How the Environment Affects Your Harp
Your stringed instrument lives in two worlds. It is both the hardy companion to your musical bent and a sensitive and fragile set of thin woods under enormous stress. With proper care, your harp should see you through your lifetime and well into the next generation. Here are some tips.
Heat is a serious hazard for all wood stringed instruments. Luthiers purposefully use glues which soften when heated (to 145°F) so that a harp can be disassembled for servicing when necessary. Direct sunlight is hot enough to soften the glues in your instrument and weaken or destroy the joints. Do not display your harp in your bay window unless the sun is never on that side of your home. Do not leave your stringed instrument anywhere that will be exposed to sun as the light moves across your room during the day. Never leave any wood stringed instrument in a car on a hot day. If it is too hot for you to sit in the car, with all the windows closed, in the direct sun, without sweating – it is too hot for your instrument. Car trunks are even worse. The simplest rule of thumb is that the same environments which are comfortable for you are appropriate for your harp.
The only really dangerous element of cold for instruments is a sudden change from very cold (below 40 degrees F, 4.44 degrees C) to very warm. When going from warm to cold or cold to warm, your instrument needs to be insulated. If you have a padded case, use it. Once you arrive at your destination, keep the instrument cased until the outside of the case is at room temperature. If your harp is still icy when you open the case, zip back up and wait a while longer. If you take your wrapped harp from your warm house, to the inside of your warm car, to the warm inside of your harp teacher's home, do not worry at all. It is only when the instrument is left in the cold for a long period that you need to go through an extended acclimation.
Woods swell in high humidity. As moisture creeps into the inner cellular structure it expands. If your instrument is always in a humid environment, it should go through its initial expansion and then stabilize just like any wood furniture in your home. Beware of air conditioners, however. They are not good for woods in the same way they are not good for your skin. If you keep your home bone–dry but live in a humid area, you risk cracks in the instrument's soundboard which Chapstik cannot heal. (See Preventing Cracking for some tips.) If your instrument is moving into a humid region from a dry one, it will require re–tuning. It is better to re–tune often as the piece is going through its expansion rather than to let it sit for several weeks and then introduce a sudden increase in pressure.
As one would expect, low humidity is the reverse of high in terms of the structural nature of woods. Wood will lose so much moisture that it can become brittle and crack. You do have an early warning system. If you need extra lip balm you also need to be paying attention to the local humidity wherever your harp spends its day. (See Preventing Cracking for tips.) The key is moderation and consistency. If you are moving your instrument from a wet environment to a dry one, loosen the strings a half step in tone. If you can, allow harps (especially) to settle in for several days before you re–tune. The harp will naturally stretch the strings and retain pressure as the soundboard falls. Also, if you are living in a dry environment, we strongly recommend a humidifier. You, your furniture and your harp will all be in better condition as a result.