Do you dry the ribs, along with the board, prior to gluing ?

[Erwinspiano at aol.com]

Hey  RIc   --Greg
   Been out of town & missed a lot of this. RIc you  make a good case here 
with room for reasonableness.

Hi again  Greg...
Certainly as a CC board an old panel which has been weakened  
due to compression set will be difficult to make work as a CC board.   At 
least more difficult then a new panel.
  You bet

The degree with which the panel 
has compression strength left is the  determinant here.  Feasibly one 
could de-rib such a panel, dry it out  and use it again in some kind of 
compression reliant assembly with  success.
  But I probably wouldn't advise it or sell it with a  warranty to a client. 
It would depend on the integrity of the panel & the  desired outcome expected 
by the client & rebuilder. For some folks the wood  is sacred & for others the 
wood is a crap shoot & a risk not worth  taking.

Using it  in an RC & S assembly on the other hand should be quite alright 
as Del  stated some years back.  I believe there is some truth to what 
Thump  posted about old wood... and as a result I would think such an 
assembly  would sound a bit different then an assembly using a brand new  
board.  But perhaps any difference is marginal after  all.
     Using a panel such as this would be  only wise if the panel was by in 
large Rib crowned & supported &  dried to no more than say 6%



I am kind of skeptical to using phrases like "cellular  destruction" 
myself...  not because there is anything inherently  untruthfully about 
the phrase... but because it conveys a sense of the  wood being rendered 
totally useless as a soundboard... which clearly is  not the case.
 Some panels which have survived really well perhaps  not but, When doing 
restorative work Udo was removing the badly damaged &  cellularly destroyed wood 
& then machining  a new joint & then  gluing the panel back together. Kind a 
like removing dry rot.  I'd do the  same protocol if called upon
  
  Ric...  A split panel caused by compression  ridging due to climate & 
bearing pressure is what it is because  it has at least in some locations exceeded 
the elastic limit of the wood.   Now come on Ric. 

I also  believe the whole compression set argumentation is well 
overstated. Not  meaning to deny it is a significant factor in the life 
of a soundboard ...  but I do find that there are very many old pianos 
that have very nice  sound by any standards left in them.
  No question. But many more do not.
  Pure 
statistics leads me away from accepting compression  reliant panels as 
having a built in self destruct  mechanism. 

Well  they due when dried to extreme 

Treat  them well... give them 
a reasonably nice climate... and they will hold up  nicely for a very 
long time indeed.
  No Argument here
I know there are many on piano tech that disagree. 
  Yes & at the end of the day it's up to each one to  make there best choice 
of methods based on what they know works, feel  comfortable with or understand 
that theie design is pushing the tonal for good  reason & thier clients are 
good with that.
 I also note that the 
vast majority of pianos made today rely on  significant degrees of 
compression in there soundboards. These companies,  at least many of them 
I believe... are well aware of all the issues we  discuss and their 
significance.
  Maybe not but thye make this their choice any way &  the results are as we 
see in the field.  Some good , some great &  some.........
  I haven't read all these myriad of post but  one essential element is being 
grossly over looked & that is the Rebuilders  interest in designing  a sound 
board with a varity of tonal envelopes such  a what was heard in Rochester. 
    Cheers back at Ya
     Dale



Cheers
RicB

 



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