Nothing can kill a great guitar faster than dry air. Dry air makes us sick and dry air destroys our guitars. Wood likes to be moist — but not too moist — and in my experience a guitar can handle too much moisture much better than it can handle too little water in the air. Dry wood tends to crack. Moist wood tends to swell. Keeping my guitars properly “watered” is one of the ongoing dedications of my day — and checking the water content of the air is as regular a practice for me practicing Jimmy Bruno’s Five Fingerings.
I use a hygrometer to monitor the air in my house. Guitars seem to like between 40-60% humidity with 50% humidity being the sweet spot between too much water and too little.
If the air is too dry, I need to add water. I use a small “Invisible Mist” humidifier that does a great job, but it can take six hours to add 2% of moisture to the air. If there’s too much water in the air, I turn on my fans. The greatest days are when it rains and I can simply open a window to quickly “humidify” the air as needed by raising or lowering the window. It is much easier to take moisture out of the air than to add it, so I’m careful to watch my percentages — one fan set on high can remove 3% of moisture from the air in 20 minutes.
I am vigilant about this because of a story Arlen Roth told on his Gibson.com blog. Someone had given him several hundred-year-old guitars and he’d opened them up in his music room and the next day he heard a heart-sinking “thwack!” that he feared he recognized as the sound of a guitar top splitting in two.
Sure enough, Arlen saw one of the tops of his gifted guitars had cracked because of low humidity in his music room. Arlen warned us that when you’re dealing with old, unknown, guitars, you need to acclimate them to your environment. That process can take a day or two depending on your current moisture levels. Arlen also said he had mismanaged his guitar room because it was too dry for those old guitars.
One safe way to acclimate a new guitar to your home is to keep it in its shipping box and let it “sit there” in your properly hydrated music room for 24 hours. Then, take the guitar — still in its case — out of the shipping box and let the guitar sit unopened for a few hours. Next, unlock the guitar case latches and prop open the lid an inch or so and keep it open like that for another few hours.
Finally, lift the guitar case lid and enjoy your new guitar!
I confess few of us would ever be able to wait a day and a half to take a look at a brand-new guitar purchase — but in the case of the 100-year-old example Arlen Roth mentioned — I think we owe that patience to the provenance of the guitar.