Results are In! Re: moisture in wool or wood.

[Delwin D Fandrich]

----- Original Message -----
From: "Diane Hofstetter" <dianepianotuner@hotmail.com>
To: <pianotech@ptg.org>
Sent: January 14, 2001 12:22 AM
Subject: Re: Results are In! Re: moisture in wool or wood.


> Nothing seemed to be conclusive, but when I read from Del Fandrich's post
I
> became quite excited, the hammers on my customers piano are from Superior
> Imports, installed about ten years ago. Del said:
>
> >>replaced them. Since we
> figured there was nothing to lose, we tried saturating them with alcohol
and
> water.
>
> (By the way, during this time touch weight went from approximately 62 to
64
> grams downweight down to 52 to 54 grams downweight with the original key
> leading -- three towards the end of the key through the bass.)
>
> Now that's a significant reduction in touch weight!  I have a sample
hammer
> from Superior Imports shanked up to put on our Kawai GS50 for an
experiment
> we did in comparing different brands of hammers on one piano many years
ago,
> maybe I'll reinstall it and try to flush out some of the hardner, then I
can
> measure touch weight and listen to tone.  Thanks for the idea, Del!
------------------------------------------------------------------

Diane,

The weight reduction came from the rather large amount of felt I sanded off
of these hammers.

Each time I soaked them the water acting on the felt caused them to swell
up. After they dried some of this swelling remained and I sanded them back
down to their original size. I don't remember the exact details right now,
but after the first soaking the bass hammers measured something like 3 or 4
mm wider across the shoulders. I sanded them back to their original
dimension and soaked them again. By this time I was using about 50% alcohol
and about 50% water. After the second soaking they ended up about another 2
mm wider across the shoulders once they had dried out and I sanded them back
down again. And soaked them again. This time they only swelled about 1 mm
across the shoulders and, again, once they had dried out I sanded them back
once again. They were also swelling at the top of the hammer -- the strike
point -- all this time though not as much. I also took this back down to the
original o/a hammer length. After all of the soaking, drying and sanding the
hammers ended up back at approximately their original o/a size and shape
although they now have a lot less felt on them. Especially through the upper
third of the scale where I ended up removing the staples and taking off
quite a bit of low shoulder felt. These things actually look like piano
hammers now.

So...the weight reduction did not come from washing out any kind of chemical
hardener. I doubt there was any in there. It came from all the felt I sanded
off.

Regards,

Del