On Nov 17, 2008, at 1:32 PM, Jon Page wrote: > Could it be that all that stiffener helped to shape the hammer > due to its lack of better construction by binding the layers? Are you assuming the hardness of the hammers was caused by additives (is that what you mean by stiffener)? I think it is just over pressing - too much pressure, too much heat. The fibers are squashed so close together there isn't any air space between them. Hence no springiness, and it is impossible to get needles in. When you do press or jab needles in, you are doing more tearing of fibers than you are easing them apart. I wonder if the pent up pressure in this kind of hammer isn't enough to make it explode when moisture is added, rather than the cause being excess needling tearing the felt. Or maybe a combination of the two. The best success I have with this kind of hammer is voice grip. I use channel lock pliers, adjusted to be parallel to the sides of the hammer. I do "bouncy" squeezes around the perimeter, then deeper in, shoulders only. Enough of this and I can get needles in. You can see the felt expanding. I like the channel locks because they give me a lot of leverage, hence control. (For uprights, this means action out of the piano to get access to the under shoulder). Regards, Fred Sturm University of New Mexico fssturm at unm.edu
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