[CAUT] was caf now seasonal sb failure

[Ron Nossaman]

> As I sat there, I wanted to investigate, does this
> piano need, voicing or new hammers or a new board?

My bet is the board.


> Hammers have been replaced (by a previous tech) and
> aren't that worn.  The SB has a crack in it that is
> definitely more visible during this time of the year. 
> Yesterday when I tuned somewhere here in the area it
> was 28% rh at 71 deg.  Could be a little different I
> suppose from location to location.

The crack itself isn't a problem, but is diagnostic indication 
of compression degradation of the panel.


> #2. The second D, which is bothering me greatly is in
> a church.  It's also a 1970's model.  I put all new
> hammers and wippens in it replacing teflon parts and
> problems about 2 years ago.  I hoped for great
> improvement in tone.  While I got some, the piano
> still lacks power terribly.  I am in the process of
> adding keytop/acetone which is giving some help but
> still not what I want.  When I pluck a string it's not
> much or any different than the hammer strike.  A
> rocker gauge on the bridge of this piano indicates
> there is downbearing. This one has a Dampp Chaser, the
> univ. one doesn't. 

When plucking doesn't give you anything different than the 
hammer strike, there's not much you can do to the hammer that 
will make a difference. Hammers very typically get blamed for 
soundboard dysfunction.


> Do you always check crown/downbearing a particular
> way: under the board with a thread; rocker gauge on
> bridge; thread from agraffe to hitch pin; Lowell gauge
> or other? I used different methods, but wonder which
> gives the best reading. 
> 
> Bob Hull 

I don't think splitting hairs in different ways tells you much 
here. I don't typically go looking for trouble until I hear 
something that indicates it's pre-existence. Then, I check 
crown against bearing to try to correlate the two against what 
I hear in what parts of the scale. A negative crown, with a 
negative bearing, at the same spot that the attack splatter 
and short sustain is happening, is a pretty good indication 
that voicing isn't going to fix it. It's a pretty crude 
yardstick, and isn't something by which you can predict tone 
from measurement, or put a terminal self destruct date on, but 
it's still useful as a fantasy damper and reality check.

Ron N