Brash Failure

[Joseph Garrett]

Pierre asked: "Also, the case is warped due to the string tension (as most old squares of that time) Could  this be a good reason to keep the pitch lower ?
Is there something that can be done to rectifie this warpness ?"
 
Thanks
Pierre ,
Since most Square Pianos of this period have "Cheek Lift", due to the fact that there was little or nothing in the way of bracing, i.e. a plate or derivatives thereof. The makers knew it would happen, so they oriented the wood grains, etc., to, (hopefully), off-set this phenomonon. (Look at the wood orientation on the bottom of the instrument.<G>) Most did not have the legs attached to the bottom of the piano, but rather, had a separate framework that the instrument sat on. This allows for shimming to be done at the frame/piano bottom, to keep the instrument from "rocking while playing".<G> The only downside to this, is that many times the action cannot be removed from the piano unless the tension is let down! Also, regulation kinda goes to hell with the Cheek Lift. However, these instruments, at their best, didn't play worth a darn, as the actions were crude and Single Escapement types. If the piano is breaking strings at a lesser pitch than 425cps, then you can bet that the wire is shot and needs to be replaced. Gee, it's only 200 years olde, why would it be shot?!!![G]
Regards,
Joe Garrett
De : pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] De la part de Joseph Garrett
Envoyé : dimanche 20 août 2006 18:28
À : pianotech
Objet : lRe: Brash Failure
 
Pierre said: "A small Erard Square from 1804 that I?ve been restoring this year (with the 
original sound board) has a nice tone and a long sustain."
 
Hmmm? Because these instruments have a very low tension, the "tone" will be "nice" to your ear, IMO. Define "a long sustain",please. Most instruments of that period had little or no sustain, in my experience.
I meant  a singing and clear tone (also in the upper treble ) Compared to our 5 years old Walter copy (pianoforte) the sustain is clearly better.  A long sustain is not a good definition, sorry, I meant that the sound lasts for a certain time, enough to give a singing tone. 
"It is a verry small soundboard and the string pressure moved the board
downward causing a dip around the bridge."
 
That is definately a "failure" of the wood. Especially, since those instruments had/have little or no downbearing to begin with, in my experience. The 1805 Clementi, that I care for, has a much worse soundboard scenario....it is buckled in the "killer octave" area. It has almost zero sustain and is pretty "thumpy". Definately  failure of wood structure, IMO.
 As<the depressiojn in the soundboard is quite deep it must have had downbearing when de board was new. The string coils are still at about 1 cm from the pinblock.
"Except for this the piano was remarquably well preserved (wich is not often
the case) and I suppose for that reason that the is still good enough to
produce a good sound. (the piano is tuned at 390 hz)"
 
Again: Hmmmm? I'm curious why you are tuning this instrument @ 390cps? For that time, in Paris, (which was the mecca for Erard), most pitches were in the 400cps to 443cps range? I would have chosen 425cps as a pitch that would put the instrument close to it's designed pitch/tone and yet not overstress the structure too much. What you are hearing @ 390cps is NOT the true sound of the instrument, IMO.
Regards,
 This piano was about 7 steps from 440 hz and I’m not shure but I think these are the original strings. I’ve pitch raised it in about 10 passes until I started to break strings 
I know it should be tuned at at least 425 but it realy sounds good at this low pitch. (mabe I’ll continue to raise the pitch gradually to 425 hz later but am not shure wheter this will have a big change in tone like in a similar pitch raise in a modern piano)
Also, the case is warped due to the string tension (as most old squares of that time) Could  this be a good reason to keep the pitch lower ?
Is there something that can be done to rectifie this warpness ?
 
Thanks
Pierre Gevaert
 
Joseph Garrett, R.P.T.
Captain, Tool Police
Squares R I
 
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