Humidity

[BenE]

I recently got a digital hygrometer/temperature gauge and have been watching it over the last week. I live in Arkansas and this time of year it is sort of like a big swamp! The humidity level has been running between about 65% up to about 73%. I don’t think that can be too good for the mandolin. I thought about putting some of those desiccant packs in my case with the mandolin but then I started thinking that it is probably the drastic changes of humidity that affect the mandolin more than anything else. So if I get my mandolin in its case at the 50% humidity level and take it out to play in an 80% humidity environment I may be hurting it more in the long run. What to do? What do you guys suggest? I’m sure some of you southerners have run into the same problem. Any suggestions?

[Luthier]

The main concern will be to be very careful in the winter when the humidity is low. #Wood has the property to expand and contract. #Assuming your mandolin #1. was built well with seasoned wood and #2. gluing was done in a relatively low humid environment, you should be ok. #The big problems arise when people fail to keep a source of moisture around the instrument in the dry winter months. #This is when the wood contracts and has the tendency to split. #The glue joints don't let go but the wood will. #Instruments sound "mushy" in humid weather and sound "brighter" in the dryer months of the winter. #This is due to moisture content. Just be aware when the humidity goes away. #I don't glue anything unless I can do it at a low humidity level and I make sure all the wood has been sitting in the same room being "conditioned" at the same time. I try to keep things between 30 to 50%

Whatever you do.....Keep it out of hot vehicle and out of the sun or you won't have to worry about the humidity at all

Don

[John Flynn]

The dessicant packs will work. I would try one at a time until you get the humidity down to where you want it. There are also renewable dessicant devices out there if you want to go that route. Personally, I doubt the resulting humidity changes would be "drastic." My experience is that taking a mando out of a case that was at say, 50% humidity into a room that is higher or lower by up to 15% doesn't seem to cause the instrument to go out of tune, which is what I would expect to see. Unlike the effects of temperature changes, my impression is that the effects of humidity changes are very gradual. But I admit, I am no expert, just a mando player who has read up on this issue and messed around with it quite a bit.

[Chris Burt]

I've built and repaired instruments for years. As Don implied, humidity lower than that in which the instument was built is the real problem. Recently, a client of a well-known classical guitar maker recently sent his relatively new guitar back to the maker. The guitarist spent several months in a _very_ dry environment and didn't use the Dampit that came with the guitar. The guitarist had also failed to read the literature on humidty that came with the guitar. Needless to say, the lovely instrument had some serious cracks and the guitarist felt that the instument's construction was flawed. The luthier was horrified at the treatment the guitar had received, but fixed the guitar to build good will. Not that this luthier really needs the good will.

That said, I'm sure that luthiers in Hawaii could supply us with horror stories of glue failure in hot, humid environments.

Also, going suddenly from extremely cold to extremely hot and dry can be a big problem. This condition can happen, as it did to me, in the winter when the instrument, in its case, is left in an unheated car for hours and then brought indoors. In such a situation, let the cold instument warm in its case very, very slowly before opening the case.