seminar report

[James Grebe]

Hi All,
    Its morning and I will try to relay the high points of some of what I
heard, hopefully learned, at our seminar.

First, I would bestow on both instructors, Paul Revenko-Jones and Alan
Vincent the title of "mechanic" , the highest complement I can address
anybody as.  I would also say that the quality of people attending the
seminar were all high class, attention to detail and their profession, and
show ample proof of the future of piano technology.

    I will first talk about the termination class given by Revenko-Jones.

    He talked about the fact that there are more than just two termination
points along the piano string and not all giving the same type of
termination.  There are 4 types of materials of the materials concerned.
1.  Wood with the characteristics of grain and compression.
 2.  Steel having the characteristics of twist and rotational imbalance.
3.  Brass (agraffes) having the characteristics of casting.
4.  Cast iron (capo and counterbearing) with the characteristic of casting.
He told of his studies in capo termination's as having different shapes
depending on the length of the piano and the quality level and the hardness
thereof.  He talked about false beats and came up with the definition of a
single string having two different vibrational lengths and the beating
caused by the interference of the two frequencies.  He used a small hammer
and brass punch to demonstrate a false beat to get less by tapping the
bridge pin.  You always want to use something softer than the wire itself.

On agraffes, he said that some may use the sandpaper on a string type tool
but what that does is to elongate the hole from round and can cause the
music wire to bind in the hole. This may be where some of that "sizzle'
comes from as well as funny agraffe noise because it is not seated properly.
He uses a little device made from a 4RPM hi-torque motor and chuck assembly
to put in his reamer which he got from PianoTech.  It makes a perfectly
round and counter sunk whole on both sides of the agraffe.  You need to have
the agraffes out to do this.  After reaming, which will make them all
uniform, he polishes them on his buffer wheel with his favorite buffing
wheels and polish.  He showed us some examples and they look literally like
gold.  After polishing and reaming he sprays them with "Brasslac" clear
brass lacquer which comes from Mohawk.  It etches into the brass and doesn't
peel off like other lacquers.  He made a point that each agraffe must be
seated tightly into the threaded hole in the plate at the proper angle
position and he uses the  shims and a reaming tool to ream the plate seat
and shim to come out where he wants to be.  This is more important than the
exact uniform string height from note to note as it won't be that far off to
bother anything.  He never replaces agraffes unless they break or unless
they are Steinways from the one problem era.
     He does not believe in spraying them gold when refinishing the plate,
as it can cause problems in the holes.  He talked about the flattening of
the wire as it goes around hitch pins and the effect it has on the wire in
breakage.He talked about how cast iron and brass have about the same elastic
modulus.  He talked about heat treating the capo and remarked that he
believed that it caused surface brittleness rather than hardening all the
way through.  He takes special care to shape the capo with each restringing
job he does.
He has a videotape that Larry Fine sells that show his rebuilding process.

 Can someone send me the address for Larry Fine so I can order his catalog
so I can order this tape.

    Nest to Alan Vincent's class.  Alan works for Geneva International who
is the Petrof importer.  He showed us how, just since he went to work for
them (3 years), that the piano has been improved in touch characteristics.
They had been using their version of maple ( beech or hornbeam) to make
their keysticks from.  This made for a very heavy touch because of the
weight of the stick itself.  They have now switched to their version of
spruce for the keys and the touch weight has dramatically lessened.  He
showed how the keys were weighed off with his shop made demonstrator.  He
said that touch weight is determined by mass and friction, period.  Friction
is not necessarily the bad part and is really important to have some and in
consistent quantity.  He said that the most important friction point which
affects touch in the action is in the knuckle, jack relationship and he
likes to use Teflon powder brushed in with a toothbrush on all the knuckles.
He also showed the effects of the hammer over and under centering when
striking the strings and what can be done about it.  He talked about plate
positions.
1.  Bass to treble plane
2.  Fore and aft plane
3.  up and down plane
All of these must be taken into account when replacing the plate for
restringing.
Alan uses a system of tooling holes to mark the location of the plate in the
11 o'clock and 2:30 o' clock positions throughout the plate and inner rim.
He also measures keybed to capo height and the position of the string height
on the highest single unison bass wire to make sure when the block is
replaced that all is well  Bottom line is you can't have too many guideposts
to allow you to make sure you are where you want to be.

All in all, for $25 bucks how can you beat free breakfast, free lunch and 2
great instructors and meeting new friends..


James Grebe
R.P.T. of the P.T.G
pianoman@inlink.com
Creator of Handsome Hardwood Caster Cups and Practical Piano Peripherals in
St. Louis, MO