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cml
01-26-2016, 05:40 AM
Hello everyone!

I know this is a much discussed topic, butI have a few question that I have so far been unable to find answers for and I am sure the community here knows the answers.

After reading article upon article on ukulele/guitar care, they all mention to keep the instrument at a good relative humidity level, say 45%.
This is often followed by statements such as, "changes in humidity is bad for your guitar/ukulele, especially to lower values" and "rapid changes in humidity and temperature is bad".
It's not hard to understand this, dry air "sucks" the water content of the wood out of instruments while trying to equalize humidity levels.

But this leads me to my question, how much of a "rapid" change is bad? Say the humidity level drops from 45% to 35% during the night, but then goes back up to 45% during the day? Is such an occurence enough to damage an ukulele, even if it happens sporadically?
How long does it take for the wood to dry out (lets use koa as a reference)?

Next question (last :)) concerns hygrometers. Any ideas as to why two digital hygrometers would show a difference of 4% during a calibration test (salt test of 75%, hygrometer 1: 72%, hygrometer 2: 76%), but upon going back down to normal levels they are now displaying a disrepancy of 12% (hygrometer 1: 45%, hygrometer 2: 57%)?

Thanks for your time and help!

Rllink
01-26-2016, 07:11 AM
That is a good question, and I've wondered it myself. I often think about the wood, and how it really relates to our need to quantify everything in our lives.

mikelz777
01-26-2016, 07:37 AM
Founded or unfounded, there seems to be any number of opinions out there that will either calm you or scare the heck out of you for concern of your ukulele's well being. I think that a rapid change in temperature is of more concern than a rapid change in humidity. When I open my uke case, I'll typically get humidity readings of 45-50% - perfect right? I then happened to leave the hygrometer out of the case and was playing my uke for an hour and a half. When I put my uke back in the case, I noticed the hygrometer was reading the room humidity at 29% - uh oh, we were in the danger zone that whole time! This happens regularly in the winter months and my ukes have not suffered at all as a result. I think it's prolonged exposure to too low or too high humidity where you risk possible issues. If the uke is exposed to a couple of hours outside the desired humidity levels then I wouldn't be concerned but if it's a day or days, then I'd start getting concerned. When I'm not playing them, my ukes are always in their hard cases with a humidifier during the cold, dry months.

As far as the hygrometers go, they can be hinky. I just keep in mind that they are meant to measure relative humidity and that they may be a bit off from actual. I have 2 hygrometers and one consistently measured 4% lower than the other measuring room humidity. One was more accurate with the salt test (75% vs. 73%) so I put a sticker on the back of the other reminding me to add 4 to the percentage of humidity that it was reporting.

RichM
01-26-2016, 07:55 AM
. I think it's prolonged exposure to too low or too high humidity where you risk possible issues. If the uke is exposed to a couple of hours outside the desired humidity levels then I wouldn't be concerned but if it's a day or days, then I'd start getting concerned.

Yes, exactly. Sometimes I hear people talk like exposing their instrument to low humidity for an instant will automatically cause it to crack. That's pretty unlikely. Will leaving your uke in low humidity for weeks affect playability or even cause cracks? Maybe, maybe not. But there is clear evidence that you are increasing the risk. Why do that when it take a few pennies' worth of water and about ten minutes out of your week to protect it?

cml
01-26-2016, 08:09 AM
Oh, I dont worry about short intervals like a couple of hours of playing, I am just thinking of keeping them accessable on the wall rather than in their cases which is how I store them atm (with a humidifer in the sound hole, and one under the neck) I humidify my whole house and its pretty stable at 40-45%, but can sometimes dip down to 35% if I forget to refill the humidifier. That was what got me thinking, there's all this info out there that low humidity is bad, but nothing on how quickly it can be dangerous to your ukes.

DownUpDave
01-27-2016, 02:06 AM
Oh, I dont worry about short intervals like a couple of hours of playing, I am just thinking of keeping them accessable on the wall rather than in their cases which is how I store them atm (with a humidifer in the sound hole, and one under the neck) I humidify my whole house and its pretty stable at 40-45%, but can sometimes dip down to 35% if I forget to refill the humidifier. That was what got me thinking, there's all this info out there that low humidity is bad, but nothing on how quickly it can be dangerous to your ukes.

