Thousands of homes, schools, concert halls, music stores and practice rooms have wood instruments just lying there. People have done this for centuries. What many fail to realize is the damage that ambient conditions may cause and the importance of humidity control for musical instruments. By knowing the ideal conditions in which to store instruments and implementing them in your facility, you will take strides in preserving their quality and tonal integrity.
Basics about Wood and Moisture
Wood is an organic material that responds to the moisture surrounding it. When there’s a significant amount of moisture in the air, or relative humidity levels are high, the wood absorbs it and swells. When the air is dry, the wood contracts as the moisture evaporates. In older homes made of wood, you can hear this happening throughout the day as the lumber creaks with temperature and humidity changes.
As the wood swells and shrinks, the parts under tension, such as guitar tops, are vulnerable to cracks. Seams and joints are also likely to fail. When moisture levels are high, wood is less resistant to bending and more vulnerable to deformation, sagging and distortion. A mere 20 percent increase in relative humidity levels can cause a guitar to expand or contract by a 1/8 inch. Instruments, however, are more than just wood. They may contain strings, glue, felt, leather and metal components. Changes in humidity affect an instrument’s regulation, friction and feel. Condensation on metal parts promotes oxidation.
In pianos, high relative humidity levels cause significant changes in the instrument’s soundboard. When the environment is too dry, the soundboard shrinks, reducing the crown and decreasing the pressure against the strings. This causes the pitch to drop noticeably, particularly among the center keys. When humidity levels rise back to optimal conditions and cause the wood and various components to assume their ideal sizes, the average pitch of the strings will return to normal, but the exact pitch of the strings will change because their tension changed. Incidentally, a stationary piano will only stay in tune as long as relative humidity levels stay constant. Other problems that could occur with wooden instruments when relative humidity levels are not constant include warping and the deterioration of finishes, wool and leather components.
Ideal Conditions for Storing Wood Instruments in Your Facility
Protecting the Instrument
A wooden instrument should not sit out in the open unless it is on display. When storing an instrument, it is a good idea to clean and polish it first. Place string instruments in hard-shelled cases. When storing pianos, cover the keys with a cloth and close the keyboard cover to keep it dust-free. Then place a blanket or cover over the piano to protect it from dust.
Humidity Control for Musical Instruments
The area in which you store wooden instruments should be away from direct sunlight and areas that expose them to extreme temperature and humidity changes, such as doors, windows and vents. The ideal relative humidity level is between 40 and 60 percent, depending on your geographic location. Some experts recommend using a humidifier, dehumidifier and a hygrometer to monitor and control the conditions in a storage area. However, the last thing you want is for changes in relative humidity levels to go unnoticed. After all, no one wants to go to the warehouse to turn on a dehumidifier if there’s an unexpected storm in the middle of the night.
A better solution is to use custom humidity control solutions that monitor ambient conditions and automatically respond to environmental changes, such as the ones Polygon custom designs. These solutions control the environment in the areas that you specify, allowing you to use the HVAC system to keep the occupants in the building comfortable. The monitors in the equipment ensure that temperatures and relative humidity levels remain optimal. If there is a problem, the devices can send you an alert, allowing you to be proactive about the instruments in your care. Get in touch with Polygon today to learn more about our custom, cost-effective solutions.
[torbakhopper via CC License 2.0]