Before I moved to North Carolina I got rid of the cabinet I had modified to keep my guitars humidified during New England winters. I sold many instruments to prepare for the move and now have fewer that would need humidification. And, North Carolina — do I even need to worry about humidity down here.
The answer regarding local humidity is it depends. I checked weather history for the area from last year and discovered there wasn’t a single day during the winter months that the average humidity was lower than 40%. There are some caveats about that. First, there were some days when the lowest humidity was under 40%. Second, indoor humidity with heat might be less than outdoors when it is cold.
I discovered the real answer last week. The outdoor temperature has been under fifty degrees and the indoor humidity has been dropping. My digital hygrometers tell me the indoor humidity is now 29%. And I don’t have a humidified guitar cabinet anymore. What do I do now?
I could have watched, waited and hoped. How protective of your instruments do you need to be? Again, it depends on your tolerance for risk and the instruments. I have no problem leaving my inexpensive ukuleles out without humidification. But I’m not going to leave my classical guitar, Martin acoustic and Eastman jazz guitar out when the humidity falls. Still, although 40 to 50% Relative Humidity (RH) is ideal, short exposures to lower humidities shouldn’t be a problem. Not a problem but still a risk. Long term exposure to dry conditions is a problem.
The next thing I could have done — and had done back when I was in New England — is humidify the area where the instruments are stored. I could have put a small humidifier in the room or even in a closet with the guitars. But, for now, I’ve done something else which I’ve recommended before.
I purchased the D’Addario Humidipak humidification system. The system consists of three bags of a salt solution sealed in bags that let air in and out but prevent liquid from leaking out of the bags. Two of these are suspended in an outer bag between the guitar strings while the third is placed under the head of the guitar in its case. This system is alleged to keep the humidity between 40 and 50% when the case is closed and should last a minimum of two months.
Although D’Addario recommends replacement if the bags dry out, users have shared ways to extend the use of the paks. The first thing you could do is to include a more conventional humidification system in your guitar case such as an Oasis humidifier. The D’Addario system adds or removes humidity as needed while the Oasis only adds humidity. Using the two together during dry months allows the D’Addario system to last longer while insuring that the humidity isn’t too high. So far I haven’t done this but I will be watching to see if I should add additional humidification to my cases.
The second thing users have shared is how to restore a dried out Humidipak. It’s best to start this before the paks are too dry. The trick is to place the packs in a sealed container with a source of humidity. You don’t want to directly wet the humidipaks. For example, place the dry humidpaks in a zipper seal plastic bag along with a small bowl of water and seal them together. After a while, the humidipaks should be regenerated and ready to use again.
I don’t expect it to ever be as dry here in North Carolina as it was near Boston but I’m still going to protect my better instruments when the humidity drops much below 40% RH.
FYI – here’s the digital hygrometer I’m currently using to check on the indoor humidity. They’re inexpensive enough that I’ve got several of them.