----- 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
This PTG archive page provided courtesy of Moy Piano Service, LLC