Hey...how'd I get my name in the subject line now....? Joe wrote: >You can get leather that is acceptable to use on hammers. Fortepiano builders describe the situation as "using the least unsuitable product". >Your statement: >"...you can't get the proper hammer leather now, and what you can get >probably will start flapping about after a bit of playing....", is >essentially incorrect. Well most experienced fortepiano builders (and fortepianists who do their own work) will tell you this is perhaps the single biggest problem in working with modern materials. >I have been doing this procedure for many years and I >have yet to have the leather "flapping about after a bit of playing". It >takes time and skill to do it right, but not a high level of skill. I think the meaning of my "flapping about" here is being misinterpreted - I don't mean that literally. I mean sufficiently loose to have an undesirable acoustic effect, which doesn't take very much at all, and certainly not enuf to be visible. It is something that develops with playing, often within days. Some leathers are better than others (hence it is possible to find the least unsuitable material) but all modern leathers will eventually stretch, because of the way they are made. The slightest degree of looseness will translate to poor tone, a problem that happens on fortepianos - I'm talking about hammers that are built up with multiple layers of leather. I don't doubt that an acceptable repair covering to a modern hammer can be made with carefully selected modern leathers, but I would question why is should be necessary to apologize to the customer and describe it as a temporary fix? (Possibly because only specific hammers are treated this way and stand out from their neighbours). Felt hammers, covered with the proper kind of hammer leather, should be perfectly good tonally and extremely durable - exactly as described by Keutzig. There's no reason not to use hammers of this kind on modern pianos - except for the lack of suitable leather..... >As for the proper leather, I would say contact the gentleman who >advertises in the >back of the journal, (I can't recall his name/company at the moment...it's >late). He can most certainly provide you with the proper leather. If not >then try Fletcher & Newman in England or Renner/Germany. As I said last time, hammer covering leather is, and always was, a highly specialized, targetted product, even in the 19th century. It was made in small quantities, following a lengthy, specialized process (combination tanning - oil and vegetable, followed by mechanical treatment), to achieve the required properties: high compressive elasticity, rapid mechanical memory, high shear strength, high Young's modulus, resilient, and soft. (These properties tend to be mutually incompatible under normal leather making processes.). Modern leather is nothing like the old hammer leather because modern leather is not made according to the old recipes. Obviously if you want to use leather you have to find the closest modern stuff, and that is what fortepiano builders do too. But it is not the same as the proper leather as it was when piano builders still used it on hammers. I have a current project on the go to replicate the old process - if it turns out well I would provide some samples if anyone is interested. Stephen Stephen Birkett Fortepianos Authentic Reproductions of 18th and 19th Century Pianos 464 Winchester Drive Waterloo, Ontario Canada N2T 1K5 tel: 519-885-2228 mailto: sbirkett@real.uwaterloo.ca http://real.uwaterloo.ca/~sbirkett
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