-11 02:58
Possibly, Ben, but nickel is much less reactive than silver and copper, both of which form black sulfides. Likely your metal cl [and keys] are silver plated, and being old had "dulled" with a thin surface coating of silver oxide, so that when exposed to [the low] rubber band vulcanization sulfur, it took some time for the AgS to form. A hypothesis, no less! Don
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Author: Donn
Date: 1999-05-12 13:41
Seems like I heard many years ago of using mothballs in a closed container with silverware to prevent tarnish. Anyone
heard of this? Do you have a chemical explanation for this, Don?
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Author: Don Poulsen
Date: 1999-05-12 13:53
I'm not the Don that you're asking, even though I know a little about chemistry. I assume that your question regarding mothballs in a closed container is completely academic because there was a recent thread about pad bugs in which one poster alerted us to the toxicity of moth balls and warned against putting them in our clarinet cases.
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Author: Don Berger
Date: 1999-05-12 16:27
Glad there are more Don chemists, [actually I'm a ChE, a plumber who knows {only} a bit of chemistry]. To my knowledge, the "old" mothballs are naphthlene [a higher MW aromatic than benzene] which is a vaporizing-solid at room temps. The "newer" mb's are a chlorinated hydrocarbon, I think, I'll look the structure if anyone has that much interest. I doubt either would be good in an inst case. For me, sunlite exposure now and then is sufficient to fight smells and bugs.
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