[CAUT] Thumping Baldwin SF

[Don Mannino]

Andrew Anderson wrote:
> I was called to tune a Baldwin SF yesterday.  It tuned up beautifully 
> with a nice really clean treble.
> 
> What bothered me was excessive action noise, thumping on every key.  
> It started to stand out in the midrange so I pulled the action 
> thinking there must be foreign objects or bedding issues.  No FOs but 
> bedding might be an issue, no glides.
> 
> Is this a typical feature of Baldwins or is this likely a bedding
issue?
> 
> Andrew Anderson.

If this is on the release (most common), here is a checklist of
possibilities.  Pick an especially noisy note and check the following:

-Hard knuckles (usually more of a 'clack' noise than thump): test by
running a needle through the core felt from the side a couple of times
just under the flattened spot.
-Hard wippen heel cloth: test by running a needle through the middle of
the thick cloth from the side 2 or 3 times just at the capstan
depression.  This is not fluffing the surface, but softening the cloth
core where it has become compressed.
- Hard back rail cloth: Lift to check if it's glued down at the back
edge, if not rough it up a bit with a screwdriver, curl it up slightly,
or lift it and put a small strip of thinnest bushing cloth under the
back edge and see if that stops the noise.
- Key knock: Balance rail pin holes too loose, balance rail punchings
hard. Take a key out and swab the inside of the hole with boiling water.
Dry it out (takes 2 minutes of waving the key around this time of year,
right?) then ease carefully in the usual way, but leave a snug fit - it
should not fall freely, but should drop slowly down when teased into
motion a little.  This is the dry weather fit, by the way - in higher
humidity it will fall freely.

Room acoustics really influence the perception of action noise as well.

Hope this helps.

Don Mannino