Hot and Humid

[Amooti]

I have a 1917 Gibson A that's never given me any problems. We moved to Columbia, South Carolina last year and last month began to learn the real meaning of humidity. Even with air conditioning it felt wet in the house.

Around the same time my mandolin's tuning went off. The intonation is correct with the strings open, but when I fret a string the note comes out sharp.

Any ideas of what is going on and what I can do about it?

Thanks,

Amooti

[Strado Len]

Instrument tops swell in high humidity. This raises the action. Intonation can also be affected.

You have several options:

1. Try lowering the action (if you have an adjustable bridge) and see if this improves the intonation.

2. Move the bridge back slightly (about 1/16") toward the tailpiece. This will flatten the fretted notes. Use an electronic tuner to compare harmonic vs. fretted note at the 12th fret. They should be the same.

3. Get a dehumidifier and keep your house or music room at 45% humidity.

[Tom C]

<span style='color:brown'>I select door #2</span>
2. Move the bridge back slightly (about 1/16") toward the tailpiece. This will flatten the fretted notes. Use an electronic tuner to compare harmonic vs. fretted note at the 12th fret. They should be the same.

[Bob DeVellis]

I'm with Tom. Although I'm a big fan of humidity control, if you're going to be residing in the Carolinas permanently (well, more or less), then it makes sense to set the instrument up for the environment. Here in North Carolina, summer heat/humidity plus A/C usually get me in the "sweet spot" between 40% and 50% humidity with no further intervention. So, the instrument setup may actually have been optimized for too dry an environment. If the relativel humidity gets up towards 60% I'd try cutting it back, as mildew can proliferate at about 65%. Be prepared to crank in humidity in the winter if it falls much below 40%. Dryness will do much more harm than moisture. Even mildew, unpleasant and stubborn as it is, does less harm than extreme dryness can. These old instruments are really much happier for much longer when kept between 35% and 55% humidity.

[Amooti]

Thanks guys. Still sweating, but my mandolin is in tune.

[kebmando]

important to note how dry the winters get when your running your AC on the East Coast. Dry air can be very hard on instruments, so certainy invest in either a case humidifer or a room humidifier for your instrument room.