Shellac vs. lacquer

[David M. Porritt]

This has been an interesting thread.  As a proponent of Renner Blues,
I'm amazed at the gyrations one goes through to make NY S&S hammers
useable.  All the different concoctions from Collodion & ether,
lacquer, plexiglas, sanding sealer, keytops and shellac (have I left
any off?) to make a hammer what it's supposed to be.  I've done it
and it isn't fun.

I find I can get the sound I want -- and more importantly the sound
the pianist wants -- with the Renner Blues doing just a very small
fraction of the work that's been talked about in this thread.  I
realize that all this has to do with our personal preferences and
what we get used to.  I also know there's no right or wrong about
this.  I just prefer hanging Renners and taking an hour or less to
make them what I want.  I'm probably just lazy!

dave

*********** REPLY SEPARATOR  ***********

On 7/17/02 at 3:40 PM David Love wrote:

>Bill:
>
>I am still inclined to opt for the higher density explanation.  When
you
>compare a NY Steinway hammer to a Renner or Abel hammer, it seems
unlikely
>that you would find a different in the stiffness of the individual
fibers
>accounting for their tonal difference.  When inserting a single
needle into
>each hammer it seems that the difference in felt density is evident.
 Abel
>and Renner achieve that difference through the use of higher density
felt
>to
>begin with, perhaps, plus the application of heat during the
manufacturing
>process which shrinks the felt down to a denser mass.  You can see
this
>when
>you needle the hammers and the hammer expands.  You can also achieve
a
>louder or brighter tone on one of these hammers by soaking the
hammer with
>acetone.  Presumably this doesn't stiffen the fibers, but causes
some kind
>of shrinkage which, again, makes the hammer more dense.  Moreover,
you can
>brighten the tone in a NY Steinway hammer by ironing the felt.  It
is hard
>to imagine how this would stiffen the individual fibers.  It seems
more
>likely that it compacts the felt at the crown: more density equals
brighter
>sound.
>
>The fact that certain hardeners "break down" seems more a function
of how
>deeply the hardener penetrates.  If it lies on the surface or crown
of the
>hammer, then as the surface wears away with playing so does the
hardened
>felt.  This process is complicated by the fact that the same playing
that
>wears away the densified felt also packs the felt down underneath.
So
>sometimes a little bit of hardening of the crown is a nice temporary
>measure
>until the hardener is worn through and the natural compacting of the
felt
>takes over.
>
>It seems that what many of us are looking for is a hammer which is
somewhat
>more dense than a NY Steinway hammer and somewhat less dense than a
Renner
>or Abel hammer.  One interesting experiment might be to take a NY
Steinway
>hammer, infuse it with an alcohol and water solution and throw it
into the
>drier for an hour to see if that doesn't brighten it up.  I, for
one, would
>be happy to come up with a way to get a NYS style hammer more dense
without
>lacquer.  Lacquer is tricky and unforgiving in some ways.  I find
that when
>trying to build up the hammer from scratch it is important to select
the
>right solution for the first application.  Since densifying the felt
>usually
>needs to be done at the core of the hammer where the felt is already
the
>most dense, applications of lacquer tend to seal the felt from
further
>penetration by subsequent applications.  You don't get the same
effect by
>multiple applications of weak solution as you do from a single
application
>of the right solution.  The lacquer has a tendency to build up
outside the
>core.  Rather than a graduated density, which I think is desirable,
you can
>end up with a hammer that is hard on the perimeter but not
necessarily at
>the core.  Applying lacquer from the side of the hammer helps in
this
>respect.  On the other side, you can overdo it and apply to heavy a
>solution
>which can glue everything together and rob the hammer of necessary
>resilience.
>
>David Love
>
>----- Original Message -----
>From: "Bill Ballard" <yardbird@pop.vermontel.net>
>To: <pianotech@ptg.org>
>Sent: July 16, 2002 9:21 PM
>Subject: Re: Shellac vs. lacquer
>
>
>As I understand it, reinforcers do three things, one after the other
>depending on the dose. First they coat the fibers to slow them down,
>thus dampening their elasticity. Next they glue adjacent fibers
>together, where these are close enough to have their gap bridged by
>the resin, again hobbling the felt mass's natural elasticity. And
>third, and most disastrous, they fill in the air space within the
>felt mass.
>
>I think David, we have a similar vision of what's happening inside
>the felt mass. I don't think that the density of the hammer changes
>significantly until the dosage has done the first two stages, and is
>turning what used air space into solid resin. That's when the
>compressibility is non-existent. (There is no air space in which the
>compression can occur.) In the first two stages, I don't think the
>amount of solids is enough to affect the density of the felt mass.
>But the flexibility of the felt mass is nevertheless affected.
>Coating the fibers, and gluing them together at point of adjacency
>will definitely stiffen the felt mass, requiring more force to get
it
>to compress.
>
>All this talk of embalming hammers would lead one to wonder why
>anyone would ever want to dope a crown. Well, with NY Steinway
>hammers, unless your pianist likes their piano warm and fuzzy, it's
>inevitable. You can firm up the shoulders all you want, even
>including under the strike point. But the hammer and the string are
a
>pair of springs, and the best sound comes when the reach their
>maximum deformation simultaneously. Power and projection from a NY
>Steinway hammer will not emerge until the strikepoint fibers have
>been stiffened (and their bending under force slowed). And if I'm
>obliged to stiffen, I'd like to stiffening resin to have its own
>elasticity to contribute to the hammer/string event.


_____________________________
David M. Porritt
dporritt@mail.smu.edu
Meadows School of the Arts
Southern Methodist University
Dallas, TX 75275
_____________________________