More CC vs RC questions was RE: Killer Octave & Pitch Raise

Richard Brekne Richard.Brekne@grieg.uib.no
Wed, 16 Feb 2005 22:32:36 +0100


 From a California government online  manual about wood characteristics

APPENDIX A. WOOD CHARACTERISTICS

"The primary effect of compression perpendicular to the grain
is compaction of the wood fibers. As the fibers compact, the
load-carrying capacity of the wood increases as the density of
the material increases."


Effect of Moisture Content

"Wood increases in strength as it dries. The strength increase
begins at the fiber saturation point (the point at which the
cell walls begin to loose moisture) and increases rapidly as
drying continues."

"Drying wood from the fiber saturation point to five-percent
moisture will usually double and in some cases triple endcrushing
strength and bending strength....."

......................

As to the stabliizing affect claimed by some that compression along the 
grain has on compression cross grain. It should be remembered that 
compression along the grain has the affect of shortening wood cells and 
makeing them fatter, whilst cross grain compression will elongogate 
these same cells and squeeze them thinner.  So it there is significant 
compression along the grain, the cells effectively have gained 
additional strength in the face of  cross grain compressive forces.

Just a few thoughts for your dinner table

Cheers
RicB


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