On Jul 28, 2010, at 8:55 PM, Israel Stein wrote: > I thoroughly researched this in the PTG e-mail list archives and > have gotten some private correspondence from someone with extensive > experience using collodion , and both sources specify collodion > U.S.P - which is flexible - or "flexible collodion". My private > source concurs that rigid collodion is not a good choice - it would > essentially do the same thing as lacquer. > > My theory is that the fundamental difference between the NY Steinway > hammer (which is not made to be springy) and the European style > "springy" hammer is what makes lacquer - or any other stiffener - > appropriate for voicing them, but not appropriate for the European > style hammers. You don't want to make the springy European style > hammer fibers completely stiff, because this spring-like quality > makes a major contribution to the tone. Filling them with a rigid > hardener - like lacquer or rigid collodion - makes them less > springy. I think, rather, that the flexible collodion binds the > fibers together while maintaining this flexibility. Just my theory > to explain the empirical observations of my sources. Israel, Thanks for the additional thoughts and research. A few more thoughts of my own: One hardening substance that seems like it would be considered "flexible" is keytop in acetone. "Keytop" is an inexact term, as different keytops are made from different plastics, but I think we can say they all share having more "flexibility" than lacquer. Now the standard use of this, as defined by Steinway basement guys (Ron Coners and Eric Schandall being major sources of info) is a light solution applied right on the crown. What does it do? Glassy is the adjective that comes to mind, before it has been needled a bit or scuff sanded. IOW, it doesn't seem to have the sound we would expect from a flexible substance. Of course, there is also the wild card of the acetone re-amalgamating lacquer that had been broken by needles - and applying pure acetone to lacquered hammers gives similar results - so it is not clear what the pure sound of keytop is unless you apply it to undoped felt. My experience with that (top few notes of Abels or the like) is that it does sound relatively glassy - though I don't seem to need to take it back down as much. I can usually apply it and leave it, maybe apply a bit more. With lacquer, as a relatively brittle substance, my mental model of voicing a lacquered hammer has the coating on fibers shattering as a needle is inserted - the fibers impacted by the needle directly, and some of the fibers pressed against by those displaced by the needle. Fibers not impacted by the needle remain stiff. This assumes a fairly weak application, where it is mostly coating the fibers, not filling in the space, not bonding the fibers together into a composite construction. With keytop, or another more flexible material, I picture the coating of the fibers being less likely to break, more likely to simply move with the fiber when the needle is inserted. I also imagine more of a "bonding" at points where fibers cross, the material holding those "joints" together more securely. I haven't done too much voicing of hammers impregnated with keytop, but I have done some (following a couple idiots), and found that the felt was "stickier" to get the needles in than with lacquer. With lacquer, I feel a sort of crunchiness and hear a crispy sound as the needles go in (with a moderate amount of lacquer, that is). With keytop, I feel and hear none of that, and it seems like I am punching a hole in somewhat gummy substance. Of course, it might well be different with less keytop material in the felt - I was following a definite over dosing, and ended up flushing the hammers. Anyway, those are some thoughts along these lines, which have led me not to be that interested in the idea of trying flexible hardeners myself - though delighted to learn about other people's experiences. Regards, Fred Sturm fssturm at unm.edu http://www.youtube.com/fredsturm
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