From the January 2017 issue of Acoustic Guitar | BY MAMIE MINCH
Q: What is the ideal humidity level for a guitar? Do all woods require the same level of humidity? Do laminates need the same levels?
—Ted Hechtman, Brooklyn, New York
A: With winter approaching, along with the ensuing use of dry heat to warm your house, it’s time to have a conversation about the potentially detrimental effects of humidity. Maintaining your guitar’s humidity level is key in avoiding lots of headaches, from a fluctuating setup to potentially expensive structural repairs. While it might sound like a hassle, it’s pretty simple to put into practice. The driest time of year varies from one area of the world to another, but most of us need to think about it when the heat goes on and the air in our homes is much drier. Did you ever wake up with a dry mouth or irritated sinuses in the winter? Imagine how unhappy that makes your guitar!
You can start by considering where you generally keep the guitar. In a way, it’s really safest to stash a guitar in its case—no enthusiastic tail wagging will knock it off it’s stand, no tipsy dinner guest will take it off the wall to show you their Chuck Berry impression. (Wait, that’s just my friends?) Personally, I find that I’m always more likely to pick up a guitar and play when I have one out and ready, and that’s the most important thing to me, so I keep my beat-up 1930s Kalamazoo hanging on the wall in my living room year round. But that makes it subject to the dry humidity.
It helps to know the relative humidity of the place where you keep your instrument. Buying an inexpensive digital hygrometer is a smart way to find that out- I keep one on a bookshelf near my hanging guitar. A good set of numbers to aspire to is 50 percent humidity at 70 degrees. Many of us would have a hard time making that a reality, so do what you can—generally 40-60 percent humidity is optimal. To help maintain that level, I keep an inexpensive humidifier running in that room in the driest months. Once you get into the habit, it’s not hard to remember to refill the humidifier each day—in fact, I notice that I feel better with a higher relative humidity in the air, too!
If you will be keeping your guitar closed in its case, the concerns are a little different. There are lots of great in-case humidifiers available and some cases even have them built in to the lid. The gel-based ones are fantastic in that you have to think about them less often—just be careful when refilling them, and be sure to check on them every once in a while to make sure none of the gel has tipped out. The sponge variety are probably the safest, but they absolutely need to be refilled every two to three days—you don’t want a dry sponge in your guitar sucking up the moisture, since that would be counterproductive.
So do all guitars need to be humidity maintained?
Yes, even solid-body electrics and acoustic guitars with laminate or composite back and sides need a helping hand. For one, they all have wooden necks and fingerboards—a telltale sign of dryness is your fret ends poking out when a fingerboard shrinks. Many newer guitars with composite backs and sides still have a solid wood top, a wooden bridge, and a wooden fingerboard—all of which can crack and separate when they fluctuate at different rates with humidity change. Some guitars will be more sensitive to humidity changes than others—those guitars, especially new ones constructed with kiln dried wood, go through a more sensitive first few seasons and then become more stable.
The takeaway is that, yes, you should humidify your guitar, and no, it’s not that complicated. Once you have that under control, you can get back to the good part: playing it.
Mamie Minch is the co-owner of Brooklyn Lutherie and an active blues player. She is the former head of repair at Retrofret Guitars.
This article originally appeared in the January 2017 issue of Acoustic Guitar magazine.