Guitars do not require heavy maintenance like other instruments do. However, there is one thing that should be taken into consideration when storing them. Guitars are made of wood, and like almost anything made of it, they are vulnerable to moisture.
Relative humidity, a concept meteorologists and guitar lovers should be familiar with, refers to the quantity of water that the air can absorb. The air that surrounds the guitar can affect the wood in undesirable ways if it is not kept on check.
Like anything in this world, each guitar is unique. From the moment they are being assembled, they are exposed to unique humidity conditions. Those initial conditions end up permanently sealed in the guitar once it is finished. It means that every time the guitar is exposed to humidity variations, its wood shrinks or expands unevenly, even though the dimensions of the guitar remain the same.
Controlling humidity and its effects can be frustrating, as the more expensive a guitar is, the more it seems to be affected by relative humidity as they are made completely of solid woods. Moreover, the damages caused by moisture changes can be costly.
The effects of continued exposure to moisture are many. The sound of the guitar becomes muddled or dampened, projecting a lifeless or “waterlogged” sound. The most extreme cases can show signs of bloating when the constant expansion and shrinking of the body causes the layers of wood to detach.
The extreme loss of humidity, on the other hand, can cause the wood to shrink too violently. The stress on the wood can result in cracks along the body, and make the sound brittle and harsh.
There are some things that can be done in order to avoid problems with humidity:
Always keep your guitar in its case. Humidity conditions can vary drastically even in your home. Guitar cases are closed environments that guard your guitar from these drastic changes.
Additionally, it is easier to control the humidity inside of them.
Keep an eye on your guitar. Common signs of damage by high humidity are: swollen portions on the back and sides of the body, cracks on the finish, buzzing sounds when playing the highest frets, dampened sound. Low humidity can be detected if you see cracks or dips in the wood, or frets sticking out of the fret board. If you see any of these signs, try to store your guitar taking the appropriate measures, like using a humidifier.
Watch the moisture. Normally you can tell if the weather is dry or humid, so you can adjust the conditions of your home accordingly. If the weather is too dry, try to get a humidifier or buy some plants. If it is too humid, probably during the hot season, remember that air conditioning is your friend. If possible, get a digital hygrometer to help you read the environmental changes.
Avoid rapid temperature changes. If your guitar is in a cold room and you need to take it to a warmer environment, do not open your case right away. Allow it to sit for a while so the temperature of the case equals that of the room. Drastic changes can severely affect the moisture of the wood.
Know where not to store your guitar. Keep your instrument away from cold damp areas. Your basement is not the best place to store your beloved guitar as it gets cold really fast. Hot and dry air is also a killer. Never place your guitar close to the heating ducts or in front of the air conditioning.
Consider taking care of your guitar as a long term investment. The wood of a guitar is said to “mature” with time, if properly kept, improving its sound and purchase or resale value.