Humidity Control is of great concern in the colder months. Guitars are made out of wood, which will shrink and swell based on the relative humidity. When the seasons change and we turn on the heat, we change the environment around our instruments which can create problems over time if the change is not properly managed.
Guitars are best kept within a range of 45-55 percent relative humidity. This can be measured with a hygrometer. Some of the more ubiquitous Hygrometers among music retailers include the Oasis OH-2+ (which gets pretty good ratings and seems to work) and D’Addario’s PW-HTS (which gets poor ratings and seems to have accuracy issues). The Stretto Hygrometer is a more compact product that might have some variation here and there but seems reasonably accurate. The important thing is that you want a rough idea of where the relative humidity is so that you can take the necessary precautions to protect your instrument.
One of the most popular humidification products that is very affordable and easy to use is the Dampit. This is usually every young student’s first humidifier. Just run it under water, wipe off the excess moisture with a towel, and insert it into your instrument. If cellist Yo-Yo Ma likes it, it must be good!
Over time, the sponge inside the Dampit becomes less absorbent (most likely the result of calcium buildup and mineral deposits). A good way to extend the life of your Dampit is to use distilled water, but another, more “high-tech” variation on the Dampit concept is the Oasis OH-1 Soundhole Humidifier. Instead of a sponge, the OH-1 uses Humigel crystals which suspend the water in a gel that prevents damaging leaks but still allows for an effective, consistent supply of moisture for your instrument. The membrane that lines the humidifier allows water vapor to escape through the fabric but contains the liquid water. Replacement gels are available and distilled water is recommended.
The D’Addario PW-HPK-01 is a maintenance-free, two-way humidification system that automatically maintains the optimal relative humidity level within your instrument case. The product uses Boveda’s patented technology in a system that includes three “Humidipaks” and a soft mesh pouch that will not harm your instrument’s finish. The packets last between two and six months. Once they become firm, they should be discarded. Replacements are available in the PW-HPRP-03.
The emergence of a crack in your instrument can come as a bit of a shock. All of the practice time that you have invested produces an emotional attachment that can inspire a feeling of personal injury when the guitar experiences a trauma. Don’t neglect these preventative measures! Invest in some humidity control products and preserve the life of your instruments for as long as possible!