Wood

[Don]

Hi Ron,

Yes it does follow, because the moisture has to be "driven" out of the
wood. The basic meaning of hygroscopic is *attracts water*. I.E. Sulfuric
acid is hygroscopic--violently so. Wood is just...less violent. This is a
simple matter of semantics. "Takes up and RETAINS water" (my emphasis) is
just that. Moisture wishes to stay in the wood--until the air dryness level
is much lower than the wood. Or until the partial pressure is lower outside
the wood. 

That's why a rain storm can wreck a tuning but it takes longer for dryness
to do the same. The wood lags behind on loosing moisture.

This should be simple to check. All it would take is someone to measure
pitchs on a piano in some strategic areas before a Damppchaser is installed
in a dry time of the year. Then measure the piano a hour, a day, and a week
after the install. Then unplug and drain the tank, and measure in an hour,
a day, and a week.

Shall I do this? Vote here! yea or nay? 

Can someone suggest a better protocol for such an experiment?

At 06:36 PM 2/15/2003 -0600, you wrote:
>
>>Hi Ron,
>>
>>http://www.ca.uky.edu/agc/pubs/for/for55/for55.htm
>>
>>And I quote from the above: "Because wood is a hygroscopic material
>>(meaning that it readily takes up and retains moisture), it is impossible
>>to prevent moisture from entering dry wood"
>>
>>No information on rates--but clearly wood wishes to *retain* moisture which
>>was what I was trying to say in the first place. I.E. it comes out slower
>>than it goes in.
>>
>>Regards,
>>Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T.
>
>
>Hi Don,
>Sorry, but that doesn't logically follow. Sure dry wood in damper air will 
>absorb moisture and retain it until the air MC gets below that of the wood, 
>and wet wood in dry air will release moisture to the air - which will 
>retain it until... There's no indication in the above as to which will be 
>faster - MC differences being equal. Air's hygroscopic too.
>
>Ron N
>
>_______________________________________________
>pianotech list info: https://www.moypiano.com/resources/#archives
>
>

Regards,
Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T.

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