Dampp-Chaser in action?

[Andrew and Rebeca Anderson]

I service pianos in a rather humid climate and I do install heater 
bars under the keybed.  There isn't much air communication between 
the bar and the action cavity (rod holes only) but the keybed does 
stabilize (no seasonal action bedding problems anymore) and I know 
there is some additional benefit in the cavity especially when the 
piano sports a string-cover as well.  I haven't had seasonal action 
center problems crop up again.

Andrew Anderson, Artisan Piano



At 08:37 PM 8/11/2007, you wrote:
>Too many pinblock have been destroyed by DC in the action cavity.  Take it
>out.
>
>How effective can a DC be under the keybed?  Maybe in an old S&S with
>expansion gaps in the keybed, butI think not, with a 40-50 mm laminated
>panel for keybed.
>
>Does anyone have experience with Moisture King products?  In DC the copper
>wire is wrapped around a glass rod and is very fragile.  I have seen many
>of them fail.  In MK the heating element can be removed from the rod and
>tied in a knot and still work fine.  They also have a model that is
>somewhat like a man's belt, flexible, and design to lay between the front
>rail and balance rail under the keys, more to protect the key bushing from
>moisture than the action.  Has anyone had experience with this product?
>And, what about using this in a piano with other electronics also installed
>in this area, such as Quiet-Time key switches?
>
>Frank Emerson
>
>
> > [Original Message]
> > From: John Formsma <formsma at gmail.com>
> > To: Pianotech List <pianotech at ptg.org>
> > Date: 8/11/2007 2:33:46 PM
> > Subject: Re: Dampp-Chaser in action?
> >
> > Right, because most of the heat goes up and out and wouldn't be
> > effective at the action.
> >
> > In theory, grand actions might benefit from a rod or two under the
> > keybed. However, I'm not so sure how it would be in real life.  Any
> > official Dampp-Chaser studies to show one way or the other?
> >
> > My thinking is that sticking action parts are indeed affected by
> > higher humidity, but the root cause is tight centers.
> >
> > JF
> >
> > On 8/11/07, Jon Page <jonpage at comcast.net> wrote:
> > > On pianos which had a DC on grand keys, the pin blocks failed due to
> > > the drying.
> > >
> > > If the purpose is to keep the action dry in a damp environment then
> > > install the DC
> > > under the keybed and let the heat rise that way. Directly under the
>block...no.
> > > --
> > >
> > > Regards,
> > >
> > > Jon Page
> > >
> >