---------------------- multipart/alternative attachment On 7-mei-05, at 11:32, David C. Stanwood wrote: > Hi All, > > I'm always very interested when the discussion turns towards felt. > Being married to a feltmaker has given me a deeper insight into the > science and nature of wool felts. I've devoted years to the studying > felt making felt and experimenting with felt. Many of you may > remember many of the PTG classes I used to give on the science of felt > and how I promoted in the 1980's a return to cold pressed hammers and > the use of finer quality fiber in piano hammers. I'm excited to see > a renewed interest in improving fiber quality and production methods > for piano hammers. I love the cold pressed Wurzen felt hammers made > by Ronson. However....... > > I'm here in Holland at the shop of Frans Pietjouw and I'm looking very > skeptically at one of these conical punchings. I'm struck by the fact > that they are made from presssed felt and not woven felt. Woven felt > is the technical choice for high impact areas because it greatly > reduces compaction of the felt over time. That is why it is ALWAYS > used for back rail cloth, balance rail, and for front rail punchings. dear Mr. Stanwood, I am of quite a different opinion. The conical punching we are very happy to promote, is NOT made of pressed felt, but purely 'felted' felt made in the Wurzen factory. Since you have, as you say, "deeper insight into the science and nature of wool felts", you may know that the process of interlocking the wool fibers is the heart of the matter of making felt. Most felt makers are not yet able to produce felt with a maximum interlocking, and in order to yet get the same weight and density, they have to press their felts - as well - to get the desired compactness. I know for a fact that the Wurzen felt factory is about the only place where felt is made with maximum interlocking without pressing the felt. That only makes all the difference in sound, voicing, and durability, and that is why both piano technicians and pianists should be very happy that Mr J. Brand, the director of the Wurzen factory, has given so much of his time and ingenuity to bring this gorgeous felt again onto the hammer making market and the piano industry in general. The fact that this felt is not pressed, but on the contrary has a high and natural elasticity, due to the superior Wurzen felting process, causes it to react in quite a different way, and in a way many technicians have not yet experienced. That is also why you like so much the AA quality Wurzen felt that Ray Negron of Ronsen hammers uses on his hammers, which I btw introduced to Mr. Negron, and for that matter into the USA). (I have learned that this kind of felt is in the US called "pressed felt", but that phrase is incorrect and probably points to the way 'other' felt makers operate) > I would never recommend the use of this type of felt on the front rail > because it is a high impact area. Using pressed felt in this area is > technically the wrong choice. Over time, pressed felt will compact > more quickly than woven felt causing dimensional changes which will > effect regulation and it will get harder faster than woven felt when > exposed to repeated high impact. Here too I am of a totally different opinion. The new Wurzen felt front punching has been tested extensively in many kinds of piano's by both piano technicians and pianists. The high quality and especially the natural elasticity of the felt makes it a most perfect shock absorber, better than the best woven ones because they are slightly more compact, and that becomes immediately very clear when we regulate for instance a grand action. Regulation becomes a much more precise issue with these punchings, and much more fun too because the result speaks for itself. Furthermore, several technicians here and in the US have tested the elasticity of this punchings, and one of them is Dr Stephen Birkett, Associate Professor Department of Systems Design Engineering, University of Waterloo, Waterloo ON Canada N2L 3G1 who wrote to this PTG list saying : quote For now, high speed videos (forte blow) show that there is an obvious mechanism whereby the properties of the punching can influence the hammer during escapement, and consequently the touch and tone. [It's not easy to set up these videos with a single high speed camera oberving events that are not in close proximity] I've also looked at the dynamic behaviour of the punchings themselves using macro high speed imaging. Green woven felt punchings show a definite sloppiness and tendency to shear on impact, and a much less clean deceleration, with distinct wobble of the key off the vertical as the punching is compressed. These observations are not seen with the Wurzen punching, presumably because the superior interlocking of fibres prevents the shearing observed with the woven material. unquote About the behavior of inferior woven front punchings, we knew already years ago, long before we brought our punching on the market. The fact that Mr. Birkett has tested this new punching and other punchings in a more scientific way and acknowledges its superior qualities, is so much the better for those who still doubt the qualities of this beautiful Wurzen felt. I am furthermore of the opinion that it is much better, in general, to replace front rail punchings from time to time, because, of course, every felt or woven punching will eventually flatten out or get hardened. It is fortunately a relatively inexpensive piano part and a 'punching exchange' after some years always brings about a remarkable improvement in touch and tone. > I have also just tried out these punchings in a very beautiful vintage > Steinway A which is in the shop down stairs and I notice no difference > whatsoever in sound when changing from original new Steinway punchings > to the conical punchings. I know that a sample of one means nothing > statistically and this is only one example but there it is. In the last year, there were only 2 remarks on the list from technicians in the USA who were not able not distinguish any difference. For those (and in general) I have written the following : quote if any of you can not tell the difference, it maybe due to : a badly regulated instrument - the malfunctioning action makes it impossible to distinguish any difference. a badly voiced instrument - the too soft or too hard hammers make it impossible to distinguish any difference. a front punching which is just, or about, as firm as the Wurzen replacement. you perhaps lost your finest sense of touch and maybe also your finest sense of hearing. a sad combination of the above unquote In any case, we (Grand Piano and Piano Forte Supply) are not selling this punching because we wanted so badly to sell yet another front rail punching. That would be ridiculous with all the already existing punchings, good and bad. Of course we launched it, because we immediately recognized a surprising improvement in touch and tone, and of course we are not the only ones. Already many technicians on the list - and not on the list, or privately, have stated very positive reactions and also many pianists have made it more than clear by begging us to instantly install the new punchings after we gave them an objective demonstration. All this shows clearly that this is absolutely not a commercial hoax or yet another story of "the emperors cloths". I am a voicing technician who was fortunate to learn about the 'new' Wurzen felt at the re-introduction 15 years ago. From that moment on, I instantly recognized its value and it was me who wrote articles about it for piano magazines it and who wrote endless emails to the list. I am sorry for you that you are not able yet to recognize the value of the new punchings. Maybe you should give it another try? on other instruments? elsewhere? A. Oorebeek ---------------------- multipart/alternative attachment A non-text attachment was scrubbed... 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