A string's treatment

[Isaac OLEG]

Stephen,

Thanks for your detailled point and explanations.
I noticed something in the tone of those Shimmels, which a re supposed
to use the process.

Yes the method is a little oversimplified, I understand you say it
works but not in the good direction.

At last someone have a good point of it.
Then, may be you also are missing something there.

As I said, the methopd have been developped by Klaus Fenner (doe not
mean it is a good solution), and given to me by another Stephen you
may know

I'll answer later, after having checked the points expressed.

Pesonally I should not say so but I am not found of the tone of
Shimmel. I recognize their quality and strongness of making but there
is some sort of strange brillance in their tone I have to ask if they
have been using the process and for how long.



I am very happy you answer me with your facts, - it was in fact
exactly "what I expected" I am not enough instructed in molecular
changes in piano strings that I can make up my mind easely on those
things.

On the other hand, if an interesting method exists if may be valuable
to some.

On concert instruments, the tone is generally too "green" during the
1 or 2 first years, then it settle, but still an instrument which is
maintened to standard pitch need much PR and tunings during its first
years. After 5 to 8 years it can begin to break strings often if too
much PR.

Having better toning is always the intention at last.



Best regards, I'll write later


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> -----Message d'origine-----
> De : Stephen Birkett [mailto:sbirkett@real.uwaterloo.ca]
> Envoye : mercredi 9 juillet 2003 07:01
> A : oleg-i@wanadoo.fr; Pianotech
> Objet : Re: A string's treatment
>
>
> Isaac wrote about wire:
> >I come back with this post that you may not have noticed. It is a
> >prcocess to produce some sort of annealing on new strings
>
> well no, not  annealing which is done by heating the wire. The
> process being used here is a mechanical manipulation.
>
> >if you want the strings to sound more brillant, may be they may be
> >aged (other strings as well)
>
> Sounds like cheese or wine-making, not wire-making... I don't like
> the method for music wire as described. Presumably, the
> procedure is
> being applied to raise strings past their elastic limit but
> below the
> ultimate tensile strength (uts). This would tend to enhance
> stability, but only if the working stress on the wire is
> too close to
> uts to begin with, either because of bad scaling or bad
> wire. And the
> result is a second-rate tonally-poor wire in my view.
>
> Isaac, methinks you had a song and dance from your
> wire-maker friend
> about this, or at least whoever told the original story is playing
> fast and loose with the metallurgical facts with a dash of
> salemanship thrown in. There is some basis in reality but
> not a good
> one in my view.
>
> The tensile properties of high quality music wire should
> be: (1) high
> uts consistent with desired working stress, (2) yield point
> as close
> to uts as possible, and (3) sharply defined transition to plastic
> deformation. It's quite difficult the make wire with all of these
> properties - modern patented high carbon steel music wire is a
> marvellous product that is too often taken for granted. If you look
> at something like Roslau wire you get a yield point of
> about 2200MPa
> with UTS of 2400MPa [these values are typical]....yield may begin a
> bit lower, but the sharp dive is around these typical values. There
> is no room in that tensile curve for the sort of "conditioning"
> described, so whoever is doing it is using bad wire to
> begin with. It
> is  undesirable anyway to stress wire beyond its yield point - this
> does  raise the yield point to some new value closer to UTS, and in
> fact the deformation is actually almost instantaneous, so
> there is no
> need for the hours of sitting of original yield point, if you did
> want to do this. Why undesirable? Well, in my view, the sort of
> "brilliance" you could achieve this way is metallic, almost
> unpleasant - plastically stretched wire is metallurgically quite
> different from drawn wire. I can see why it might be resorted to in
> some cases, for instance if the wire product being used is not
> properly drawn as music wire, and yield point is too low in
> relation
> to UTS [but the result will always be second-rate]....this is the
> problem with all Rose wire for instance. Or I can see it being
> resorted to because of a bad scale with working stress too close to
> yield point, but not really a good solution. Better to use better
> scaling more appropriate to the wire product being used. I can also
> see it being used as a bandaid solution to fix wire which has a
> shallow transition to plastic zone from elastic, instead of the
> desirable sharp transition, as I expect is the case with many
> subsitute "low tension" wires [although I haven't tested many of
> these wire types yet]. In all cases it is better to fix the
> problems
> at either the design level or the wire product level, rather than
> tinkering with the mechanical properties of the wire by
> stretching it.
>
> >comments welcome.
>
> Hmm. Not sure I said what you were hoping to hear Isaac....
>
> Stephen
> --
> Stephen Birkett Fortepianos
> Authentic Reproductions of 18th and 19th Century Pianos
> 464 Winchester Drive
> Waterloo, Ontario
> Canada N2T 1K5
> tel: 519-885-2228
> mailto: sbirkett[at]real.uwaterloo.ca
> http://real.uwaterloo.ca/~sbirkett
>