Dampp-Chaser chaos

[Bob Anderson]

There have been so many DC posts that touch on slightly different
aspects of the humidity control issue that I'll take one blast that will
try to cover everything (ha,ha, Good Luck, Bob).

David Pitsch maintains that the DC system affects the whole room, but
then he talks about installing room systems and furnace systems. I guess
I'm not following the logic, but if the DC is conrolling the room,
what's the motivation for the sepa




rate room system?

Does the DC help tuning pin torque in a vertical piano? I have had some
positive experiences, but that doesn't mean that one should recommend a
DC to correct a loose tuning pin situation. This issue was discussed in
a Dampp-Chaser panel at a Calif.St. P.T.G. convention a few years ago.
The consensus was that the increased RH in a vertical piano could
increase tuning pin torque. This assumes  that the RH is too low to
begin with. It also assumes that the torque is on the borderline between
holding and not holding. If we're talking about a Baldwin with a torque
of 200 to 250 inch-lbs. you're probably not going to be able to notice
the difference, etc., etc. The bottom line is: in my experience, I have
had pianos improve tuning pin torque after the installation of a DC
system. I have also NOT observed higher tuning pin torque after a DC
system was installed. It could help, but I wouldn't make it a major
selling point to a customer.

Someone has already mentioned the efficacy of the "smart heater bar". I
just retrofitted one for one of my customers who hadn't had me tune her
piano since 1994. I tried to get back there sooner, but you know
customers. Anyway, the alarming state of the humidifier pads plus my
lecture on the dangers of neglecting piano care combined to lead to a
nice new smart heater bar. The DC system had caused her piano to stay in
tune better than it had before, and she ignored my reminders to get her
piano tuned. At least now the smart heater bar will badger her even if
she ignores my periodic tuning reminders and she will not wait another
four years for a tuning, I bet.  

Going back to my first statement, I haven't observed any DC effects on
any component of a grand piano besides the soundboard. I keep looking. I
keep measuring RH. I have found a hygrometer mounted under the
soundboard reads a lot different than one mounted somewhere in the room.
I recommend room or furnace humidifiers to customers with grands to
supplement the DC systems. I think the DC is the most direct and cheap
way to deal with the soundboard. 

So that is one technician's opinion based on serious attempts to
understand the problem of humidity control.

Bob Anderson
Tucson, AZ