I wonder if the impatience with which the hammer or felt makers go through the felting process doesn't have a lot to do with the difference. Instead of a denser interlocking felt fiber achieved by mechanical means, it is, perhaps, achieved now more by heating and pressing. That would make for a dense but less resilient hammer. I don't really know enough of the details of felt making but there are some interesting insights in the "Tone Building" book that Del Fandrich recently edited and released. David Love davidlovepianos at comcast.net www.davidlovepianos.com -----Original Message----- From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of John Delacour Sent: Sunday, October 07, 2007 10:44 AM To: Pianotech List Subject: Re: Walter 175 hammers David Love wrote: > Last I knew they were Ronsen Wurzens. You can tell by looking at the low > bass hammers and you should see some yellowish concentric circles moving in > toward the core... Ah! Now that's interesting. I had Abel make me a special set of hammers not long ago that had these very pale buff lines and guessed he had used Wurzen felt, though I haven't yet had a reply to my query -- probably because I didn't ask for Wurzen and also didn't get the undercover I very clearly specified. I haven't fitted them yet, so I have no idea what they sound like. The only time I've seen it before is on Broadwood grand hammers from about the turn of the century -- a very nice-looking hammer. I can't think that it will do any harm for hammers, but I've also had a sheet of treble damper felt supplied from Germany and here the layering of the felt is certainly not desirable : it is very difficult to cut smoothly and it can easily be torn apart along the line of the layers, which is useful on the rare occasions you want to do that, but but not for a whole sheet. I have reverted to French felt for the treble dampers, which is softer and better felted. As for the bass, I have just got some Yamaha strips and have a feeling, though they are more expensive, that I will start using these for all pianos, since the quality is far higher than what I get from Germany of France. Getting good felt has been a problem throughout my career. When I look at the quality of the stuff they used 140 years ago, sometimes I despair. JD
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