treble wire breakage

Stephen Birkett sbirkett@real.uwaterloo.ca
Wed, 1 May 2002 16:18:03 -0400


Joe writes:
> Either you haven't been paying attention or the ears are going. <G> The Olde
> wire has just spent the last 100years stretching/elongating/being
> contaminated by god knows what and you say the treble strings do not
> DETERIORATE! BS, they do and everyone who knows, knows that. Sheesh, where's
> your reason, man? 

Well this depends on a variety of factors. A string operating well into
the elastic zone (i.e. far enuf from the plastic region), as it should be
for a modern piano scale with high carbon steel wire, will undergo only
elastic deformation, even with very hard playing.  I've seen enuf 19th
century pianos with perfectly good >100 year old treble strings.

The wire may of course deteriorate for other reasons: (i) environmental
contamination - which is a particular problem for carbon steel wire, and
may kill the wire quite prematurely - or (ii) design flaws which introduce
stress that exceeds the elastic zone at critical points like bridge pins,
agraffes, tuning pins etc, or (iii) design flaws that provide a scale too
close to the plastic zone. I suspect that reasons (i) and (ii) are likely
to be the cause of most breakage of modern piano treble strings.

Now, going back another 100 years, you have non-carbon iron, and reason
(i) tends to take on less significance. The stuff is remarkedly stable
from corrosion etc. Reason (iii) is a function of scale design - the high
quality builders knew how to keep their wire well away from the plastic
zone. Schiedmayer talks about this and discusses the certain end of a wire
that goes plastic,a nd the critical necessity to avoid this in scale
design. For these old olde strings I would expect reason (ii) to be the
most likely cause of failure. Even so, I've seen pre-1800 iron wire that
would work perfectly well as treble stringing material.

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@real.uwaterloo.ca 



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