Re: Advice, please! Humidity and Mandolins.
OK -- remember that it's called relative humidity, which means it's the amount of water vapor present in the atmosphere relative to the atmosphere's capacity to hold moisture. Which is why it's expressed as a percentage. Air at a certain temperature can hold a certain volume of water vapor; if the air currently contains as much water vapor as it can hold -- couldn't take another drop -- that's "100% relative humidity."
Now they tend to express humidity on weather forecasts in terms of the "dew point," which is the temperature where the water vapor will start to condense into drops of water. You get dew when the air temperature lowers at night, reaching the dew point, and water droplets condense on surfaces -- grass, car windshields, your mandolin that you left out in the back yard, whatever.
In the winter, the atmosphere around your house is colder; ergo, it can't hold as much water vapor. You suck that relatively low-moisture air into your house, and heat it up with your stove or furnace. That increases its ability to hold moisture, but it hasn't got much moisture in it (because it was cold), so the relative humidity decreases, gets down around 25% or below, and this dry air, with its capacity to hold much more moisture that it has, absorbs some of the moisture from objects in your house -- your furniture, the lining of your mouth and throat, your mandolin that you left out on its stand without benefit of a humidifier.
I usually tell people not to obsess over humidity; just be reasonably careful, measure the relative humidity with a hygrometer, and take normal precautions. Same with temperature; extremes and rapid radical changes should be avoided, but a normally comfortable environment is hardly ever going to damage your instruments.
Allen Hopkins
Gibsn: '54 F5 3pt F2 A-N Custm K1 m'cello
Natl Triolian Dobro mando
Victoria b-back Merrill alumnm b-back
H-O mandolinetto
Stradolin Vega banjolin
Sobell'dola Washburn b-back'dola
Eastmn: 615'dola 805 m'cello
Flatiron 3K OM
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