warped ebony sharps

[Paul Chick (Earthlink)]

-----Original Message-----
From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf
Of Don
Sent: Thursday, August 18, 2005 2:51 PM
To: PTG
Subject: warped ebony sharps

Hi,

I've come across something new to me. A small Bell
piano (Lesage) where the ebony sharps are warping and
breaking the glue joints.

I'd appreciate any advise on regluing.

Should I trim everything down so the surfaces are
flat? The key tops are flat but the ebony bottom
surface is not. 

Regards,
Don Rose, B.Mus., A.M.U.S., A.MUS., R.P.T.
3004 Grant Rd, Regina, SK, S4S 5G7
Tuner for the Saskatchewan Centre of the Arts

I've seen warped ebony sharps...in a box, not on a piano.  No one could
explain the warping, so I did some checking: 
	Ebony is a very difficult wood to season, with waste running as high
as 50%
	It is prone to checking and warping
	The fewer the yellow streaks in the stock, the better the quality.
	Ebony tends to be a reaction wood.
(Most of this information was from the U.S Forestry Service about 30 yrs
ago.)  I'm not sure how the piano industry made so many good sharps from
this wood.  In short, replace the set if that's feasible.  Gluing the
originals back to the key blank only invites the warping.

Paul C