Dampp Chaser and Grand Action

[Richard Strang]

I mounted a 25 watt rod in the same place and it was not enough for the
climate here. The piano is in a church and is kept closed with a floor
length cover. A second rod seemed to do the trick, but they have not called
me back. Hmmmm.

Richard

-----Original Message-----
From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org]On
Behalf Of DCrpt@comcast.net
Sent: Tuesday, August 26, 2003 7:35 PM
To: davidlovepianos@earthlink.net; Pianotech
Subject: Re: Dampp Chaser and Grand Action


      I was trained in Dampp Chaser installation by Wendall Eaton.(Well
known
consultant and Dampp Chaser distributer back in the 80's).He taught me to
cure
sluggish keys and action centers in a grand by mounting a 7-F (15 watt)on
the
underside of the keybed just in front of the top of the pedal lyre and of
course connected to a humidistat.I have done this on many installations(most
all with complete systems)and have not seen any problems in over twenty
years.The principle of heat rising through the key bed helps keep the keys
and
action dry with out heating the pinblock.I have found it also stabilizes
Stienway key frames so the glides stay regulated.
       I will add that it is an absolute no no to put a rod of any wattage
inside the action cavity.                          Robin Olson  RPT  Wash DC
        P.S. for some reason my e-mail server does not include my return
adress on replies to the ptg list.Sorry if that bothers any of you.
> I don't know what's so complicated about this.  If you treat the centers
> when the humidity is high, then when the humidity drops they will be too
> loose, if you treat the centers when the humidity is low, then when the
> humidity is high they will be too tight.  If you address the centers when
> the humidity is medium, then when the humidity is high they will be tight
> and when it is low, they will be too loose.  This is know as the
Goldilocks
> theory in physics.  IMO it would be better to treat the humidity so that
> anything done to the centers will not be subjected to further swings in
> humidity.  The question being posed, is whether or not that can be done in
> such a manner as to not harm the block.
>
> David Love
> davidlovepianos@earthlink.net
>
>
> > [Original Message]
> > From: <JIMRPT@aol.com>
> > To: <davidlovepianos@earthlink.net>; <pianotech@ptg.org>
> > Date: 8/26/2003 2:45:09 PM
> > Subject: Re: Dampp Chaser and Grand Action
> >
> >
> > In a message dated 26/08/03 1:40:25 PM, davidlovepianos@earthlink.net
> writes:
> >
> > << If sluggishness were the only problem then it could be treated, but
> since
> > the problems come from changes in humidity, then treating sluggishness
is
> > only as good a fix as the humidity is constant. >>
> >
> > I am lost here...care to expand a little?
> >
> >
> >  <<What I am trying to treat
> > is changes in friction that come with humidity swings.  Addressing the
> > action centers won't accomplish that. >>
> >
> >  Gonna defy the laws of physics? :-)
> > Addressing the action centers is the best way to address "changes in
> > friction" as this is where most of the friction changes happen during
> humidity swings.
> > There are other, lesser, causes of friction change but the centers are
> the
> > most amenable to correction.
> >
> >
> > <<" The humidity needs to be regulated
> > in some manner. >>
> >  Or as an alternative the piano needs to be made to work across the full
> > spectrum of humidity swings.
> >
> > << Convection problems could be treated by closing the lid of
> > the piano when not in use.>>
> >  Not really. A string cover would help more.
> >
> > <<  Speculating on the potential problems is easy,>>
> >
> > Well I make a pretty good living by replacing pinblocks and restringing
> > pianos where a piano tuner installed a DC to "solve sluggishness
> problems" and that
> > ain't speculation.
> >
> > << I would guess that the low
> > conductivity of wood would render a low wattage heater bar relatively
safe
> > if located below the level of the flanges on the action bracket. >>
> >  OK........ go for it! :-)
> >
> >  Terry's thought about putting a DC under the keybed and placed under
the
> > action has some merit. At least the convection would happen in the
> correct area.
> > Jim Bryant (FL)
>
>
>
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