>I'd tend to think that we can gain a little sustain with good >terminations, and precise bearing, but the kind of gain we obtain with >a temporary fix, as DB on a yet flat board, lend to an unpleasing >tone, and probably not lasting long repair. Or we can not kill what little is left with inappropriate bearing and poor terminations, depending on how you look at it. But yes, when the board is flat and dead, the tricks with bearing and termination aren't repairs. >Yes, next step is .... buy a Clavinova Careful. >BTW what rule of thumb applies for the drilling (reaming in my case) >of the bridge pins , I'd consider 1/10 mm (a bit more than 1/32) drill >less to be a maximum for these pins ? I have all sizes drill by >tenths. About 0.004", so I'd say that was just about right. >Considering the use of C.A., the product is known to not really resist >to shocks, then it may turn into powder may be, or is it only that it >break while remaining it's shape (loose bond) ? Here's the deal with CA in bridges. Since boats are more piano-like than violins, I'll use a boat analogy. Glass isn't known for it's shock resistance. Epoxy isn't either. Epoxy soaked glass cloth over a thin plywood boat hull makes the whole assembly a whole lot tougher and more impact resistant than any of the component parts separately. CA by itself has little impact resistance, and wood is fairly easily compressible by either impact or pressure. CA soaked wood is a plastic impregnated fiber, just as CA soaked into wood is a fiber reinforced plastic. The sum of the two is less easily compressible and more impact resistant than either separately. >I can have minimal bearing (but some) without forcing the board flat. >Beside, I see no real difference between flat and almost flat (from >the tone point of view) advantage is that the tuning is not affected >by humidity swings ;>) >Could it be that there is a point (flat board) where the board is more >prone to collapse, even under a minimal bearing ? A flat board has already collapsed. A board that has minimal bearing and very little to no crown is on it's last legs, or maybe leg. That's with crown and bearing measured in all reachable areas of the board, particularly in the killer octave where boards generally go flat first. >I guess I will try a metal belly brace on this one, that cannot be >bad. Like chicken soup for a cold. Might not help, but couldn't hurt. > > Bearing should be set with crown and the stiffness of the > > board in mind. If the board is dead, it's dead. > >The board is responsive , but in the ZZZZZone , may be some >amplification ? Say again. I don't understand what you mean. >It is an opportunity from a colleague of mine that will leave the >country, strong large press classical model, very useful for more than >bar gluing. It can be modified I guess to accommodate pneumatic setup. No no no, the pneumatic press is an entirely different system. from a go bar deck. Ron N
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