This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment HAMMERMAKER'S CORNER 7. ARI ISAAC. At this point my luck, or was it my persistance began to change and to = produce better results. I had to give up on ordering felt from = Whitehead, Royal George, because their quality went way down while their = arrogance remained as British as ever. I called a company called Bacon in the U.S. and got. nowhere. The first = response I got when I told them about my ideas for the sheets of hammer = felt I wanted was "We'd need an order of 1000 sheets to implement the specifications you = want". So much for that. I had to learn the tough lesson not to give up without = more than one try. I had laid out my ideas to them and left it at that. = One day I get a call and it is Mr. S. their felt expert, with whom, = previously, I hadn't been able to connect, he was asking me what they = could do for me, I couldn' believe my good fortune. Here was a man who = knew felt and who understood what I was saying to the small detail. The = felt sheets I began to receive were beautiful. First, they produced a = musical tone right out of the box. Next, their tone remained stable and, = this I found out later, these hammers had a longer life span than = anything else out there. Mr. S. told me that in the 1920s wool for piano hammer felt was picked = according to criteria no longer used. One of these criteria was the = region the wool originated from. Another was the quality of the pasture = in the region for a given year. Another, this one important, is = bleeching the felt. I told him I never would used bleeched felt as the = bleeching removes even more of the wool's natural resilience. My idea of graduating the felt density from bass to treble turned out to = have an added advantage, one I could not have known about. As the wool = grade fiber becomes thinner - a longer fiber is needed to felt = successfully. The longer the fiber - the more efficient the spring in = the hammer. Now it was time, I felt, no pun, to determine the precise rate of = density graduation in the bass to treble axis of the sheets I would use = to make Isaac Cadenza hammers. There are two measurements to be taken: durometer hardness and creep. = The first, durometer hardness, is the measure of surface hardness where = glass =3D 100. Many hammer makers try for 90/95 durometer in the extreme = treble of their hammers. Hardness, as a measurement is useful but a poor = indicator of tonal quality.=20 A durometer consists of a blunt pin (about .045" diameter) attached to a = gauge and pushed by a spring. This pin protrudes from the bottom of a = weighted box housing the gauge. The durometer is set on the face of the = sheet of felt and for the hardness reading the surface resistance is = measured. Creep measures the time it takes for the fibers adjacent to = the point of the spring loaded pin to allow the pin to penetrate the = surface (or not). Measuring a sheet of glass will allow no penetration. = The pointer measuring creep will not move. When measuring, say, soft = foam, the penetration will be very quick and deep (pin sticks out not = much more than 1/16"). The creep measure, the number pointed to on the = gauge, will be low indicating a very low resistance to the pin's = penetration by the surrounding material. When measuring the creep on = hammer felt used for Isaac Cadenza hammers the creep pointer will = indicate a number that is high and the pointer will move very slowly = indicating a resistance of the area immediately surrounding the = protruding pin. Measuring hammer felt the creep is a far better = indicator of felt spring, resilience, than durometer hardness. ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/caut.php/attachments/90/96/0a/b5/attachment.htm ---------------------- multipart/alternative attachment--
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