If your main concern is the humidity being at 45% then dipping to 35% you should have nothing to worry about. As far as guide lines regarding how fast a drop is bad I have never read any kind of documentation on it. Common sense would suggest it is a prolonged exposure to low humidity, say 10%, that would cause wood to lose its moisture content. From 45% to 35% back up to 45% is nothing really.

coolkayaker1
01-27-2016, 02:41 AM
87793I bought, literally, six of those digital hygrometers from Amazon--their bestselling ones that go for ten bucks each--all at once. I set them next to one another on my kitchen table and watched them for a few days. They were all over the place. Some reading as much as nine points different than the others.

Solution: I took the mathematical average of them all, then applied stickers to each to remind me how far off they were from that average for a quick mental adjustment every time I look at them. One might say "+2" and another might have a sticker "-5", that sort of thing. One of the six devices came in at the mathematical average, and that one I love as dearly as a pet.

Why buy six? To put them in my see-through humidor condo. Lol. 87792

mm stan
01-27-2016, 02:46 AM
I do believe every type of wood, and every individual kind of wood has different strength and durability.
Even wood from the same tree but different parts of the tree and weak spots of different areas may differ.
There is no way of figuring out just by temperature changes, humifity as there unknown variables also
To be considered.
In hawaii we have no issues in that area
But wood shrinkage or changes can cause cracks, as the braces or glued sides hold certain areas stable while changes happen.
Which is one way of cracking.

Rllink
01-27-2016, 03:01 AM
I'm just a skeptical person in general, and I'm not what one would call a gentle and cautious person when it comes to things like ukuleles. I've found both my ukuleles to be pretty rugged. In fact, I'm always surprised how much they can take. Two things though, I do keep them in hard cases. It is not so difficult for me to take them out and put them back in, and it doesn't seem to hinder me from playing them. But also, it isn't hard to stick an oasis humidifier in there when I put them back, it is no effort at all, so why take the chance?

But one note, I do have a violin that belonged to my grandfather, and he brought it back from Europe after WWI. The neck is coming loose, and I took it in recently to have it looked at. They told me that it had dried out, and the glue wasn't holding anymore. So it can happen. Of course, My grandpa played it for years after the war, my mother played it in school, and it has been sitting in my basement for thirty years. But it can happen.

Pukulele Pete
01-27-2016, 03:07 AM
I have a guitar , I've owned it for an easy 35 years , it is well over 100 years old , has never been humidified , it has no cracks . I live in the Northeast , humidity goes way up and way down. Just sayin'.

cml
01-27-2016, 03:13 AM
Many thanks for all the interesting replies, seems I was right in that this great community would engage themselves to try and sort out this mystery :).


If your main concern is the humidity being at 45% then dipping to 35% you should have nothing to worry about. As far as guide lines regarding how fast a drop is bad I have never read any kind of documentation on it. Common sense would suggest it is a prolonged exposure to low humidity, say 10%, that would cause wood to lose its moisture content. From 45% to 35% back up to 45% is nothing really.Thanks, this is really helpeful Dave. I was already keeping my house at around 40-45% rel humidity (or was trying to) as I have parrots, and they dont like the dry winters of Sweden. On the part of there not being any documentation out there on the humidity/time-function, I am suprised, but as I wrote in my OP, I couldnt find anything on it either - and I really tried.
Hopefully we can gather some information in this thread that can be helpful for newer players (and perhaps long time ones as well).


87793I bought, literally, six of those digital hygrometers from Amazon--their bestselling ones that go for ten bucks each--all at once. I set them next to one another on my kitchen table and watched them for a few days. They were all over the place. Some reading as much as nine points different than the others.

Solution: I took the mathematical average of them all, then applied stickers to each to remind me how far off they were from that average for a quick mental adjustment every time I look at them. One might say "+2" and another might have a sticker "-5", that sort of thing. One of the six devices came in at the mathematical average, and that one I love as dearly as a pet.

Why buy six? To put them in my see-through humidor condo. Lol. 87792
:) Did you do the salt test? Otherwise you might want to try that, with all six in the same air tight containter. You might already know this, but the salt test creates an environment where the relative humidity is spot on 75%, so you can see how much the hygrometers differ. Hopefully that can help you and see if your average is right :).
See here for more info, cigar people seem to know their way around this stuff:
https://www.neptunecigar.com/tips/how-to-calibrate-your-hygrometer

EDIT: Going to take my own advice and re-do the salt test. This time they are tested together, they were tested individually before. I'll let you know how it goes tomorrow.

