laminated ribs

[Erwinspiano@aol.com]

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Steve
  Sorry for the late reply.  I've been preparing  pianos for display at the 
Calif. State Convention.   I truly  appreciate your frank and honest subjective 
evaluation of the subject.  I  have not had the same experience as to loss of 
tonal vitality over time in  strictly crown cut ribs.  May I also suggest the 
variables may not only be  in the laminating process but also the amount of 
crown built in compared to  the crown cut ribs.  Also the density of the wood 
selected for  crown  cut rib will also play a major factor in overall 
stiffness.  One thing  that I try to do is to pick wood of similar grain density i.e. 
not one rib with  wide grain or one with real tight.  I prefer wider grains in 
the bottom 2  bass ribs & then get tighter  as the ribs progress into the  
treble.  I have some very tight & dense sitka right now which would be  hard to 
imagine a laminated rib offering any more support than this.   However 
laminated ribs are glued up in an arch & therefore have a cross  section that is 
continuous unlike the crown cut rib that is thicker in the  middle & tapering 
toward the ends. At least that's the way I've made them.  All this to say it's a 
bit hard to put a finger on this but subjective  evaluation is still relevant in 
my book.
  I do also experience the sound board maturing over time  usually the first 
year
   Thanks
   Dale Erwin

Dale,
The impression I am left with is that over  time the laminated ribs maintain 
the sound it had when it left the shop, where  the crowned spruce ribs, cut to 
the same or similar dimensions as those that  were laminated, seem to loose a 
little dynamic range.  This is very much  based on a small sampling of my 
work.  I still tune some of my first jobs  where I cut the curve into the rib, 
and that is the impression I am left  with.  Now to be fair, I hope that I do 
better work than I did then, or  maybe the glue joint between rib and board is 
better, I can't tell you  why.  Maybe Del has tweaked his designs and now he is 
doing a better  job.  Couldn't say.
Steve  Gaza





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