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View Full Version : Relative humidity and effects on fretted instruments



mcnut
11-12-2011, 06:01 PM
This can give one concern if you like to keep your uku out hanging on the wall like I do.

Ran across an article on Anglefire.com talking about keeping the right level of humidity in guitar stores. They pointed out these affects on instruments at decreasing humidity levels:

Typical effects of humidity changes on guitars.
@ 50% R.H. All guitars in store are in good condition.

@ 40% R.H. Some guitars (electric and acoustic) begin to get sharp fret ends.

@ 35% R.H. Tops begin to shrink, fret ends protrude more, brand new guitars (instruments just arriving in the store) do not show these symptoms since they have not been exposed. These guitars look and feel better than stock that is even a month old.

@ 30% R.H. A guitar or two may crack, but even those that are not cracked have lost about an ounce of water and the tops are sunken. Usually a higher saddle is necessary to make the guitar playable.

@25% R.H. More guitars crack. A lot of fret filing is needed. You begin to call the manufacturers to report that you have guitars with problems.

The article pointed out that if you take 40 degree outside air at 50% humidity and bring it inside and warm it to 70 degrees the relative humidity drops 15%. It also pointed out that an instrument store may pump 40 to 60 gallons of water a day into the air to keep the store at the proper level for the instruments.

This morning in Atlanta we 44 degree air and 58% humidity, and inside I was carrying 23% humidity at around 70 degrees. May have to reconsider keeping the herd out of their cases.

Then in comes the health squad to tell us that at 50% humidity we are creating a breeding ground from mold. Man and instruments may not be meant to cohabitate.

coriandre
11-12-2011, 06:09 PM
A small humidifier in a case works very well...

mds725
11-12-2011, 06:13 PM
I keep my really humid relatives away from my ukes.

To address your cohabitation point, that's why I keep my ukes in their cases with a case humidifier when I'm not playing them. That way, we all get the humidity we want.

Trinimon
11-12-2011, 06:18 PM
Good to know the average RH wooden instruments starts to go south. I have a hygrometer on my coffee table. When I see it start to hit 50% RH, I make sure the humidifiers are charged. Mind you, I only have two solid wood ukes to worry about. For the peeps with the 10+ ukes, it might be a chore. :p

mm stan
11-12-2011, 06:20 PM
Just wondering if the weather affects the strings too....hmmmmm

consitter
11-12-2011, 09:08 PM
Just wondering if the weather affects the strings too....hmmmmm

Sure does mine. Noticed that this morning when I pulled her our of the case to play. G was way out of whack. Others were pretty good though.

beginnerukeman143
11-12-2011, 09:33 PM
i live in Guam an Island in the pacific so its humid all year around....... and i mostly play my uke outside, so it gets alot of good humidity whenever i dont play it, i usually leave it on the wall in the back of my house (where i usually turn the AC off so the air is not dry at all)

Markr1
11-13-2011, 05:00 AM
I was just wondering after reading this thread. I keep my acoustic guitars and ukes in cases with humidifiers but don't keep my electric solid body guitars in cases they hang on the wall all the time. Do I need to keep them in a case during winter too? I'm not to worried about the bodies but I was reading about the fret ends on the neck and I guess that could happen to an electrics neck to but don't know. During the deep of winter here in Kentucky my room humidity gets down to 25%.

Tor
11-13-2011, 10:36 PM
If the relative humidity is low for long enough then the fretboard will shrink. You'll notice because the fret ends may start to stick out (try moving your hand up the neck and check how it feels).

Last winter I visited a small one-man music shop and the owner was working with a file on the frets of a strat. Told me he had to do this for all of the instruments due to the low local humidity in the winter season (not in his shop, because he was using a humidifier, but his customers didn't).

As it's a one-man shop he actually did the work out in the shop, that's why I got to see it.

-Tor

kenikas
11-15-2011, 03:40 PM
Good to know the average RH wooden instruments starts to go south. I have a hygrometer on my coffee table. When I see it start to hit 50% RH, I make sure the humidifiers are charged. Mind you, I only have two solid wood ukes to worry about. For the peeps with the 10+ ukes, it might be a chore. :p
I can assure you it can be! Usually a labor of love, but up here in the high desert a necessary one.

