Grand Rim Construction

[Delwin D Fandrich]

----- Original Message -----
From: <ANRPiano@AOL.COM>
To: <pianotech@ptg.org>
Sent: May 10, 2000 5:17 AM
Subject: Re: Grand Rim Construction


> In a message dated 5/10/00 7:06:21 AM Central Daylight Time,
nhunt@jagat.com
> writes:
>
> << 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 no
>  evaluatable.
>
>  In light of the above I would appreciate your thoughts on such a
>  construction.
>
>         Newton
>   >>
> I would like any comments about "built" rims for lack a better word.  I
once
> had two late 19th century Webers in my shop side by side the same piano
> except for one had a bent rim case and the other had a built up case.  The
> latter sounded much better.  Just looking for any thoughts on the matter.
>
> Andrew Remillard

---------------------------------------------

'Built-up' or 'stacked,' I've heard both terms used to describe these rims.
It would be interesting to examine two otherwise identical pianos using
these different rims.  Unless you carefully remanufactured the two using
identical soundboards, scales, hammers, etc, I'm not sure how much of the
difference you heard between the two could be directly attributed to the
rim.

Having said that I should point out that Kawai has used these rims in some
of their pianos -- including, according to Don Mannino, some of their
high-end concert grands -- until fairly recently, and may still use them.
(There is a wonderful picture of this type of rim in one of their marketing
booklets from the early '90s.)  I doubt they would do this if there were a
performance penalty.  I am just finishing up a 6'+ (approx. 185 cm) Geo.
Steck grand having a rim of this type.  I don't yet know what the high
treble is going to sound like, but the bass and mid-range is excellent.

The only problems I have encountered with these rims are those related to
wood movement and glue integrity.  Unless the outer veneers are fully
compatible with the expansion and contraction rates of the rim stack they
can develop longitudinal cracks.  And I have encountered several of these
pianos in which the glue holding the stack together had begun to fail.
Depending on where this failure takes place, it can be some difficult to
repair without removing major structural components.

Again, if the wood used is of sufficient stiffness and density -- my Steck
uses oak -- there seems to be no reason why these rims should not work as
well as laminated rims.  I would think they would be more expensive,
requiring somewhat more labor and using somewhat more expensive wood.  Using
solid wood would be somewhat more costly and wasteful than using veneers.

It would be interesting to compare otherwise identical pianos.

Del