David, I DO like using fabric softener on old compressed hammers especially on old American pianos. . I use the ultra Downy that is white in color, so there is no color change. I use about a 7 to 1 ratio in ACETONE. I don't like using rubbing alcohol or any alcohol containing water as it can soften the glue in the hammer. Acetone will not do that. In my experience the fabric softener in acetone will bring must hammers back to about their ORIGINAL condition. That is, if they are hard pressed hammers like in Asian pianos, the effect is not dramatic. The same with newer Baldwins. With Asian hammers like the rock hard ones you describe, I put a number 80 drill in my Dremel tool and drill the hammer through the side, from side to side- not down into the face as one would needle. This is very forgiving. I drill three holes first at 1/8 inch intervals starting just under the contact point then deeper and deeper down to the core felt. I test the effect and in almost every case put two more holes on either side of that line of holes at about 1/8 intervals. Sometimes I use the 5 of hearts (playing cards) pattern. The pattern is not that critical. I use only about 3 holes in the treble hammers. The nice thing about this method is that it does not disturb the the contact face of the hammer nor does it swell or compress the contact surface as with alcohol or pliers. Obviously, if filing and shaping is needed. I do that first. I usually finish by brushing the contact surface with a brass suede brush to "sugar coat" it. this can all be done in about 30 minutes. Doug Gregg Classic Piano Doc
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