upright flanges with threads

[John Delacour]

At 2:14 PM -0800 1/6/02, Mickey Kessler wrote:

>The piano I was working on the other day was a quite lovely old 
>Gildemeester & Kroeger upright.  The hammer butts have their own 
>little return springs, held by threads attached to the flanges.  (I 
>understand from one of the catalogs I have that Yamaha uses a 
>similar arrangement.)

Very few pianos outside America have spring rails.  I haven't got my 
Schaff catalog here but I'd be surprised if they don't do loop cord. 
What you want is a polyester braided cord about 0.7 mm thick.  If you 
can't get it from the catalogs, try a model shop.  All European 
suppliers have it.  Go to <http://www.pearsalls.co.uk> for 
specifications.

The originals were probably silk.  Silk is fine if it is not exposed 
to moisture, but prologed humidity will cause it to rot.  For 
surgical sutures silk is used to avoid the need for further 
intervention.  Polyester, which is quite inert, is used for sutures 
that will be manually removed.

Clean out the kerfs with a pit of piano wire ground flat at the end 
to use as a scraper.  Cut the cord exactly to length, get some glue 
in the kerfs and press the cord home with a suitable blunt blade or 
the back of a scalpel blade. I'd use hide glue but it's not critical. 
Stroke some glue over the top when the cord is home.

The butt springs should be adjusted so that they just bring the 
hammer back from the string, not allowing it to burble or fall 
forward.  If the springs are set too strong, you will impair 
repetition and increase the touch weight.

JD