Cheers!

bedweazel
01-27-2016, 07:01 AM
Thanks for this thread. I've had the same questions. I hang mine on the wall in my home as well. Humidity was in the 40-45% range because we had a very mild Fall/early-Winter. That has since changed. Now that the heat has been running daily the humidity hasn't gone below 30%. I realize that is at the lower end of the acceptable range. No issues though.

I was wasn't sure about temperature changes since we have a programmable thermostat that swings by 5 degrees depending on time of day. Doesn't seem like enough to be an issue.

RichM
01-27-2016, 08:27 AM
I have a guitar , I've owned it for an easy 35 years , it is well over 100 years old , has never been humidified , it has no cracks . I live in the Northeast , humidity goes way up and way down. Just sayin'.

Sure, what could go wrong?

http://www.fretnotguitarrepair.com/images/cracks/pickguard-crack-lg.jpghttp://cdn2.hubspot.net/hub/458203/file-2487031304-jpg/IANS_FOLDER/IMG_0098-300x225.jpghttps://richboromusic.files.wordpress.com/2013/04/img_0144.jpg

Rllink
01-27-2016, 08:36 AM
So was it low humidity that caused that, or could it have been something else?

cml
01-27-2016, 09:17 AM
This is turning out to be a really interesting thread!

I think Rich's guitar? likely cracked of low humidity, but the question remains, how long did it take to get the wood to a state where damage was done?
How long does it take at humidity drops (and how big do they need to be) for bowing, sharp frets or even cracks to develop?
This is likely a function of how big humidity drop is (relative humidity is dependant on temperature), time and wood properties, but it should be possible to estimate on softer woods, medium hard woods and hardwoods for someone with the knowledge (not me obviously :))

Maybe someone from the luthier's forum can chime in?

RichM
01-27-2016, 09:18 AM
So was it low humidity that caused that, or could it have been something else?

I just trolled the internet for photos of humidity cracks. But they are real, they do happen, and no, they aren't inevitable.

Down Up Dick
01-27-2016, 10:23 AM
So, if a Uke cracks is it still playable? Can one still make passable music on it? :old:

mikelz777
01-27-2016, 10:24 AM
The bottom line and what we need to keep in mind is if an instrument is not properly humidified, it doesn't necessarily mean that the instrument will be damaged but it significantly increases the odds that it could result in damage. Trying to establish the parameters of how long you can push the boundaries before suffering possible damage is kind of like asking how many times can one have unprotected sex before impregnating someone or catching a STD. It might happen the first time you push it or it may not happen for weeks, months, years or ever.

I had an all laminate uke which I never humidified because I didn't think a laminate needed it. It happened to be winter and dry when I was really noticing how sharp the fret edges seemed when I hadn't really noticed it before. I started to humidify it and not only did that cure the sharp fret edge issue, it changed the sound of the uke (for the better) as well. Humidity made a noticeable difference even on an all laminate uke!

If you are questioning your situation, you may not have anything to worry about but I'd advise erring on the side of caution. There's little consolation when the damage is done and there was likely something you could have done about it.

Pukulele Pete
01-27-2016, 10:54 AM
So, if a Uke cracks is it still playable? Can one still make passable music on it? :old:

Absolutely , I have a 30's Martin that had a bunch of cracks . I repaired them and it sounds great. I just got a late 20's Style 2 that has 4 cracks that I'll fix soon
and it will be fine too .

Inksplosive AL
01-27-2016, 11:09 AM
So, if a Uke cracks is it still playable? Can one still make passable music on it? :old:

I have two ukuleles both from Vietnam made of air dried wood. The tenor cracked on top under the bridge in a dark stripe of the acacia wood from the gas heat in my house the first winter I had it. I rehumidified it and after asking questions in the proper area of the forum I simply used a percussive method to apply some tightbond and let it dry clamped. I started a small crack in the back with the clamp. Both cracks have been stable for over a year now and if I play all my ukuleles one after another this tenor sings much like the koahola concert I have. I just dislike tenor string tension and have been thinking about alternate tunings.

I have soprano which I noticed after realizing the ukulele had not had a spin in the humidity box all summer has cracked in a dark area on the walnut on top. It seems stable and is almost unnoticeable, the ukulele in question is just very quiet.

