Grand Rim Construction

[Delwin D Fandrich]

----- Original Message -----
From: Newton Hunt <nhunt@jagat.com>
To: <pianotech@ptg.org>
Sent: May 10, 2000 5:49 AM
Subject: Re: Grand Rim Construction


> > First, you have to define 'superiority of sound.' The Select Hardwood
rim is
> > neither as massive nor as stiff as is a maple, birch, beech, ash, oak,
etc.,
> > rim.  This means it will absorb somewhat more of the vibrating energy
within
> > the soundboard--energy that would otherwise go into sound energy.
> >
> > If all other elements of the design were the same, sustain would be
> > noticeably (and unacceptably) shorter in a piano using Select Hardwood.
I
>
> Del, I once saw a piano with a concrete rim.  Yeah, that's right, a molded
concrete rim.
> The "piano" part was junk so quality was not evaluatable.
>
> In light of the above I would appreciate your thoughts on such a
construction.
>
> Newton

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I have heard about these but have never seen one.  Aside from the obvious
difficulties in making them, they would probably work quite well.

Seriously, they probably could be made to meet the acoustical requirements
of a good piano rim.  They would (or at least easily could) be rigid and
massive.  They would not be resonant -- at least not at frequencies that
would bother piano tone production.  The major drawbacks would be the
difficulty of construction and finishing.  Unless the piano were made black,
you would face the difficulty of veneering to a surface that doesn't respond
well to conventional woodworking techniques and/or adhesives.  You could
probably use hide glue but most manufacturers would balk at the time it
would take (by fairly skilled workers) to prepare the surface and apply the
veneers.

I haven't checked the density of concrete relative to maple, but I also
wonder about weight.  The last time I did any work with concrete blocks they
seemed rather heavy for their size.  By the time you got adequate
reinforcing material into the mix to keep it from cracking I'd think the end
result would be some heavy.  I'd also worry a bit about it chipping -- there
is at least one cross-country piano mover you might want to avoid....

And then there is marketing.  I wouldn't even want to begin to sell these
things into a market that seems to value tradition above all else, including
tone and action performance.

Del