-- Helps the Instrument but Wrecks the House
Our inestimable editor Rhodes sent me a link to a discussion
forum where many heating, ventilating and air conditioning (HVAC)
professionals write about air handling. I learned quite a bit.
The discussions reinforced nearly all my personal experiences.
I have disconnected my Trane Clean Effects unit and will be putting
in a filter.
The extremes of nature quickly reduce even granite to dust. Having
a relatively constant climate is clearly helpful to the longevity of
all materials, and the organic materials are the most fragile.
So why not keep 65 degrees Fahrenheit (18 Celsius) and 45% RH all
the time? It's fine if nature does it for you in some utopian clime,
but when you attempt to create a climate within natural variation,
be prepared to discover the stresses put on the materials in between
your utopian climate and the world outside.
The National Historic Preservation Association has extensive
publications and methods of handling buildings which were not intended
to be preserved in a bell jar. The approach is of protection and
maintenance. Many of the key concepts are quite the opposite of what
we are told by the heating, ventilating and air conditioning industry!
Our house in Idaho had 80-year-old cedar siding with layers of white
paint and was quite crisp and sound. The front door was paneled pine,
stained and varnished on both sides. We disliked having the relative
humidity below 10% in the winter when it was below 20 deg. F. for weeks
on end, so we added a humidifier. The piano said "Thank you!"
Our first clue that all was not well was the half-inch-thick layer
of ice that developed on the inside of the front door. It just grew.
It did not drip. With the humidifier off, the ice simply went away.
We knew we had entered a zone quite outside our experience.
The moisture went through the plaster and condensed on the siding where
it froze and thawed, splitting the siding and blistering the ancient
paint. The contractor who had last painted the house surveyed it and
said it would be twice as costly to scrape, repair and paint the siding
as it would to replace it, and we would have the same problem next
year. The second and third opinions were the same.
If we wanted to maintain the humidity at 30% in the winter we would
have to strip the inside wood lath and plaster, resurface with a vapor
barrier system, reinsulate, replace the siding, and install vapor
barrier outlets, switches and ceiling boxes, excavate the basement
perimeter and back seal, and a few other things in the attic. So we
turned off the humidifier and sided the house in HardiePlank concrete
with a 50-year guarantee.
What can you do to protect your instruments? Don't put them in
a climate with extremes, like in a drafty museum in Montana! They
will disassemble themselves. Other than putting them in a plastic bag
with humidity control in mid-winter, I guess you just have to maintain
them when they show the stress of climate variation, or live in a house
designed to allow constant temperature and humidity without the house
falling apart. This is how serious museums do it.
Those of us who have seen a great number of pianos know very well that
they show a very wide range of condition for their age, and most of the
range can be attributed to the effects of moisture.
For example, there are now three known examples of John Langshaw barrel
organs of the 1780s in the world. One has been restored and is in
Lancaster, England. The barrel paper is badly foxed and the staples
and pins are rather corroded. The rest of the instrument has been
cleaned and restored, perhaps several times. The unit in the south of
England is similar.
(The British Isles are, of course, the home of "Rising Damp",
a culturally established euphemism for black mold which consumes
buildings from the ground up and has its own section in the building
But the John Langshaw organ which perhaps was enjoyed on a British ship
and sold off in California before the Gold Rush looks like a smooth-faced
lad in comparison, with clear, unblemished barrel paper, the shine of
fresh metal on many of the pins and staples, and the yellow pine
showing bright yet.
Is this due to a more temperate climate? Was it left wrapped in a
shawl in a closet for 150 years? My guess is climate.