I have seen pictures of Pono monkey pod ukuleles cracked in darker areas on the wood so I'm becoming a believer that while pretty these woods are possibly more susceptible in these areas. So long way round to answer this question certainly a better musician could make very beautiful music with both.

On topic... I haven't seen immediate change in anything overnight but when things change it happens pretty fast.

coolkayaker1
01-27-2016, 11:16 AM
:) Did you do the salt test? Otherwise you might want to try that, with all six in the same air tight containter. You might already know this, but the salt test creates an environment where the relative humidity is spot on 75%, so you can see how much the hygrometers differ. Hopefully that can help you and see if your average is right :).
See here for more info, cigar people seem to know their way around this stuff:
https://www.neptunecigar.com/tips/how-to-calibrate-your-hygrometer

EDIT: Going to take my own advice and re-do the salt test. This time they are tested together, they were tested individually before. I'll let you know how it goes tomorrow.

Cheers!

I'm familiar with the salt test but don't see how it would help me as (a) these electronic humidity gauges are not adjustable like the analog models, and (b) I can already see the differences in each hygrometer in the real-world setting in which they would exclusively be used. Please help me understand as I might well be missing something. Thanks for any advice.

cml
01-28-2016, 01:41 AM
I'm familiar with the salt test but don't see how it would help me as (a) these electronic humidity gauges are not adjustable like the analog models, and (b) I can already see the differences in each hygrometer in the real-world setting in which they would exclusively be used. Please help me understand as I might well be missing something. Thanks for any advice.
I'll be glad to help!
Yes, you are missing one thing, and that is that you do not have a set point where you are SURE of the humidity. Therefore all your + and - are based on what the hygrometers show at a unknown humidity. Granted, you have six of them so probability dictates that you shouldnt be too far off with your average.

However, if you do the salt test then you KNOW that the humidity in the cointainer is 75%, and you can write notes accordingly, like -5% for example. The salt test works just as well with digital hygrometers as analog, but sometimes you cant adjust a digital one and then you have to write down the difference instead.

Regarding my own test, I redid it in a better sealed container with both hygrometers, the difference between them was now 8% (68% and 76%), which is more like the normal 5-10% difference I see. Any other differences is then because of tolerances, in my case, it's +/-2% on both hygrometers. So now I know, that my hygrometers are accurate at X+7% (+/-2%) and Y-1% (+/-2%). Makes sense?

cml
01-28-2016, 01:52 AM
The bottom line and what we need to keep in mind is if an instrument is not properly humidified, it doesn't necessarily mean that the instrument will be damaged but it significantly increases the odds that it could result in damage. Trying to establish the parameters of how long you can push the boundaries before suffering possible damage is kind of like asking how many times can one have unprotected sex before impregnating someone or catching a STD. It might happen the first time you push it or it may not happen for weeks, months, years or ever.

I had an all laminate uke which I never humidified because I didn't think a laminate needed it. It happened to be winter and dry when I was really noticing how sharp the fret edges seemed when I hadn't really noticed it before. I started to humidify it and not only did that cure the sharp fret edge issue, it changed the sound of the uke (for the better) as well. Humidity made a noticeable difference even on an all laminate uke!

If you are questioning your situation, you may not have anything to worry about but I'd advise erring on the side of caution. There's little consolation when the damage is done and there was likely something you could have done about it.
No, I dont think you are making a fair comparison here.
Humidity is a much discussed topic in the musical instrument world, and I am VERY suprised to see that noone seems to know how quickly this is a problem. There does seem to be more like me who wonder though, judging from this thread.

Take for example that a lot of manufacturers say that warranty is void if you subject your uke or guitar to low humidity. This is really fuzzy, and to be able to make that hold up, then they need to specify what that is, and which circumstances that will void the warranty. Say for example a 10% drop under the reccommended 45% for 5 days. Now we are getting somewhere, right?
I googled some more and actually found a really good example of someone who DOES specify this. This is not intended in anyway as me advertising them (never heard of them before this), but their warranty page discuss this topic in detail. http://saliguitars.com/moisture_meterNEW.htm

This isnt about me wanting to risk my ukes, far from it. I'll be sure to keep them in their cases should my indoor relative humidity drop below 40%. I do however feel that it is very strange that everyone seems content with not knowing the factors which governs damage to their instrument. Personally, my curiousity and pursuit to learn new things tells me otherwise. I've already learned a lot from this thread, and I hope to learn more :)!

coolkayaker1
01-28-2016, 05:06 AM
I'll be glad to help!
Yes, you are missing one thing, and that is that you do not have a set point where you are SURE of the humidity. Therefore all your + and - are based on what the hygrometers show at a unknown humidity. Granted, you have six of them so probability dictates that you shouldnt be too far off with your average.

