Hammer resiliency was RE: [CAUT] Steve Brady's book...

[David Love]

You can determine sufficient resilience in part by feel (especially when
preneedling before you even install them you can squeeze the hammers at the
shoulder and feel them start to give after a fair amount of needling) but
mostly by the sound.  Until the hammer gains some reliance it sounds like
the attack gets swallowed very quickly.  When there is sufficient
resiliency, the tone will open up.  I'm surprised to hear the he needles
below the staple to gain resiliency.  Needling down that low will actually
release tension toward the crown and firm up the hammer somewhat.  It is an
effective remedy when you have slightly over needled a hammer.   Andre O.
has referred to this as "battery voicing".  It does work.  There is a
limited amount of reserve down there though so it's best not to tap into it
unless you have to.  

 

My own procedure when using these types of hammers (and when I'm installing
them) is to first put them in a hammer caul (Renner sells one) and clamp the
caul to the work bench so that I can go through and needle the entire set
using the weight of my body leaning into the hammers which takes a lot of
stress off the elbow and arms.  With this method you can also see exactly
where you've been needling each adjacent hammer and keep the pattern fairly
uniform.  Renner hammers (depending on which ones) can require a fair amount
of deep needling this way before you need to bother trying to refine them in
the piano.  You will develop a feel for how much to do this way by squeezing
and by the feel of the needles in the felt.  After you are done the hammers
will have expanded somewhat in the shoulders and need to filed again to
recapture their shape.  The final passes and those closer to (and sometimes
across) the strike point I reserve for when the hammers are actually in the
piano and you can listen with each successive series of stitches.  

 

As far as regularly needling the shoulders for maintenance, I find that deep
needling need not and should not be done at each voicing.  It takes awhile
for the shoulders to pack in to the point where they need to be opened up
again.  Your ear will guide you but you can really only hear it on firmer
blows.  To test for resilience in the shoulder of the hammer requires that
you play the notes at mf and above-hard enough that you compress the felt
down to the area in question.  If the tone distorts and/or is swallowed to
quickly, you will need to deep needle the shoulders more.  

 

Techs who are weaned on the NY Steinway method of needling a lacquered
hammer only into the crown and apply those techniques to these types of
hammers are asking for trouble.   Eventually you will get a mushy strike
point with a rock hard supporting structure underneath.  When you try to
play a forte on a hammer treated that way you get a dull attack that
distorts somewhat painfully.  What you are shooting for is a firm but
resilient shoulder, very firm between the crown and the molding, a soft top
layer (1-2 mm depending on location in the scale) with a polished surface.
That will give you a nice dynamic range with a bit of shine to it.  

 

Of course, the rest of the piano (soundboard, strings, bridges, etc.) needs
to cooperate too.  

 

That's a start anyway.  

 

David Love
davidlovepianos at comcast.net
www.davidlovepianos.com 

-----Original Message-----
From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of David
Ilvedson
Sent: Tuesday, July 01, 2008 4:09 PM
To: pianotech at ptg.org; caut at ptg.org
Subject: [CAUT] Steve Brady's book...

 

List,

 

FYI...

 

In Steve's excellent book, he has interviews with technicians.   One fellow,
Ulrich Gerhartz, London Steinway, wrote about how he maintains the voicing
on his 13 Hamburg Ds...to paraphrase:   he starts with deep needling, low in
the shoulders.  All of the hammers...sometimes below the staple until he is
satisfied the shoulder felt has sufficient resiliency.  (I would like to
know how he determines that resiliency?...at Yamaha/Buena Park, they kept
saying I hadn't deep needled enough...;-]...the projection was quite there I
guess...) He then files to restore the shape and attack.  Maybe a few drops
of collodian. (wish I had access to that...?)   He finishes up with
polishing the hammers from 400 grit to maybe 1200 grit sandpaper.  He fits
hammers to strings with a hook rather than under the wippen/jack ala Yamaha.
I am interested in approaching our Hamburg D in this manner...I was
especially interested to read about the deep shoulder needling as a regular
part of the maintenance...apparently, with playing the shoulders get
compacted too...

 

David Ilvedson, RPT
Pacifica, CA 94044

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