Sorry, but I still believe that rims aid soundboard integrity!

[Delwin D Fandrich]

----- Original Message -----
From: "gordon stelter" <lclgcnp@yahoo.com>
To: "Pianotech" <pianotech@ptg.org>
Sent: July 21, 2003 4:50 PM
Subject: Sorry, but I still believe that rims aid soundboard integrity!


> Respectfully, Ron, these are two separate points, are
> they not?
>     Yes, a soundboard ( when built ) MAY support a
> full load without a rim. And this, I am willing to
> believe, can be amply demonstrated in the shop. But
> to presume that a board with no rim holding it inward
> would resist the downward pressure of strings, replete
> with climate variations, OVER TIME is just that -- a
> presumption.

If I may--presumptions can be based on guesswork and fantasy or they can be
based on a knowledge of a few basic principles of engineering and the known
(and thoroughly tested) characteristics of an engineering material. At
least some of these characteristics are described in my several Journal
articles on wood as an engineering material and those on soundboard
problems several years back.

One of the most welcome changes that has taken place in our understanding
of the piano and how it works over the past several decades has been the
introduction of basic wood technology into a subject that had generally
been filled with mystery and misunderstanding.

So, yes, accurate predictions can be made about the longevity of a
soundboard panel as long as those predictions are based on the known
physical and mechanical characteristics of the material involved--in this
case spruce wood. In this case, yes, accurate predictions can be made about
how a soundboard panel will react over the years with or without the
supposed benefit of a piano rim.

This is a sometimes difficult transition folks to make--even now when I
give classes on the idea of treating wood as an engineering material devoid
of its mystery there is still some residual criticism. There is still a
strong desire to keep wood in the mystery category--it is a natural
material coming from a living organism, after all, and we want to hang on
to the mystery. But in reality wood is simply a fiber-reinforced plastic;
an engineering material. While its characteristics are variable and complex
they are still quantifiable, measurable and predictable.

Del