Plainsong
11-15-2011, 03:49 PM
My two main ukes are in their cases with humidifiers, and one for each seems plenty. I've also got a room humidifier that is now pressed into service now that the heater is on all the time and it's getting to winter. Once the humidifier cuts off, the RH can drop quickly to 30%. As winter continues, it'll be 15% or so if I wasn't running a humidifier. I have the Ohana and Sailor Brand out, but the uke rack is close to the humidifier... not crazy close, but they're nextdoor neighbors. I figure even when the humidifier struggles to get to 30% in here, they're close enough for jazz. No reason to get too crazy about it, but time will tell.

I like to room humidify as well so that it's not such a huge swing when they come out of the case. I remember from my clarinet days, reactions to too much or too little humidity were rather immediate (not that they instantly break of course, but the response of the wood is quick).

Then come June, I can finally shut down the humidifier and bring all the ukes out, but for now, the babies sleep in their cases, and the workers should be close enough.

Rick Turner
11-15-2011, 04:12 PM
Just remember that we makers consider it YOUR responsibility to keep wood instruments properly humidified. We cannot build real wood instruments to withstand extremes of heat, dry, or humidity, and if those are your conditions and you just don't want to take care of the instruments, then you should consider plywood or carbon fiber ukes.

I recently got one of my Compass Rose tenors back with the bridge coming up and the top distorted. There were thin threads of glue evident between the bridge and the top. The only way that happens is if the instrument gets to above about 135 degrees F. I gently asked the owner if the uke had gotten over-heated...and it turned out that it had been in a trailer in the sun in Southern California for a couple of days. OK, happy to fix it, but it's not warranty work...

I'm tempted to build in heat monitor strips...these little patches that change color when they hit a pre-determined temperature. They're not terribly expensive, and they do tell tales...

Rick Turner
11-15-2011, 04:21 PM
http://www.tempil.com/products/tempilabel/tempilabel-series-4/

Dan Uke
11-15-2011, 05:06 PM
Wow!!! Above 135 degrees!! Someone spends that kind of money and doesn't take care of their instrument...maybe money grows on trees for them


Just remember that we makers consider it YOUR responsibility to keep wood instruments properly humidified. We cannot build real wood instruments to withstand extremes of heat, dry, or humidity, and if those are your conditions and you just don't want to take care of the instruments, then you should consider plywood or carbon fiber ukes.

I recently got one of my Compass Rose tenors back with the bridge coming up and the top distorted. There were thin threads of glue evident between the bridge and the top. The only way that happens is if the instrument gets to above about 135 degrees F. I gently asked the owner if the uke had gotten over-heated...and it turned out that it had been in a trailer in the sun in Southern California for a couple of days. OK, happy to fix it, but it's not warranty work...

I'm tempted to build in heat monitor strips...these little patches that change color when they hit a pre-determined temperature. They're not terribly expensive, and they do tell tales...

Plainsong
11-16-2011, 12:22 AM
Bake uke for 3 days at 135F, or until a crispy bubbly golden brown.

Oh the humanity!


Just remember that we makers consider it YOUR responsibility to keep wood instruments properly humidified. We cannot build real wood instruments to withstand extremes of heat, dry, or humidity, and if those are your conditions and you just don't want to take care of the instruments, then you should consider plywood or carbon fiber ukes.

I recently got one of my Compass Rose tenors back with the bridge coming up and the top distorted. There were thin threads of glue evident between the bridge and the top. The only way that happens is if the instrument gets to above about 135 degrees F. I gently asked the owner if the uke had gotten over-heated...and it turned out that it had been in a trailer in the sun in Southern California for a couple of days. OK, happy to fix it, but it's not warranty work...

I'm tempted to build in heat monitor strips...these little patches that change color when they hit a pre-determined temperature. They're not terribly expensive, and they do tell tales...