Klarinet Archive - Posting 000779.txt from 2000/04

From: "redcedar" <redcedar@-----.au>
Subj: [kl] Pinched Reed Fibres (was "Stuff that drives me nuts....")
Date: Tue, 18 Apr 2000 23:33:25 -0400

In response to Adam's comment that his teacher:
"recomended me NOT to get a reed trimmer and she explained to me that the
fibers in your reed are pinched together when you use a trimmer thus you
loose a reed that could have been better."

Walter Grabner responded in part:
"Has anyone here SEEN a fiber that has been pinched together? What does it
look like. How do I distinguish it from a fiber that is NOT pinched
together? What vibrational modes of the reed are dampened but having pinched
fibers? Can you observe a pinched fiber under a microscope???
What is a pinched fiber?"

and in a later post added, in part:
"PLEASE show me a pinched fiber, and demonstrate that the "pinched fiber" is
diminishing the tone of a certain reed."

I am unable to adequately respond to all these points, but quote the
following as an indication that pinched fibres may exist.

The American wood technologist, Professor Bruce Hoadley, in his book
"Understanding Wood" (1981), p. 155, states that in 90-90 degree cutting
(that is cutting perpedicular to the end-grain of wood - and that includes
reed cane), "the cutting edge (reed-trimmer) must sever the chip (waste
reed) by cutting longitudinal cell structure across the grain. The chip is
displaced (severed) as much by shear deformation and failure as it is by
bending... Since the cutting tool must sever fibres across the grain, a
dull edge will drastically deform the wood in compression perpendicular to
the grain during cutting. This may result in severely bent-over fibre ends
and even splits down into the surface of the resulting cut. For this
reason.... sharp cutting edges are essential to minimise damage..." (the
parenthetical inclusions are mine.)

Given the porosity of reed cane, one could reasonably expect that any fibre
deformation suffered, either in manufacture or subsequent trimming when
using a sharp cutting edge, may be subsequently restored when the reed is
moistened for use in playing. However, if the cutting edge was blunt, then
consequential deformation may be permanent and unresponsive to moistening.
Whether one could then argue that such deformation perceptibly diminishes
the reed performance is beyond my knowledge, and for others to answer.

Michael

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