The effects of humidity (or the lack of) on an acoustic guitar.

Mark Wein

Grand Poobah
Staff member
This is my students Martin acoustic. He just got back from a gig in Las Vegas and the climate change from there to here exploded the solid spruce top of his guitar.

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I don't remember which model it is, but I think its solid top/laminate sides and back so it's not too expensive but it's still a giant drag. Out of the 4 acoustics that he gigs with I think the best sounding one is an Epiphone Masterbuilt.
 
I don't remember which model it is, but I think its solid top/laminate sides and back so it's not too expensive but it's still a giant drag. Out of the 4 acoustics that he gigs with I think the best sounding one is an Epiphone Masterbuilt.

I love the Masterbuilt acoustics. Terrific sounding models an not just in a "bang for the buck" situation.
 
I'm pretty sure I could throw my Fender Catalina out of the 3rd story window, then put it...un-cased...into the cargo hold of an airplane to the south pole, and it would still be in tune.

Plywood FTMFW!!!!
 
Hmmm....

I'm not sure a climate change from Vegas to LA would cause that unless the guitar was in a really cold room then got really hot very fast, but usually that will only cause finish checking. How old is the guitar? I would think that the humidity in SoCal is good enough that the guitar would not need a humidifier, but if you have had a dry winter that could do it. That is a 'drying too fast' crack. If it is a less expensive Martin then they probably do no dry the spruce quite as well than with the more expensive models and the wetter wood drying too fast is what would generally cause that type of top crack. Living in Denver I always case my acoustics and keep them humidified as well - especially in the winter.
 
Why is important humidity for an acoustic guitar??

I have one and I wasn't aware of this...

wood expands and contracts. your guitars will always play differently depending on the season because of this. in the winter, your home loses humidity because you're kicking dry heat into the air. so the guitar will lose or gain water content based on it's surroundings. while this affects electrics to a certain degree, it's not as much as acoustic guitars. this is because an acoustic guitar isn't completely sealed. while the outside might be painted, the inside of the box is bare wood. so by using a soundhole humidification system, you can keep the right amount of moisture in the box so the top doesn't crack.
 
Before retiring I lived in Vegas for 15 years. I used to keep all of my guitars in a 10'x10' bedroom with a 14 gallon floor model humidifier running 24/7. One day while I was at work my power went out and in about an hour or so the temp. in my guitar room went from 72 to 110 degrees. At the same time the humidity went from around 45% to 0%. By the time I got home my Taylor 810's top looked almost exactly like your students. $500+ for a top replacement by Taylor.

I live near the beach in California now where the humidity averages about 70%. More recently I took one of my solid body guitars from So. Cal. to Vegas to give to my Son in Law as a gift. It went directly from my air conditioned truck to his air conditioned house with no radical temperature shift. Never the less even that solid body guitar developed hair line cracks along the fret board binding within 3 days. Remember we are talking about a place that when you get out of your swimming pool your body will completely air dry in less two minutes. Here's my advice.

Vegas is a humidity war zone for guitars. Don't take them there.
 
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I was concerned about my D-18 when I moved to Phoenix from the Bay Area, but I haven't had any issues. The edges of my pickguard have begun to raise, but that is due more to the aging plastic and not a humidity issue. Even necks will dry and shrink here over time, exposing the sharp fret ends. There's not much you can do.
 
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