Over the past month, weather in my neck of the woods has gone from blistering frigid conditions to cold rain and snow then morphed into sunny and warm with a chance of rainbows. Consistent streaks of weather rarely run through the mid-Atlantic and the bi-polar weather patterns definitely have an affect on peoples moods and tudes as well as our guitar babies. Wood moves when humidity changes and understanding how wood responds to changes is a great way to ensure less time at the guitar repair shop and more time making music.
Lets start with some basics. Humidity is the amount of water or moisture in an environment. Absolute humidity (expressed in grams) is the actual amount of water vapor in the air regardless of temperature. Relative humidity (expressed in percentage) is the ratio of moisture in the air at a certain temperature to the potential amount of moisture that could be held in the air at that same temperature. Winter time brings along with it cold air which holds less moisture. When the already cold air outside creeps into our homes and is heated, relative humidity drops below what guitars can tolerate. Necks are going to move, tunings go out and setups will get wacky unless water vapor is added to the environment and kept at consistent levels.
Guitars sense these changes in humidity and the delicate pieces of wood glued together that make up your acoustic and electric respond accordingly. Wood is hygroscopic. That’s fancy word meaning it acts like a sponge. When a sponge is dry, it shrinks. When a sponge is wet, it swells. The thin pieces of wood that make up instruments do the same thing. Here are some signs your guitars might be drying up due to dehumidification
- Buzzing caused by low action
- Open string buzz
- Fret ends poking out the side of a fingerboard
- Acoustic guitar soundboard sinks stressing the bridge seam
- Tuning instability due to headstocks shrinking and loose tuners
- Fret buzz at body joint
- Cracks beginning to form or worsen
If you notice any of the common symptoms of a dry guitar, take action right away! Start by monitoring humidity levels in your home or jam space. Newer homes may have humidification monitor already built into there thermostat or you can pick up online for cheep. Once you find out where the humidity levels are in your home (Ideally between 40-50%) decide if a room humidifier will do the trick or if it would be more beneficial to go with a case humidifier. Both systems work well but they are only as effective as you are with diligently refilling which ever method you’ve chosen. A humidifier is only good if it’s filled with H2O. Make it part of your daily routine! I fill mine twice a day.
Watch on Youtube Homemade guitar humidifier using common household items
Cracks are a big concern when it comes to humidity changes so give your guitars a once over and check for any unknown damage or cracks. They’re often an easy fix when addressed promptly but if ignored can become a more complex repair. The popularity of highly figured tone woods also adds to the likelihood of damage when drastic changes in humidity occur. If wood is not properly dried before construction splitting at the joint or seam is likely to occur. Some of the tolerances for plates used in acoustic guitar construction hover around a hundred thousandths of an inch. Bracing provides strength however tops, backs and sides should still be considered delicate pieces of wood. If you spot a crack, reach out to a repair shop and have it checked out. For minor fixes, re-humidifying the instrument and installing a couple cleats ensures the compromised area will not worsen with time and seasonal changes.
Another precautionary measure to weatherize your instrument is to make sure fingerboards and bridges are conditioned sufficiently. If you can’t recall the last time your board was oiled, it’s time. Conditioning a fingerboard just means taking a bit of oil (an array of products on the market) on a cloth and applying it to the fingerboard. This can be done every couple moths during string changes or set ups. If you’re rocking a maple board that’s finished then feel free to skip the oil but rosewood, ebony and any other unfinished wood needs the juice from time to time.
Woods great. It’s strong, beautiful, varies widely, abundant and bountiful but I think what drives my appreciation for the material is that it’s organic. It’s natural. Despite its strength and beauty wood and the instruments made up from it are vulnerable to the elements and the great test of time. One of my many teachers once said “Sometimes wood still likes to act like a tree” as if to say the pieces that make up our guitars somehow instinctually remembers what it was like living as a tall, beautiful tree growing in the forest rooted in the jungles soaking up the fresh air and the moisture the rain storms brought. He was right.
So when winter time rolls around and we feel that familiar seasonal shift remember so do the guitars. When the heat goes on bust out those damp-its and case humidifiers. In a sense guitars are very much still a living breathing object with their own unique voice and maybe even little soul. Take care of them and they will take care of you. -SB