This message has been cross posted to the following Discussions: Hammers and Voicing .
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There has been lots of discussion over the years about the differences between hot- and cold-pressed hammers. Some manufacturers, including Renner and Abel, claim to do "warm"-pressing, but it has been difficult to nail down what that means. This summer, though, when I asked Norbert Abel about pressing temperature, he responded "40º" without hesitation. He said it was just to make the felt a little more flexible.
40ºC = 104ºF, or a hot summer day in Albuquerque (a mild one in Phoenix). I can't see that that degree of heat would have any deleterious effect on the wool fibers, or that in itself it would make any significant difference from "cold" pressing (which would be at the temperature of the room where the work was being done: does that mean 60º? 80º? Does it depend on the time of year?)
This is borne out in my experience in voicing new Abel versus Ronsen Weickert special hammers (I put on a couple sets of each this summer). Needling felt about the same, and the results sounded essentially the same. I essentially use the procedure recommended by Renner: deep needles pressed into shoulders in a regular pattern, with the aim of increasing the tonal gradient. That's what I did, and the tonal gradient did, indeed, increase, become more gradual and higher at the top end, on both types of hammers.
I suspect that in past years both Renner and Abel used more heat than that, but I don't know how to find out. The hammers seemed far denser and harder to get needles into, in any case, and it took a lot more insertions to get acceptable results.
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Fred Sturm
University of New Mexico
http://fredsturm.net "When I smell a flower, I don't think about how it was cultivated. I like to listen to music the same way." -Federico Mompou
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