Lacquer on Aggraffes

[Overs Pianos]

Hi folks,

Sorry I'm a late arrival on this thread.

>Joseph Garrett wrote:
>
>>  Richard,
>>  Hmmmm? Now you got me thinking! It is possible that my cleaning the
>>  termination point, on the aggraffe(s), of lacquer, actually refined the
>>  termination point as well. That is entirely possible IMO. However, I tend to
>>  stay away from anything that might, in the remotest possibility, deter the
>  > sound. I wonder if Ron O has any thoughts on this.

Hi Joe, yes I suspect also the hysteresis loss effect of lacquer on 
agraffe holes. We are now cutting all agraffe holes, whether new or 
original. New agraffes can be just as noisy as the original ones, as 
Roger mentioned. We're now electroless-nickel plating our agraffes to 
a thickness of 0.002" (0.05 mm). This type of plating covers the 
interior string hole surface with the same 0.002" coating. The plated 
surface has an as-plated hardness of 45 Rockwell C, but is further 
hardened by heating to 260 degrees C for four hours. Those of you who 
saw our piano at Reno would have seen these agraffes. All our 
counter-bearing bars are treated with the same plated finish. When 
fitting the agraffes to the plate, we now turn brass washers to the 
individual thou' thickness required to tighten each agraffe to the 
appropriate orientation when tight. This involves tensioning the 
agraffes first to ascertain the degree of anticlockwise rotation 
required, the washer thickness being calculated and parted off. While 
this might sound tedious, its quite quick once you get used to it. 
Furthermore, it allows for the agraffes to be set with a minimum of 
vertical misalignment.

Ron O.
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Website:  http://www.overspianos.com.au
Email:        mailto:ron@overspianos.com.au
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