[pianotech] Mildew

[Noah Frere]

Thank you for your informative post. I believe the problem was singular.
Perhaps it was a long gradual build-up of mildew over many years.

On Wed, Oct 20, 2010 at 5:27 AM, <david at piano.plus.com> wrote:

> The bags of dessicant (usually silica gel) referred to are going to be of
> very little use in this application.  They are ok for inclusion in
> packaging for an item in transit, but not much else.
>
> It's crucial to know whether the conditions that gave rise to the mildew
> in the first place, have been altered.  If not, any cleanup will be only
> temporary, and the mildew will take hold again in due course.
>
> Mildew thrives in damp conditions.  Why might a room be damp?  Various
> factors come in to play.  One might live in an area with a very humid
> climate. One might live in an area with a very rainy cool damp climate
> (like me in the West of Scotland).  Ordinary activities in a home generate
> moisture and put it into the air - moisture from baths, showers, laundry,
> etc.  Simply lying in bed asleep at night, we exhale about 20 fluid ounces
> of  water.
>
> Where does this moisture go?  The warmer air is, the more moisture it can
> hold.  When warm moisture-laden air finds its way into a cool room in the
> house, lots of the water in the air will condense out onto surfaces in the
> room.
>
> Thus if there is a "front parlor" that's only occasionally used, and not
> generally heated, and that's where the piano is, the piano will be a prime
> target for condensation and mildew.
>
> Probably the simplest and most effective way to deal with moist air in a
> home, is to buy a domestic dehumidifier.
>
> These electrical appliances cost pennies a year to run, and very
> effectively remove water from the air in a home.  I speak from personal
> experience, and I believe that no home in te West of Scotland should be
> without one!
>
> An illustration of how things can change in a home was provided by friends
> who are also clients of mine.  They are accomplished musicisns.  Their
> grand piano is in the Front Room, which is not their usual family/sitting
> room, and is not kept heated.  For many years, they had an open solid fuel
> fireplace in that room, and no problems.  Then, they blocked up the
> fireplace and fitten an electric heater. All of a sudden the room smelled
> musty and the piano strings started to rust!  Why?  Because, previously
> the open chimney provided an escape route for moisture-laden air floating
> in from elsewhere in the house, and circulation of  air was able to take
> place.  Now, with the fireplace blocked, any moisture-laden air getting
> into that unheated front room, was shedding its load of moisture by
> condensing in the room, including the piano.
>
> In a cool damp climate, when it's raining outside, opening the window to
> circulate the air won't help, as the air outisde is much wetter than that
> inside.  The solution for my friends was an electric dehumidifier.
>
> 25 years ago, I slept in a bedroom that was getting increasingly mildewed.
> It was not centrally heated and was on an exposed corner of the building.
> Electric dehumidiefers were not as well-known back then, and relatively
> expensive.  But I got one; an excellent, whisper-quite little unit, a
> Toshiba Mini-Dry.  In the first 48 hours of its opereation, I measured the
> water it extracted from that room alone (there was draft-excluder sleaing
> the door).  The little Mini-Dry extracted FIVE QUARTS of water from that
> room!  And that excellent little unit is still going strong today.
>
> Anyway, this is just to point out that the conditions in the lady's home
> need to be assessed and addressed, in order to permanently prevent any
> recurrence of mildew.
>
> Best regards,
>
> David Boyce.
>
>
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