Heat, Cold and Humidity: How to Protect Your Guitar
As the heat wave is sweeping across Europe, musicians are faced with more challenges. Your instruments don’t like this weather just as much as you don’t. So how should you protect them? Obviously, it all depends on the type of the instrument. In this article I will focus merely on guitars, but the advice should be relevant for all other wooden instruments.
To keep the guitar playing and sounding as the builder intended, you must maintain an environment within a specific climate range. Generally speaking, if a human is comfortable, a guitar is comfortable.
To put it simple: guitars that get too dry crack; guitars that absorb too much moisture well and buckle. Those are the physics of wood in general. But for a guitar, heat is worse than cold, so keep the guitar out of the sun and avoid leaving a guitar in a hot car trunk all day.
Keep the guitar in an environment near standard room temperature (20-25°C) and the relative humidity at about 50 percent, and you’re never going to hear your guitar complain. If either humidity or temperature get far away from these factory conditions, your guitar is in danger.
A rapid change in temperature or exposure to cold can cause small cracks in the finish. These are called lacquer checks. A gradual increase in humidity won't generally do permanent damage to your instrument. But when very high humidity is combined with high temperature, glue joints could weaken and may even open slightly. If your guitar is exposed to high temperature or humidity for any length of time, the glue under the bridge could weaken causing the bridge to pull off.
Don't set your instrument next to a source of heat or hang it on a wall where it will dry out. At all costs, avoid hanging your guitar on an outside wall during winter months. The wall will be cooler than the inside air. The result is a conflict between the temperature of the top and back, with potential damage as a result.
Should the guitar be exposed to freezing temperatures, let it warm to room temperature while still in its case. This lets it come up to room temperature more slowly, decreasing the possibility of wood and finish cracks.
Do not store it somewhere that is not climate controlled like a basement, crawlspace, attic or somewhere like that. This shouldn’t be a concern if you are playing consistently, but even if you just take a long holiday that is enough time to cause some problems.
If the weather is too strong to battle only with some common sense, there is external help you could use:
Guitar humidifier: This item is simply a rubber-enclosed sponge that you saturate with water, squeeze the excess out of, and then clip onto the inside of the sound hole or keep inside the case to raise the humidity level.
Desiccant: A desiccant is a powder or crystal substance that usually comes in small packets and draws humidity out of the air, lowering the local relative humidity level. Silicagel is a common brand, and packets often come in the cases of new guitars.
Hygrometer: You can buy this inexpensive device at any hardware store; it tells you the relative humidity of a room with a good degree of accuracy (close enough to maintain a healthy guitar anyway). Get the portable kind (as opposed to the wall-hanging variety) so that you can keep it with your guitar.
Good luck in this battle against the Maltese heat! Don’t forget to protect not only yourselves but your instruments as well!