Some interesting historical information with regard to expanding action brackets:
1942-03 Tuner's Digest:
DIE CAST, GRAND ACTION FRACKETS
By J. M. KINGSBURY, President Wisconsin Division
Some 15 years ago, a number of grand
piano actions were manufactured and
mounted on brackets, moulded of die-cast
metal.
My advice to tuners, who come across
this type of action is, change to cast
iron brackets. Actions of this age using
die-cast brackets will usually be found
in poor regulation, due to warping of the
metal. Regulating the action and leaving
the old brackets on will do no good. The
work will have to be done over before
"many moons."
1950-11 The Piano Technician
Just had a most pleasant surprise visit
from Errol Crowl, president of the Boston
Division, at my home and basement shop.
He was accompanied by a gentleman who
manufactures textile machinery and who is
a master mechanic. I took them down into
my shop - cluttered up as it is - and we
discussed an action in which I was installing
new brackets to replace the expanding
(die cast) ones. The gentleman explained
that it was the Antimony used in the alloy
that caused the expanding and cracking.
I showed him some other ones that had
not expanded so much and he said they had
used Aluminum as an alloy and if they had
used all Aluminum the brackets would have
been stable.
-------------------------------------------
Paul Brown
Vancouver BC
604-324-7013
-------------------------------------------
Original Message:
Sent: 04-27-2013 10:54
From: Jon Page
Subject: Young Chang G-150 # G106657
In my notes, '90-'94, serial numbers starting with: 00
-------------------------------------------
Regards,
Jon Page