Bridge Capping Materials: Ebony?

[Overs Pianos]

At 10:23 PM -0800 1/12/05, Jurgen Goering wrote:
>
>Ulrich Sauter showed me the titanium bridge pins Sauter is now using 
>(only) on their concert Grands.  The idea is that titanium is 
>extremely hard and therefore conducts vibrations readily.  As well, 
>its low density and low elasticity give it ideal vibrational 
>characteristics for bridge pins.
>. . . I was thinking that if there be interest from rebuilders to 
>try titanium bridge pins.


>  At 6:53 AM -0600 2/12/05, Ron Nossaman wrote:
>
>Without some indication of an actual performance advantage, I don't 
>think I would. I would be interested to see how these pins are 
>marked by the strings over time, and how the combination of cap and 
>pin ages as a termination.

Hi Jurgen, Ron  N and all,

The question of bridge pin hardness, or its deformation or lack of, 
with respect to perceived tonal advantages, is interesting. Early in 
my career my first experience with substituting the standard mild 
steel pins with something harder (hi-carbon tool steel, or silver 
steel) lead me to suspect that a harder pin yielded a brighter and 
cleaner tone.

Recently, we pulled down the Baldwin SD-10 that we first rebuilt in 
1988. I had forgotten that we made the bridge pins from silver steel 
for this piano. This instrument, following its 1988 rebuild, was one 
of the cleanest sounding pianos. Interestingly, when we pulled the 
bridge pins on Friday the silver steel pins had a very small 
indentation only. I am inclined to suspect the harder pin, which is 
more resistant to deformation, yields a cleaner tone. We are 
currently setting up our own Electroless Nickel (EN) plating bench 
since I have been dissatisfied with the contract work and turnaround 
time from the local plating shops. We have one excellent plater here 
in Sydney, Qantas airways plating shop. They do beautiful work but 
they won't take in outside jobs.

Anyhow, we are planning to EN plate a set of bridge pins and heat 
treat the plating for the Baldwin fit-out. This will give the pins a 
hard coating with a low friction coefficient and excellent corrosion 
resistance. We've just completed a Kawai KG6 rebuild where we 
increased the EN plating of the agraffes from our previous 2, to 3 
thou. This plating thickness has resulted in the first set of plated 
agraffes that I've been totally happy with. I suspect that for some 
of the agraffes with the earlier 2 thou of plating, the wire was 
crashing through the plating into the softer brass beneath.

A couple of months ago I inspected some standard steel bridge pins on 
a grand that I had only recently re-strung (I had to re-cut the 
unplated agraffe holes again since they had developed noise when 
freshly re-strung). I was shocked to discover severe deformation of 
the pin at the point of wire contact (the piano was so freshly strung 
that it wasn't fully tuning stable). This has convinced me to try EN 
plating the bridge pins for the SD-10's second rebuild. If I'm happy 
with the result I'll EN plate the bridge pins for piano no. 6 which 
we're taking the 2006 Rochester national PTG convention in June.

In summary, I agree with you Ron N. We certainly need to convince 
ourselves that there is a genuine performance advantage in using 
harder pins. However, I suspect that this idea just might have legs. 
Well see very soon.

Ron O.
-- 
OVERS PIANOS - SYDNEY
    Grand Piano Manufacturers
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Web http://overspianos.com.au
mailto:ron@overspianos.com.au
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