[pianotech] Hammer stapling-tone builders corner

[Dale Erwin]

Good pics Lim
 The area where the staples/wire twist ties are inserted, is an area of the felt that has little to no tension or compression. Just stick an needle in it on any hammer and see. The density felt with a needle will be primarily from the density of whatever felt is being used.  
    The side cauls of the press fold in on those areas to insure a good glue joint after the top felt is tensioned and compressed in the steel form/caul. Side cauls  are also generally heated to 130 degrees or so, at least in the Ronsen process,which is actually a good thing as the heat and pressure of the side cauls help the glue dry and also condenses the felt in that region a bit, which is usually quite soft.
 I have ordered and installed many sets of hammers from Ronsen without staples and with no issues. however Ray likes to staple as a bit of added insurance. With tension so high in the Weickert felt we now double staple the first 10 hammers or so.
An old school voicing protocol is to stiffen this area with 3 to 1 Lacquer-acetone/plastic/plexiglass as this area is doing nothing if it is just limp felt. But as a stiffened as described it becomes the bottom foundation & adds support to the top of the hammer to push off of. One rarely notices any tonal effect from this application in and of itself but I notice a solidifying affect in the tone of the Weickert felt hammers quite dramatically...and that was from the very first set I applied this protocol to.
Dale


Dale Erwin RPT-
 Mason & Hamlin/Steinway/U.S pianos
Pre-hung Ronsen hammer sets/Abel parts
Sitka Soundboards & Supplies
WWW.Erwinspiano.com
209-577-8397

 
  





-----Original Message-----
From: lim hock seng <limhseng at gmail.com>
To: pianotech <pianotech at ptg.org>
Sent: Thu, Apr 12, 2012 12:15 am
Subject: [pianotech] Hammer stapling


Hi,
These may be posted before but I just want to contribute.
Lim
 

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