Flu Season for Strings: Humidity & Your Instrument

As musicians we tend to practice indoors, often in air conditioning where humidity can be very low, typically anywhere from 10%-40%. On our way home, we may put our instrument on the back seat of the car where humidity can be further up in the 50-70%. Thinking our instrument is perfectly protected in its case, we then place it in our room where the cold winter air drops the humidity to below 30% putting stress on the timbers of our instrument and bows. With changes in conditions like this, the sound of a small ‘pop’ can signify major damage such as a bass bar or sound post crack.
While this is an extreme example, most instrument owners are less than certain about how to prevent damage caused by changes in humidity. Stringed instruments are made of wood, a material that expands when it absorbs moisture, and contracts when it dries. To further complicate matters, the two different types of wood used in building instruments—soft spruce for the top and harder maple for the back and sides—expand and contract at different rates. In extreme cases these changes can cause extensive damage requiring expensive repairs and are sometimes irrepairable. They can also cause the edges or seams to open, a much easier and less expensive repair.
The seams of stringed instruments are designed to open when needed. The edges are sealed with hyde glue that releases, or opens up, under climatic pressure. Other stronger glues won’t allow for this kind of “safety valve,” and the instrument (especially the top) routinely will crack. As a result, older instruments with many repaired cracks tend to suffer even more injury from climate changes.
Ideally, a stringed instrument should always be kept in a moderate environment with 50 percent humidity. A few of us are fortunate enough to live in a region with these constant conditions, but most of us do not. In Queensland, for example, our Winters are very dry and many have heated homes driving the humidity down to 10 or 15 percent—and the summers are often hot and humid. If you live in more central areas where it’s hot and dry a good deal of the time, you need to take extra measures to stabilise the conditions inside the instrument case. In addition to physical damage, stringed instruments suffer tonally from humidity changes. A dry climate will often cause the tone to become hard, edgy, and dry. Conversely, excess humidity causes instruments to sound dull, thick, and unresponsive.
So how do you maintain the correct temperature and humidity around your instrument? The two basic approaches to consider are managing the humidity within the instrument itself and addressing the climate in the instrument’s storage area, that is, in the case. There are many commercial products available
Instrumental Devices:
Some players prefer to use a humidifier that goes in the instrument rather than in the case; others decry this practice, fearing that it could expose the wood to direct contact with water. The best-known product of this type is the Dampit and are relatively inexpensive. The concept is simple: The Dampit is a flexible, perforated green tube with a sponge inside it. After moistening the sponge, you insert the Dampit into one of the f-holes and leave it in the instrument when you’re not playing it. When the sponge inside the Dampit dries out, you simply remoisten it. The drier the climate, the more frequently you need to check the moisture level (in very dry conditions, two Dampits may be needed one in each f-hole).
However, violin makers and dealers and players are split in their acceptance of this type of product. Some say you need to check the Dampit diligently in very dry climates to make sure it is consistently moist. And some claim that the Dampit itself can damage an instrument by introducing too much moisture into the instrument’s environment. Despite the differing opinions between makers and dealers, most musicians accept this product due to its simplicity.
In the Case:
If you want to control the climate in the case, you have several ways to go. A good place to start is to look for a padded case cover, much like the ones used by Bobelock or the 3 layer foam interiors of BAM.  These bags and cases offer insulation to protect against both hot and cold weather and have amel-female seal to minimize environmental fluctuations.
You might also consider adding a hygrometer and a humidifier to your case. A hygrometer measures the level of humidity, while a humidifier can correct dryness. An in-case humidifier often comes in the form of a small tube filled with water-saturated material that releases moisture at a controlled rate.
Many violin and viola cases include a built-in hygrometer and a vaporizer bottle however many cheaper model cases often have an “hygrometer” which is only for decorative purposes and is often best to check with your string specialist.
A more elaborate and reportedly efficient in-case approach is the dual system produced by Planet Waves. The Humidity and Termperature Sensor monitors climate within the case. The Instrument Humidifier can then be moistened as needed to maintain the appropriate humidity level without risk of direct moisture contact with the instrument’s body.
Take Care
In our shop, we regularly see instruments damaged by extremes of temperature and humidity, which is sad because it is often preventable damage. More often than not, the repair costs are high because the damage is so extensive. You should be ever mindful of the conditions around you and remember stringed instruments are fragile, so protect your investment.

Play It Safe
Even if you use one of the humidification systems mentioned in this article, you should take additional steps to protect your violin, viola, cello, or double bass. I strongly recommend the following:
•    Avoid extremes in temperature or humidity.
•    Never leave your instrument in a closed car. Besides the possibility of theft, on a hot, sunny day the temperature in the passenger compartment can quickly rise to 50°C or more.
•    Never put your instrument in the trunk of your car, especially when it is hot or cold.
•    Don’t store your instrument near a heater or air conditioner.
•    Unless your home is well insulated, don’t store your instrument near an outside wall.

•    Do not leave your instrument in prolonged exposure to the Sun, even if inside a case

•    Wrap your instrument in a natural silk cloth or scarf. The natural fibre helps to slow down sudden changes in temperature and humidity to limit stress to timber