help a beginner measure mc in wood with confidence

[erwinspiano at aol.com]

Jim
? In my climate it is difficult to find a day of extreme dry or damp. Never the less 30 to 50 % rh is a reasonable range in which I don't' worry about bearing set up. I can go back later & check my target bearing & it's usually spot on but I spend a lot of time & care?making sure it is. Very fussy bout bearing set up. It's gas in the tone tank. I? always check it after it's pitched up. It's my mental insurance policy
???I shoot for Mc of 6 % as a general rule of thumb. The desert panels get dried ?a bit drier & the ocean a bit higher 6.5%. Yes by all means prove it to thyself. My first experience of this took me a while to believe it.? C.C. boards are way more reactive.
?? SO Jim, just provide your shop with an mc you feel removes the variables just to say you did when thinking about it later.
? Just remember we all do things just a little bit differently than the next guy.
? Regards
? Dale?





ROn and Dale,

I understand and am on board(no pun intended) regarding relative crown stability 

of pianos with RC&S boards..

Let me go back and try to be more clear on what my questions were. Here are 2 
questions, and I'll reference my original statement/question.

1-The point of  my copy here:

"I'm doing RC&S boards...5% is not in my repertoire. For downbearing 
measurement, 
I'm shooting for around 7-7.5%mc.  Both yourself and Ron seem to be saying the 
crown of an RC&S board is not variable at different mc's.  I'm chicken and will 
have to prove that to myself before I trust it."
 
was one of procedure.  

So my question reflects this procedural issue; 

IE, Is the stability of the RC&S crown such that (in an RH variable shop) mc of 
the board, when taking downbearing measurements, is not important and verifying 
mc with some mc reference is unnecessary?

2-The point of this copy:

"But one other mc frustration I have is that after all is said and done, the 
board ribbed, in, downbearing done, strings up to pitch, I want to come back and 

observe exactly what I have achieved for future reference. IE, have the "as 
built" deflections hit the target crown deflections of the design. Not knowing 
what the mc of the board at this point is, to me, adding a variable which I want 

would really like to exclude."

was similar to above.  

IE. are you saying that measurements of crown,  to verify (for 
future use), what your as-built loaded crown deflection was as compared to your 
designed loaded crown deflection, can be taken without  regard to the mc of the 
board at that 
point, because of the stability of the RC&S crown.

Hope my question is clear-er-er
--
Jim Ialeggio 
www.grandpianosolutions.com
Shirley, MA (978) 425-9026

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