October 1, 2001
Often we find that customers are concerned about the effects of cold temperature on their instruments. Actually, we should be concerned about the effects of low humidity. Particularly in the case of solid wood instruments, low humidity can cause severe changes to the instrument's playability as well as producing cracks in it's soundboard or back.
If you live in a cold weather region, you should be aware that the heating system in your home decreases the humidity in the air to an extremely low level. Instruments are usually constructed in an environment which maintains relative humidity levels near 45%. if you live in an area where you have freezing temperatures outside, the relative humidity inside your home may dip into the 20% range!
In the case of acoustic soundboards, the top sinks as the wood shrinks. This, in turn, produces lower action and you may notice that, suddenly, you begin to encounter buzzing when you play. As the humidity continues to fall, you may even find a crack in the delicate thin woods of your nice instrument. Changes in humidity can also affect the neck and fingerboard of any instrument, especially in the case of a maple neck or an ebony fingerboard.
In order to maintain a modest level of humidity, you must first determine the humidity in your home. Digital hygrometers are available for $25 - $50. While digital hygrometers are accurate to + or- 2%, the needle type are relatively inaccurate and can be off as much as 10%, depending upon the temperature.
If the air in your home is less than 40%, we recommend that you humidify the room where you keep your instrument. Keeping the temperature a little lower than normal will also help to elevate the relative humidity of the room. Room humidifiers are available at discount stores and home improvement centers in different sizes which range from about $70 to $130. Some humidifiers are now available with automatic controls which include the hygrometer. When temperatures are around zero degrees outdoors, the average size room may require three gallons or more per day in order to maintain 45% humidity at a temperature of 68 or 70 degrees inside. Although the size of the humidifier is most often stated according to the output per day, the capacity of the reservoir is usually more important in determining the size required. For instances, a particular 5 gal. humidifier may actually have a capacity for 2 gal. of water. If your room requires three and a half gallons of water on the coldest days of the year, you would still have to fill this particular humidifier twice each day.
If you find it impossible to humidify your living environment, an instrument humidifier is the next effective method of protecting your instrument. The clay type of humidifiers that are kept in the case pocket do little good. Choose one of the Dampit (brand name) style devices or the D'Addario Planet Waves system. The most effective Dampits also have a plastic sound hole cover. Be prudent, however, in the use of any instrument humidifier. Contrary to the marketing promises accompanying these devices, they do not release the precise amount of humidity into the instrument. They have no brain or working parts. They are simply sponges or phenolic foam that release as much water as you add to them. When the humidifier feels dry, it is performing no function at all. Conversely, we have seen instances where the excessive use of a humidifier has actually swollen an instrument apart! Not an exact science, but the instrument humidifier can be very helpful in the instance of a know humidity problem.
In summary, the best way to maintain your instrument is by the use of a room humidifier coupled with a digital gauge. Here are a few common sense habits that will also help during the dry months:
Keep the instrument in the case if you suspect humidity problems (sudden drops in the humidity can cause the most damage, and a good hard shell case will slow down the changes to the instrument's moisture level).