As I previously mentioned in another board, last summer (2007), I had a Gemeinhardt M2S which is basically a student model flute (closed hole, C foot, etc.) but with sterling silver tubings and plated keys [and barrel]. The odd thing about the flute was that there was significant pitting on the body (must have been stored somewhere funky or something!) as well as on the plated barrel. The headjoint and footjoint, however, were fine and how the flute's body managed to get pitting is beyond me. Keeping in mind that this flute is 50+ years old (give or take), materials and sterling silver percentages (925 on this flute) are rising in quality as well as degrees (ex. 999 pure silver, etc.). I'm unsure whether or not sterling has to be crudely stored in order to be pitted/pitting however this was my first encounter with a pitted sterling flute EVER!
Luckily I was able to find a folder with photos of the flute's pitting and below are the photobucket links to the previously mentioned pitting. Hope this helps!!
Hi Suzie. I have four or five sterling (Armstrong 90) with pitting. I was in shock. I don't know there history so I don't know why they pitted; however, I do have an Armstrong Heritage (closed hole c-foot) that has two spots of pitting. I took excellent care of this flute its entire life. For the past three years I've had the "silversaver" strips in its case.
I spoke to a silversmith who said there are many reasons for pitting. Here are a few: acid rain (from using the flute in marching band), acid on peoples hands (never though of myself as be caustic but I guess there's always a first time ), then there's the air/enviroment (smog etc). I live in LA California, smog city USA. I remember not being able to see across the street because the smog was so bad when I was a kid. Maybe that's why my flute is beginning to pit.
I have worked on a lot of sterling silver flutes. I have NEVER seen pitting on sterlings silver.
I have seen a lot of pitted flutes. The pitting has always been on plated, copper-based alloys.
Pitting starts as an invisible hole through the plating, because of porosity. Then body (or other) electrolytes get into that hole, and galvanic corrosion sets in, causing the pitting. Galvanic corrosion does not set in unless there are dissimilar metals in (electrical) contact with each other.
So, as I said, I have very high certainty that if you are seeing pitting, then you are NOT looking at a sterling silver product, no matter what you may have been told. And as I said, manufacturers can make mistakes, presumably even with miss-labelling the metal.
As I said, I would not believe it was sterling silver until I had done a heat conduction test, where silver shows up very clearly. BTW, some copper alloys can look very similar to silver.
(Isn't this thread simply a repeat of another thread? Why)
Silver is prone to tarnish, from quite a few different causes, but I don't think pitting of the type shown is caused by anything other than galvanic corrosion.
This needs two dissimilar metals in order to occur.
um, well... i have reason to believe that my sweat is eating away at my flute. i do have hyperhidrosis on my hands and my dermatologist said that the eating away of the wilver is very possible. but is this considered pitting? yes my flute is a solid silver flute. no, the company didnt mismark it. otherwise i will be demanding a refund.
is there any way to stop this whole eating away of my flute? i wipe down my flute a lot, but even after a practicing session, its hard to wipe it down completely because the sweat dries and its almost embedded in the flute (even with a soapy water solution or rubbing alcohol and such).
you could wear see through gloves while practicing, then you are not damaging it during practice, just make sure the gloves are breathabl or else your hands will sweat even more
Perhaps you could investigated which manufactures actually plate with rhodium, or a rhodium alloy, over the sterling. As I understand it,it looks pretty much identical to silver but has far better corrosion resistant properties. (I believe there are other lesser-known metals used also) It is possible that some manufacturers do this, but say nothing, because players generally do not want to hear that their solid sterling flute is plated with silver, or anything else, unless it is gold. Plating with silver over sterling is very common. It gives a slightly better appearance, and hides the otherwise different colour (especially after some tarnishing) of the soldering.
Sterling Silver is "only" 92.5% Silver, so that leaves 7.5% for something else that might be what is pitting. This is just speculation, however, as I am no expert in metallurgy.
"Sterling Silver is "only" 92.5% Silver, so that leaves 7.5% for something else that might be what is pitting. "
I was well aware of that when I wrote my posts.
"You can always get the thing ultrasonically cleaned. It would still have tiny pits, but they wouldn't have the black areas down in the holes."
And then again, that may leave the surface microscopically much more able to accommodate fresh electrolyte, hastening further corrosion.
"Solid silver tends to corrode in an even manner, more like rust. Just as destructive, but usually not as unsightly looking."
Yes, silver tends to corrode evenly, which is why this looks like galvanic corrosion rather than just normal silver corrosion. I would not say it was like rust though, because rust is unique in that it does not protect a surface. It flakes off the iron or steel, and leaves fresh surface to corrode. Hence the corrosion does not stop until the metal has been corroded away.
Galvanic corrosion could be the culprit, as said. Normally, there is the need of two differente metals, in direct contact or in electrical contact through a suitable electrolyte (for example, it could be a slightly wet inner case lining or the cleaning cloth, left wet after cleaning and stored inside the flute cas (as happens with my M3 Gemeinhardt but not with Yamaha).
But still, the second metal is needed and it could be the cleaning rod or other case metal part.
But just the presence of 2 metals is not enough, however.
To have metal ions migrate from the flute into the other metal, (thus causing the pitting on the flute), the silver should act as an anode and the other metal as cathode. This depends on the position of each metal in the Galvanic series (a list of metals according to their electrochemical activity).
Silver is a noble metal and is placed very high on the list, only lower than Graphite, Palladium, Platinum and gold (if the electrolyte is salt water, not necessarily the case in a flute...).
So it is unprobable that silver can act as the anode to suffer pitting from galvanic corrosion in the normal environment of a flute case.
But there is another phenomena, called concentration cell, where a metal can suffer galvanic corrosion against itself, provided the electrolyte varies in concentration. This could well be the cause of pitting on a silver flute.
searching...
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), then there's the air/enviroment (smog etc). I live in LA California, smog city USA. I remember not being able to see across the street because the smog was so bad when I was a kid. Maybe that's why my flute is beginning to pit.
