hammer shapes and symmetry

[Delwin D Fandrich]

----- Original Message -----
From: <A440A@aol.com>
To: <pianotech@ptg.org>
Sent: May 31, 2003 4:12 AM
Subject: Re: hammer shapes and symmetry


>
>     This whole concept may be more applicable to the earlier hammers I
find
> on older STeinways.  In spite of being told that hardener has ALWAYS been
used,
> I have cut and filed way too many original Steinway hammers from the
'20's
> and '30's to believe it.  Many of those old sets don't appear to have had
any
> hardener in them, at all.  The felt was also harder in the middle of the
hammer
> than what I see today.  If this is so, then the egg-shape allowed a
mechanical
> graduation of density that rapidly softened as it approached the strike
> point.

I agree, Ed. The early to semi-early Steinway hammers I worked on when I
was starting out in this business did not show evidence of any kind
hardening solution anywhere in the working part of the hammer. (I refer
here to pianos made prior to, say, 1950. Steinway pianos made during the
1960s and 1970s were already being rather heavily 'juiced'--though not so
much as what we're seeing today.) I think this statement--"they have ALWAYS
been juiced"--can only be justified by including the so-called
"reinforcing" solution--what was it they put in the shoulders? potassium
something or other--as a hardening solution. At the time, of course, this
solution was put in there primarily to give the felt a better gluing
surface and had little, if any, affect on the working portion of the
hammer, but that's another story.

Hammer makers of the time started with a much lower density felt and kept
it that way. They did not steam it to make it moist and they did not press
it in highly heated cauls.



>    It is plausible that the deformation of the hammer under a strong blow
> would flatten out this strike point, so I wonder if the egg-shape allowed
the
> more efficient production of the higher partials under soft play?  ie,
if it has
> a small contact area when played softly, there are less higher partials
> cancelled out by the "footprint" on the string, creating a more complex
spectrum,
> even though the softness favored the fundamental.

That is certainly my theory. And, to expand on it just a bit, this shape
needs to be put in at the press. It is not the same at all to sand the
hammers to shape after pressing. This, I believe, is where the process
started to go bad. Those early hammers came from the press with pretty much
their desired shape inherent to the hammer. Later as presses changed it
became necessary to sand the hammers to shape. I think also, their
"desired" shape changed some. Later hammers became decidedly more pointed.
Most of the felt sanded off came from the upper shoulders--the 10:30 and
1:30 areas. This leaves the felt layers up toward the crown unsupported.
Initially the sound can still be quite good but as the hammers repeatedly
impact against the strings the outer, unsupported layers across the strike
region starts to break down and begins to act as "dampers" against the
felt. This is when the lacquer is introduced. It acts to harden the whole
hammer and glue the now-loosened felt fibers back together.

I came by this observation, actually, at the Steinway factory in the
mid-1970s. I was there, kind of wandering around, for a full week. I was
able to observe pianos go from having a raw, but potentially wonderful,
sound just before pounding deteriorate to dull thudders after pounding. The
only thing that would bring them back up was to sand off the top layers of
felt--spoiling that nice shape--or applying a liberal quantity of juice.
The solution of choice was the solution. But the sound was never the same
again. The dynamics were lost in the solution. (Sorry about that...)



>     On a lacquer soaked hammer, there seems to be little difference in
the
> tonal range due to shape.

Sadly, considering what has been lost, I agree.

Del