At 6:13 PM -0500 7/17/02, David M. Porritt wrote:
>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.
It would be a sorry world indeed if all we could breath was steam...
eh, RickyB?
At 3:40 PM -0700 7/17/02, David Love wrote:
>I am still inclined to opt for the higher density explanation.
And I say "tomatoes".
>it seems unlikely
>that you would find a different in the stiffness of the individual fibers
>accounting for their tonal difference.
Agreed. Whatever blend of wool the hammer-felt maker uses will be
quite consistently mixed throughout the sheet and lot. Hopefully
that's what the piano factory is willing to pay for.
>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.
It's very interesting that the Abel factory makes what I. Your Abel
and mine sound very different. I actually consider Brooks Ltd. Encore
hammers to be the closest of perfect, as far as tonal development.
It's nice and warm the first time you play the hammers set, and with
a year or two's playing the tone will bloom without any prompting by
you. And do so in a process of what I call (mundanely)
"work-hardening". The wire continues the felt-maker's fulling
process. In this process, the panel of felt is bashed on its
end-grain sides, and the fibers further entwine and hook together at
interlocking platelets. The population of individual fibers is now
untied as one integral spring. This work-hardening is the kind
densification which best harnesses the felt mass's elasticity. Most
others damage it.
Note that the fulling does not increase the felt's mass, but it does
densify it. There are two ways in which felt can be densified:
increasing the mass while holding steady the volume (of a solid, not
a sound), or decreasing the volume while not changing the mass. Work
hardening is an example of the latter, as is weighting up hammers.
When you hot-press a hammer, the mass isn't changed but the hammer
gets slightly smaller. This is an example of the first way of
densifying. An example of the second is the weighting up of hammers
for a SW set.
>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.
Exactly why the felt mass would have such a cringing response to
acetone, I would be interested to hear. There have been, BTW, many
fine suggestions from you, Dale and others. This sounds chemical,
although not to be overlooked is the condensation of water vapor
occurring on a small scale, cause by the flashing off of acetone.
>Moreover, you can
>brighten the tone in a NY Steinway hammer by ironing the felt.
Localized thermoplastic reshaping.
>It is hard
>to imagine how this would stiffen the individual fibers.
It doesn't. It simply means that however the fibers were deformed by
the collision with the string, they will now take that shape and make
it their neutral point of their elasticity.
>It seems more
>likely that it compacts the felt at the crown: more density equals brighter
>sound.
More dense means that the felt mass contains less air space with
which to collapse. In the collision with the wire, the gradient
between the strike point felt's static texture and its "hit the
bedrock" wall is very steep. Think Horowitz (his hammers, not his
sound)
Who saw David Stanwood's photo micrographs of a "Nu-Tone" and a
Ronsen hammer felt so tat the fielt fibers looked like palm tree
trunks? back in the early 90s?. The Nu-Tone had hardly any interior
air space to allow any squashing and rebounding. The Ronsen had the
airspace of a stack of cordwood.
I think mass is a significant determinant, but I also think that
density is the enemy of elasticity. I tend to imagine the hammer mass
as a muscle (with the molding, the bone). Who need to be muscle bound
, you can't move a muscle?
That's why I follow the trail of elasticity . Mass (and by
definition, density) can be added to without increasing the solid's
volume. What can't be restored once damaged, is elasticity. That's
why I am concerned by anything while damages the "aliveness" of this
muscle.
>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.
I like that very much. You great a tough hide with which to spread
the compacting effect of the wire over as large an area as possible
(not simply the string groove), and after a year or so of generalized
compacting, you remove the hide and begin to work with the
well-formed muscle underneath). Muchos Thanquos!
At 3:40 PM -0700 7/17/02, David Love wrote:
>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.
Wally Brooks and Abel have just about got it right, IMHO.
At 3:40 PM -0700 7/17/02, David Love wrote:
>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.
Are you talking raw or reinforced? I'd be more interested if the
water content had say, an unaccelerated 24 hours to do its work.
At 3:40 PM -0700 7/17/02, David Love wrote:
> Applying lacquer from the side of the hammer helps in this
>respect.
I would think poring it in from the sides would be just the thing to
give the felt mass a firm foundation. I was surprised that it seemed
not to make a difference in the focus of the sound on two Ls this
spring. It would seem eventually the strike point will have to be
reinforced.
Boy, I learned something good tonight!
Bill Ballard RPT
NH Chapter, P.T.G.
"No one builds the *perfect* piano, you can only remove the obstacles
to that perfection during the building."
...........LaRoy Edwards, Yamaha International Corp
+++++++++++++++++++++
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