Soundboards: Thickness and Area

[Isaac sur Noos]

Hi

My friend Stephen is not convinced that this is not only marketing
stuff.

What kind of information do you obtain with a plastic hammer ?
The zones where the sand does not move are the zone of firmness of the
board, so it does not have much to do with the elasticity regulation.

Eventually, the knock will give a view of the first resonant mode.

Sanding the tone wood is less good than scraping or working with a
rabbit usually, because of the difference of density of the fiber.

Then , not really easy in real life to put the sand, note the aeras,
vacuum, sand the aeras, put back sand, test, note, vacuum, sand, etc
etc.

Far from practicable approach , I seem to remember he say something
abouth the child playing with the sand ;>).

Stephen use a variable frequency generator on the bridge, while
thinning . This also I am unsure what information it can give out of
the different modes appearing.

Greetings.

Isaac OLEG

Entretien et réparation de pianos.

PianoTech
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94400 VITRY sur SEINE
FRANCE
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> -----Message d'origine-----
> De : pianotech-bounces@ptg.org
> [mailto:pianotech-bounces@ptg.org]De la
> part de Kjell Sverre Fardal
> Envoyé : mardi 21 octobre 2003 00:21
> À : 'Pianotech'
> Objet : SV: Soundboards: Thickness and Area
>
>
> Hi, Richard
>
> The pictures that mr. Steingraeber showed at the convention
> were of a
> soundboard already installed in the piano, with the rim and
> everything.
> He told us that he used a "plastic-hammer" to knock on the
> bridges. He
> also told us that they thinned the board by sanding it.
>
> But it was the last lecture at the last day of the
> convention, so you
> may be excused.... :)
>
> Kjell Sverre Fardal
> NPTF / Norway
>
> -----Opprinnelig melding-----
> Fra: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] På
> vegne av Richard Brekne
> Sendt: 20. oktober 2003 20:03
> Til: Pianotech
> Emne: Re: Soundboards: Thickness and Area
>
> I'll have to check on the specifics. Tho I believe the
> assembly was in
> the piano for the proceedure. Just where and how they thin
> to get the
> desired results, he didnt have time to go into, tho I will
> see if I can
> find this out. Kevin Gouldman is an American builder in Danmark and
> knows Uddo Steingræber fairly well, and I believe he knows very much
> about how the Steingræber factory does this... so I'll ask
> him as soon
> as I can get to it.
>
> Cheers
> RicB
>
> > Erwinspiano@aol.com wrote:
> >
> >    Ric
> >    My first post was incomplete please see other.
> Interesting post.
> > were the boards in or out of the piano/ I presumne in? If
> in then how
> > did the accomplish thinning?
> >    Thanks--Dale
> >
> >      Apprapoe freeing up the edges of the board Dale,
> >
> >      One of the segements of Steingræbers lecture in Helsinki
> >      this past
> >      weekend was about this. He showed a few pictures of how they
> >      go about
> >      this at their factory and breifly discussed some of the
> >      goals in their
> >      proceedure.
> > .............................. snip
> >
>
> --
> Richard Brekne
> RPT, N.P.T.F.
> UiB, Bergen, Norway
> mailto:rbrekne@broadpark.no
> http://home.broadpark.no/~rbrekne/ricmain.html
> http://www.hf.uib.no/grieg/personer/cv_RB.html
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