However, if you do the salt test then you KNOW that the humidity in the cointainer is 75%, and you can write notes accordingly, like -5% for example. The salt test works just as well with digital hygrometers as analog, but sometimes you cant adjust a digital one and then you have to write down the difference instead.

Regarding my own test, I redid it in a better sealed container with both hygrometers, the difference between them was now 8% (67% and 76%), which is more like the normal 5-10% difference I see. Any other differences is then because of tolerances, in my case, it's +/-2% on both hygrometers. So now I know, that my hygrometers are accurate at X+7% (+/-2%) and Y-1% (+/-2%). Makes sense?

Thanks for the input. It makes sense, but only sort of. Why? If I use the hygrometers at humidities other than 75% on a daily basis, and I have recorded each over typical humidities in my home over several days, it seems like any "real world" differences in practical use would have been well accounted for, no? Another way of looking at it: if two hygrometers were precisely 7% off at the precise 75% salt-tested, "lab" values, but in the family room where I store the ukes they are 5% different from one another on average, wouldn't I want to label them as 5 points different rather than 7? (Someone will now chime in "who cares", so I'll write it here to save them the trouble. Lol). Thanks, Cml for your good input. I think adjustable analog humidifiers are well worth the salt test so that they can be adjusted, no question. Thanks again, Cml and all.

cml
01-29-2016, 04:24 AM
Another way of looking at it: if two hygrometers were precisely 7% off at the precise 75% salt-tested, "lab" values, but in the family room where I store the ukes they are 5% different from one another on average, wouldn't I want to label them as 5 points different rather than 7?

Because you dont know how much they really differ, most hygrometers have a tolerance to take into account. But as you have six(!) of them, your mathematical average is likely good and you are probably close to the real value anyway :).

blodzoom
01-29-2016, 06:41 AM
Thanks for the input. It makes sense, but only sort of. Why? If I use the hygrometers at humidities other than 75% on a daily basis, and I have recorded each over typical humidities in my home over several days, it seems like any "real world" differences in practical use would have been well accounted for, no? Another way of looking at it: if two hygrometers were precisely 7% off at the precise 75% salt-tested, "lab" values, but in the family room where I store the ukes they are 5% different from one another on average, wouldn't I want to label them as 5 points different rather than 7? (Someone will now chime in "who cares", so I'll write it here to save them the trouble. Lol). Thanks, Cml for your good input. I think adjustable analog humidifiers are well worth the salt test so that they can be adjusted, no question. Thanks again, Cml and all.

The point of the test is to find out how far each one is from "True". Theoretically, your hygrometers could all be 20%+ off. Why does it matter if you know that they're 5% different from each other when you don't know what the actual humidity is. Having 6 of them, I would assume, gets you in the ballpark, but you don't know anything for sure.

Still Water Weapons
01-29-2016, 11:12 AM
The point of the test is to find out how far each one is from "True". Theoretically, your hygrometers could all be 20%+ off. Why does it matter if you know that they're 5% different from each other when you don't know what the actual humidity is. Having 6 of them, I would assume, gets you in the ballpark, but you don't know anything for sure.

This is the difference between precision and accuracy.


So, my .02 on the original point. It would be impossible to say, x number of days at Y% humidity will damage an instrument, or even, Z% change in RH at Q degress Fahrenheit would cause damage. There are wayyyyy too many variables to make a definitive statement like that. I'm sure we can all guess at the long list of variables. The other side of that coin is it's very difficult from the manufacturer's point of view to quantify those numbers for warranty issues. "Well, we feel the humidity was too low"... Consumer "Well, it's been at that humidity for 11 years"...
And if a Uke is stable at 22% for several years and then a new owner says "I need to keep my new uke at the proper RH" and puts it in his new cabinet at 45% it could also damage the instrument. (Presumably), I'm no expert, but I did stay at a Holiday Inn and I have worked with wood for many years. I think I may have even confused myself. :D