At 09:17 PM 15/05/02 +0200, Richard wrote: >Hi John. I think before we get too far into such a discussion we need to >distinguish between a few things that this discussion necessarily touches on. > >First we need to clearly separate the concepts of "deterioration" and >"maturing" from one another, and that probably isn't as simple as it may at The concepts are quite distinct. For the purposes of this discussion, I've suggested that "maturing" could be a natural and scientifically described and tested process that wooden parts undergo called "creep and relaxation", which was explained and interpreted to some degree as well as referenced in the first message in this particular thread. Deterioration only enters into it here when "creep rupture" begins to occur and all other factors are ignored for now. >Secondly we need to look at to what degree our present knowledge base as to >what does happen to wood in instruments is complete. All we really need to know at this point is what happens to wood as an engineering material. In order to make it into a musical instrument you need to know how it reacts when you dry it, bend it, glue it, dowel it, finish it or ask it to support any kind of strain. The resource I used gives the figures for all those things along with those for the variables that make wood what it is. Most of the things that happen in a musical instrument depends on how well you know those things. >Does it fully explain all >the observations made by various individuals, and for that matter are those >observations made under strict enough rules to be useful for scientific study. The Wood Handbook from which I drew my reference is a publication of the United States Department of Agriculture Forest Products Laboratory. If I may quote from it: "This handbook was prepared by the Forest Products Laboratory (FPL), a unit of the research organization of the Forest Service, U.S. Department of Agriculture. The Laboratory, established in 1910, is maintained at Madison, Wisconsin, in cooperation with the University of Wisconsin. It was the first institution in the world to conduct general research on wood and its utilization. The accumulation of information that has resulted from its engineering and allied investigations of wood and wood products over nine decades along with knowledge of everyday construction practices and problems is the chief basis for this handbook." I would hope the properties of wood that it describes are scientific and tested since they say they've been doing it for over 90 years. >This is where I observe a distinct lack of science data to base our opinions >on. We are still talking about "wood as an engineering material" on the basis of a handbook that was painstakingly put together for the use of engineers so they can have reliable data upon which they can make decisions. Is it "all fully explained"? Is anything? >While all the time keeping separate the basic issues of what constitutes >damage, what constitutes maturity, and what is simply change in physical >quantities. They aren't really separate here. Maturity is successfully surviving the changes introduced by creep (among other things) in the various wooden parts over time. Long-term survival is dependent on creep rupture not becoming a big enough problem as to make failure of the part a probability. The phenomenon appears to say that when piano parts are made into a piano it takes a number of years for them to want to stay that way. My hypothesis is that a piano "matures" when creep becomes much less of a factor then it was before the wood was stressed. Conversely, pianos begin to "fail" when creep rupture occurs. >Now nowhere in any of this is there the slightest hint of magic or >mysticism or >the like. The purpose of this discussion was to try to remove those factors as well as personal opinion and bring it into the realm of natural science. >This is a stance with feet planted firmly in opposite plane. The >admission that we don't have enough data to make more then at best a hesitant >claim, or a tentative hypothesis. While I admire your skeptic's stance on this we have a great deal of scientific data available to us on the properties of wood as an engineering material. It does certain things whether it's in a piano, a bridge or a book case. The question is whether one of the things it does is responsible for a phenomenon that some acknowledge, some disparage and others cherish. >Just my view from the far North :) As was mine from a mere 51 degrees N. John John Musselwhite, RPT - Calgary, Alberta Canada http://www.musselwhite.com http://canadianpianopage.com/calgary Pianotech IRC chats Tuesday and Thursday nights and Sunday Mornings http://www.bigfoot.com/~kmvander/ircpiano.html
This PTG archive page provided courtesy of Moy Piano Service, LLC