Pianos in Sunlight

[GABRIEL ZWIERSKI]

Ken:
      Sunlight is definitly bad for piano finishes and plastic keycoverings.
      As an independant polisher/finiisher  who deals primarily with pianos, I
have seen many pianos that were half brown and half green as a result of being
exposed to direct sunlight over a period of time (UV bleaches out reds, red &
green make brown)  with yellow keys. The finish can be fixed (at least
temporarily) and I advise my clients with plastic keycovers  to keep the
fallboard closed when not in use.
       To me,  constant RH (I usually advise in the range of 40%) is is more
important for the general well being of the instrument than UV avoidance.  It's
the RH that causes the wood to expand and contract causing all kinds of problems
(cracked finishes,cracked and/or ridged soundboards, sticky actions etc.
etc...).  Different woods expand and contract at different rates in response to
changes in RH.
      Glass blocks some of the UV (I forget which range) and there are clear
plastic "shades" available (I have seen these, but haven't tracked down a source
yet) which are supposed to be opaque to UV (not advisible if there are plants in
the room ( they need UV to survive)).  The best solution is to keep it out of
direct sunlight.

            Gabriel Zwierski