[pianotech] Glue for hammers - question

Ed Sutton ed440 at mindspring.com
Mon Jun 8 04:06:07 MDT 2009


David-

A steel hammer would strike an even firmer blow. How would it sound?
Would a gold hammer sound "golden?"
Does a wool hammer sound "wooly?"

You could find out: hang a hammer with CA glue, which is very hard, and hang 
its neighbor with PVC-E, which is very flexible. Do some blindfold tests, 
asking people to describe the differences in sound.

My guess is that the flexing of the hammer shank, and the intended 
flexibility of the wool hammer, exceed by far any difference in flexibility 
in the glue joint. And please remember that the jack is not driving the 
hammer at the moment it contacts the string, the hammer is moving because of 
its own inertia. It is not the same as a hammer driving a nail, it is more 
like a mallet striking a gong.

I respect very much your concern for getting every detail as correct as 
possible, but feel we need to examine carefully every idea of correctness we 
can test. Poetic understanding can help us attain higher levels of 
perception, but it can also lead us into wonderful blind alleys. We need to 
be aware of seductive words. I knew someone who insisted on putting the 
cream into his coffee cup first "so that the coffee would warm up the 
cream."

Ed


----- Original Message ----- 
From: "David Ilvedson" <ilvey at sbcglobal.net>
To: <pianotech at ptg.org>
Sent: Monday, June 08, 2009 12:34 AM
Subject: Re: [pianotech] Glue for hammers - question


> It's all those little things that make the difference, imho.   To me it 
> makes sense that hammer would hit the string with a firmer strike if the 
> glue joint did not flex an iota...
>
> David Ilvedson, RPT
> Pacifica, CA  94044
>
> ----- Original message ----------------------------------------
> From: "Ron Nossaman" <rnossaman at cox.net>
> To: ed440 at mindspring.com; pianotech at ptg.org
> Received: 6/7/2009 7:19:06 PM
> Subject: Re: [pianotech] Glue for hammers - question
>
>
>>Ed Sutton wrote:
>>> I am curious what the arguments or evidence may be for the tonal
>>> superiority of a rock solid hammer to shank joint.
>>>
>>> A rattling joint is not good, but what is lost if there is a small
>>> degree of flexibility in the glue?
>>>
>>> The hammer felt itself is definitely flexible by design, and not rock 
>>> hard.
>>>
>>> The hammer is not being driven when it reaches the string, it is moving
>>> by its own inertia.
>>>
>>> It is generally considered desirable that the hammer stay in contact
>>> with the string a period of time, and not rebound instantly.
>>>
>>> Eugene Thorndahl, the former glue chemist at Peter Cooper, suggested to
>>> me that a small amount of glycerine added to hide glue would give it a
>>> little more flexibility, and produce a more dependable hammer joint, but
>>> he was addressing the strength of the joint under stress, not acoustic
>>> issues.
>>>
>>> Ed Sutton
>
>>And don't forget the action bedding, and the flange pinning,
>>and the backcheck height (2mm below the tail at drop), and the
>>front rail punchings, and the coupling of the casters to the
>>floor, and the room acoustics, and the front leading in the
>>keys (for inertia control), and the hammer needling and
>>lacquer application techniques and locations, and the duplex
>>scale tuning, and, of course, the A-4 pitch and temperament
>>choice. Why, with all this sterling ammunition, are these
>>things still being endlessly debated as if they were real? All
>>evidence considered, it doesn't seem to much matter, since
>>it's not apparently possible to make the right set of choices
>>in *any* specific situation.
>
>>If all this nonsense still hasn't been hashed out by now in
>>the real world of day to day piano service, what's the point?
>>Ron N
>
> 



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