>The question is: why is it better to replace the whole soundboard with >new wood rather than carefully withdraw the old one, unglue the ribs and >bridges and next re-dry the sb. and reglue everything into place? * Always replace the panel and ribs. The old wood has accumulated a lot of years of compression set that has damaged the cellular structure too badly to allow it's reuse. Wood does not gain 'resonance' with age, it only loses strength and elasticity and becomes less mechanically responsive to energy transfer from the strings. Resonance is not really a factor in soundboard woods anyway, or shouldn't be. The soundboard is a transducer, whose job it is to efficiently convert the strings' vibrations into sound without adding or subtracting anything. That's not entirely possible due to internal friction in the assembly, non rigid string termination, energy absorbtion by the rim, etc. Soundboard response at any particular point in the scale is determined by the rib scale, panel thickness, grain angle, bridge placement and stiffness, downbearing, assembly mass, crown, and a little statistical probability drift (dumb luck). The resonant properties of the panel have little to do with anything. A much more important factor is the elastic recovery and load bearing properties of new wood. Replace everything, and machine crown the ribs, whether or not the originals were, so the panel isn't doing all the work of maintaining the crown. >Many customers ask me what I have left of the "Steinway" if I have >replaced everything. (I had this question also before when I simply >replaced a set of hammers!) I must admit now that this question makes >more sense to me, since if I replace completely the sb. of a Steiway it >is no longer a Steinway, although it was clearly needing it. >I use to answer that: what's left of a 80 years old Steinway precisely >after 80 years off the factory?... * If they want an original Steinway, why are you rebuilding it at all? Never mind that it isn't playable, it's sacred originality is still intact as long as no one tries to fix it. If they want a playable instrument, parts are going to have to be replaced. I don't see the recipients of hip replacement surgery crying about the loss of the original joint that made it impossible for them to walk. If they want a good job, it will require upgrading parts by replacement with higher quality components without regard to compromising performance to maintain an illusionary mystique. I'll chose column 'A' any time and replace parts if it will improve function. > >Well, what I would like to know is if there is any known structural >changes on wood during time, I mean if there are significant differences >between new vs. old wood in, for instance, capacity of moisture holding >or absorption, vibrational behavior, strength, irreversible deformities, >etc. Where can I find such information? * 'The Encyclopedia of Wood' Sterling Publishing Co. A 1989 reprint of the 1987 revised edition of 'Wood Handbook: Wood as an Engineering Material', from the U.S.Government Printing Office. ABSOLUTELY REQUIRED reading for rebuilders. > >By now, I do prefer to recrown the old sounboard (although ungluing it >without damage is like a nightmare) but I wish to know your opinions. > >Thank You > >Josep Puig * I don't recommend it. Regards, Ron
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