Moistureproofing shop - now stage box

[Jim Kinnear]

Perhaps its something to do with 'hot air rising' and taking the resident
moisture with it . . . kind of like when we put our wet mittens over a
heater . . .

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Jim Kinnear
www.kinnearpiano.com
Collingwood, ON, Canada

----- Original Message -----
From: "gordon stelter" <lclgcnp@yahoo.com>
To: "Pianotech" <pianotech@ptg.org>
Sent: Thursday, November 04, 2004 12:39 PM
Subject: Re: Moistureproofing shop - now stage box


> Nice explanation, Sarah, but I think a dehumidifier
> dripping to the outside in a sealed box is the best
> way to go. Speaking of which: how do Dampp Chaser bars
> dry out piano parts, as increased heat in a closed box
> such as piano case only allows more moisture to reside
> in the air?
>      Thump
>
>
>      G
>
>
>
> --- Sarah Fox <sarah@graphic-fusion.com> wrote:
>
> > Hi Bob,
> >
> > Dehumidifier bars *alone* won't do it, as the RH
> > will rise in the booth as
> > moisture comes out of the wood.  There has to be
> > some way of transferring
> > the moisture from the inside to the outside.  This
> > can be achieved with some
> > degree of ventillation in combination with the
> > dehumidifier rods.  (In other
> > words, don't have the chamber too air tight.)
> > Fresh, cool air will enter
> > the chamber at some higher RH, and then it will be
> > heated, driving down the
> > RH.  The air will then absorb moisture, and the RH
> > will rise.  But
> > eventually, the warmer, moist air is vented to the
> > outside (the way the
> > moisture is transferred), and it is replaced by
> > cooler moist air, which can
> > be heated to lower the RH.  Put another way, cool
> > air of a given RH has less
> > total moisture than warm air of the same RH.  Makes
> > sense???  If you use the
> > heat approach, you'll find some very cheap and
> > effective ceramic heaters at
> > the hardware store (perhaps $15 for 1000W of heat).
> > There's no need to blow
> > lots of money on dehumidifier rods, and the
> > efficiency is exactly the same.
> >
> > A noisier but more effective way to dehumidify is
> > with a running
> > compressor-type dehumidifier, which will condense
> > the moisture out of the
> > air and drain it to the outside.  I think you can
> > get one of these things
> > for around $150.  I don't know which of these two
> > methods would be more
> > energy efficient.
> >
> > A third way to dehumidify would be with a dessicant
> > in an *air-tight*
> > chamber.  (This might be useful for pinblock
> > material, but it gets somewhat
> > impractical on a large scale.)  There's a
> > product/company called Drierite,
> > out of Xenia, OH.  You can find it on the web. You
> > can buy the stuff fairly
> > economically in 50 lb bags.  Drierite draws moisture
> > out of the air and
> > incorporates it into its crystal composition.
> > Depending on the variety you
> > buy, the stuff can have an indicator that changes
> > color when it has soaked
> > up as much moisture as it is able.  It looks a bit
> > like blue kitty litter
> > and turns pink with moisture absorption.  If I
> > remember correctly, it can
> > absorb about 5 or 10% of its weight in water.  When
> > the stuff is
> > "exhausted," you can heat it in an oven to drive off
> > the water, so that you
> > can re-use it.
> >
> > Peace,
> > Sarah
> >
> > _______________________________________________
> > pianotech list info:
> > https://www.moypiano.com/resources/#archives
> >
>
>
>
>
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