Re: Woodwind Shrinkage

[CLARK FOBES <reedman@ix.netcom.com>]

>From: Scott Hirsch <WQEditor@aol.com>
>
>I could use some commentary.  Let me introduce myself first.  My name is
>Scott Hirsch and I edit a small journal, The Woodwind Quarterly.  (A
>publication directed at repair technicians and makers of woodwinds.) A
>recent article, Grenadilla Wood and the Environment by Larry Naylor, was
>published in our August issue.
>
>The author claims that when an instrument looses moisture, it contracts
>into itself, which would increase the instruments bore diameter. 
>
>Is this possible?  I can't quite see how a wooden tube can loose water and
>increase in diameter.  Boards and wooden squares and all sorts of wooden
>shapes clearly lose size when they lose water content.  Is a tube
>different? Distort and move towards an oval in cross-section maybe, but
>not get bigger. 

I believe that the condition that Mr Naylor describes is true. However,
forget about the tube for a moment and imagine a flat board on edge. If
this board loses moisture equally it will shrink into the center losing
dimension on both sides. Now imagine a cross section of a tube with thick
side walls (like the clarinet). When this cross section loses moisture it
will also shrink to the CENTER OF THE WALL. If it loses thickness
dimension on both sides of the wall the O.D. will become smaller and the
I.D. will become larger. I have found that if clarinets sit foe several
months or years without being played that they drop in overall pitch due
to the larger bore diameter. 

Clark W Fobes  reedman@ix.netcom.com