You can determine sufficient resilience in part by feel (especially when preneedling before you even install them you can squeeze the hammers at the shoulder and feel them start to give after a fair amount of needling) but mostly by the sound. Until the hammer gains some reliance it sounds like the attack gets swallowed very quickly. When there is sufficient resiliency, the tone will open up. I'm surprised to hear the he needles below the staple to gain resiliency. Needling down that low will actually release tension toward the crown and firm up the hammer somewhat. It is an effective remedy when you have slightly over needled a hammer. Andre O. has referred to this as "battery voicing". It does work. There is a limited amount of reserve down there though so it's best not to tap into it unless you have to. My own procedure when using these types of hammers (and when I'm installing them) is to first put them in a hammer caul (Renner sells one) and clamp the caul to the work bench so that I can go through and needle the entire set using the weight of my body leaning into the hammers which takes a lot of stress off the elbow and arms. With this method you can also see exactly where you've been needling each adjacent hammer and keep the pattern fairly uniform. Renner hammers (depending on which ones) can require a fair amount of deep needling this way before you need to bother trying to refine them in the piano. You will develop a feel for how much to do this way by squeezing and by the feel of the needles in the felt. After you are done the hammers will have expanded somewhat in the shoulders and need to filed again to recapture their shape. The final passes and those closer to (and sometimes across) the strike point I reserve for when the hammers are actually in the piano and you can listen with each successive series of stitches. As far as regularly needling the shoulders for maintenance, I find that deep needling need not and should not be done at each voicing. It takes awhile for the shoulders to pack in to the point where they need to be opened up again. Your ear will guide you but you can really only hear it on firmer blows. To test for resilience in the shoulder of the hammer requires that you play the notes at mf and above-hard enough that you compress the felt down to the area in question. If the tone distorts and/or is swallowed to quickly, you will need to deep needle the shoulders more. Techs who are weaned on the NY Steinway method of needling a lacquered hammer only into the crown and apply those techniques to these types of hammers are asking for trouble. Eventually you will get a mushy strike point with a rock hard supporting structure underneath. When you try to play a forte on a hammer treated that way you get a dull attack that distorts somewhat painfully. What you are shooting for is a firm but resilient shoulder, very firm between the crown and the molding, a soft top layer (1-2 mm depending on location in the scale) with a polished surface. That will give you a nice dynamic range with a bit of shine to it. Of course, the rest of the piano (soundboard, strings, bridges, etc.) needs to cooperate too. That's a start anyway. David Love davidlovepianos at comcast.net www.davidlovepianos.com -----Original Message----- From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of David Ilvedson Sent: Tuesday, July 01, 2008 4:09 PM To: pianotech at ptg.org; caut at ptg.org Subject: [CAUT] Steve Brady's book... List, FYI... In Steve's excellent book, he has interviews with technicians. One fellow, Ulrich Gerhartz, London Steinway, wrote about how he maintains the voicing on his 13 Hamburg Ds...to paraphrase: he starts with deep needling, low in the shoulders. All of the hammers...sometimes below the staple until he is satisfied the shoulder felt has sufficient resiliency. (I would like to know how he determines that resiliency?...at Yamaha/Buena Park, they kept saying I hadn't deep needled enough...;-]...the projection was quite there I guess...) He then files to restore the shape and attack. Maybe a few drops of collodian. (wish I had access to that...?) He finishes up with polishing the hammers from 400 grit to maybe 1200 grit sandpaper. He fits hammers to strings with a hook rather than under the wippen/jack ala Yamaha. I am interested in approaching our Hamburg D in this manner...I was especially interested to read about the deep shoulder needling as a regular part of the maintenance...apparently, with playing the shoulders get compacted too... David Ilvedson, RPT Pacifica, CA 94044 -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20080701/03ea8ece/attachment.html
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