Old man winter is here so it might be a good time to rethink your
guitar maintenance routine; especially if you own an acoustic. I
often tell my students to treat their guitar as they would treat
themselves. In other words, if you're comfortable, chances are your
guitar is too!
Most musicians realize how important it is to protect their
instrument from becoming too hot during the summer months. For
instance, it's not a good idea to leave your guitar locked in a hot
car all day long while you're at work or school. Heat can dry out a
guitar pretty quickly which may cause the wood to shrink and crack.
High temperatures combined with high humidity may cause the wood to
swell and the joints to separate. One of my students is currently
using a borrowed guitar that has a big gaping hole just below the
bridge. The face is warped and separating from the side which is
probably due to one or all of the reasons mentioned above. It's still
playable, but doesn't sound or look very good.
A guitar humidifier placed inside the sound hole can help prevent
drying, but it's important not to over-due it. I read about someone
who kept a humidifier in their guitar inside a closed case and mold
began to grow on the wood. Once mold begins to grow it's very
difficult to get rid of. So don't store your guitar in a damp room
either. If you must put it in storage however, take it out of the
case once in a while to make sure there's no moisture collecting on
it....

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