Not another humidity thread... but, really...

[DesolationAngel]

So, I have a question about humidity.

I humidify in the winter and currently dehumidify in the summer. I keep my guitars within a decent range of temperature and humidity but try not to obsess and stress over it.

Last winter had some brutal stretches. I heard from a number of sources that it caught them unawares and that guitars had cracked. I put all of my guitars in one room and cranked the humidifier on full blast... and just managed to sustain a decent level of humidity. But, at the same time, one of my guitars was in a case and in a public storage facility that isn't temperature or humidity controlled. It stayed out there for the whole winter. I checked on it a couple of times and it was a-ok; no warps, no cracks, nothing.

So, my question is... how come? It's a solid spruce topped jumbo with quilted maple back and sides. It was detuned and in a Hiscox case. Did I get lucky? Are those Hiscox cases really good? Is maple more resistant to cold/low humidity than other woods?

Just curious...

[ljguitar]

Originally Posted by DesolationAngel

…Did I get lucky? Are those Hiscox cases really good? Is maple more resistant to cold/low humidity than other woods?

Hi DA...

Hiscox cases are good for protection from nicks, dings, bangs, not a barrier against humidity changes. They are neither airtight nor moisture proof.

Yes, I'd say you got lucky, but that is a non-scientific opinion.

It's cheaper and easier to put them is storage, so if you are feeling lucky, you could just not humidify and see what happens this year…I have guitar playing friends who do that.

Thankfully good guitars are usually repairable if you have a good tech around.

[Misifus]

The first thirty-plus years that I owned good quality guitars, I never concerned myself about humidity. I bought my first good guitar (a Martin D-18) in 1964. Beyond not taking it to Panama, I didn't do a thing about humidity until the Internet (blessed Internet) came alive to make us all aware of minutia about which we could obsess.

I do humidify my main guitar room, and guitars are damaged by insufficient humidity, but – in all those years BI (before Internet) I never had so much as a crack due to winter dryness. Go figure.

[Pheof]

If the storage facility is not temperature controlled it may actually be a good thing (within reason). Colder air holds humidity better than heated air (not summer heat, but manual heat such as your home heat). Therefore, if you store a guitar in an uncontrolled environment, and let's say the temperature drops down to 50F while the humidity remains at 40% or above, it's going to be much better off than a guitar in a heated home at 72F where the humidity is dropping to 25% or less during Dec, Jan, Feb and Mar.

Here are some other comments while we're on the topic:

Natural humidity refers to both humidity, air density and air pressure. Artificial humidity merely spouts moisture into a room, and it's ever-ready to dissipate from the moment the source stops. Totally different. Also, I'll exaggerate to make the next point: if you put a 2 gal humidifier in the middle of a 500 sq foot room, and had 2 guitars next to the humidifier and 2 guitars 20 feet away, AND the humidifier read a consistent 45%, you can expect that the two guitars 20 feet away are not being maintained at the same 45%. This principle applies to guitars in your smaller home. My point is that there are major significant differences between natural summer humidity and the use of artificial humidification. With artificial humidity, it's just as easy to under-humidify as it is to over-humidify.

If that makes sense, and for what it's worth.

[fazool]

Originally Posted by DesolationAngel

... I keep my guitars within a decent range of temperature and humidity but try not to obsess and stress over it.
...

Then, you're doin' it wrong (jk)

Originally Posted by DesolationAngel

...one of my guitars was in a case and in a public storage facility that isn't temperature or humidity controlled. It stayed out there for the whole winter. I checked on it a couple of times and it was a-ok; no warps, no cracks, nothing. .....So, my question is... how come? It's a solid spruce topped jumbo with quilted maple back and sides. It was detuned and in a Hiscox case. Did I get lucky? Are those Hiscox cases really good? Is maple more resistant to cold/low humidity than other woods?

Just curious...

I think of it this way:

Without any owner-care, any and every guitar has a 10% chance of cracking by low humidity.

With diligent care, any and every guitar might have a 0.1% chance of cracking.

So, by far you still have a 90% chance of being just fine.

The whole humidity monitoring and care effort is aimed at not being in that 10%.

Sort of like car insurance. You buy it, pay for, go through all the trouble of having it, fully expecting/hoping that you are in the 90% that never needs or uses it.

[Von Beerhofen]

If in these storage spaces temperatures are more or less the same as outside the humidity indoors will also be the same as outside. Depending on the climate band you're living in it's not unthinkable that outside humidity wasn't far off from the ideal averages for longer periods of time. On top of this any changes outside will take some time to change indoors as well and inside a case it'll take even longer. Even with high outdoor humidity an indoor facillaty will take quite some time for it's temperature to sink as low as outside but sunshine may add more heat which again will sink Rh.
In my own situation, I'm not using any heating or airco, but my appartment does have double glazing and catches a lot of sunlight when there. Rarely temperature will drop below 15 Celsius indoors but it could be freezing or close to it outside. With outside humidity levels up to 90+ Rh the indoor temperature raises that to a nice 40 to 60Rh. Additionally I've stuffed all my cases with newspaper which act as an additional buffer for swings.
Ofcourse my local weather station is monitored twice a day and if there's a dry spell I'll humidify.
I think you've been lucky as you didn't monitor local weather, temperature or ouside Rh as I do. Next time you might not be so lucky.
BTW, there are tables with which you can translate outdoor Rh to Indoor Rh, provided you know the temperatures inside as well as outside.

Ludwig

[fishstick_kitty]

I think certain guitars are more susceptible to cracking due to dryness...and others aren't. Even from the same maker. You will hear stories of "I bought a bla bla acoustic in the 70s and used it as an ice scraper and threw it in the trunk or under the deck and it never cracked" . I would say you got lucky...that particular guitar is just less susceptible.

[Lacks Focus]

It's important to note that there is less moisture in 50-degree 45% RH air than there is in 72-degree 45% RH air. Don't make the mistake of thinking your guitar is as happy in the former as it is in the latter. 50d/45% air is much dryer than 72d/45% air.

If your guitar is put into an environment with dryer air than it was manufactured in (assuming your luthier allows sufficient time for his build woods to acclimate and achieve equilibrium before construction), your wood will lose moisture.

How much it will dry, and how detrimental the drying will be, are the things that are open to debate. Some guitars are incredibly sensitive, while others seem oblivious to changes in environment.

[Woodstock School Of Music]

I just got my room setup with a room humidifier and I have a question.

I've read that it's recommended that you turn down the humidity as the temperature drops because of possible condensation damage. Do you people using room humidifiers adjust for that or do you always try to keep the humidity at 40-45? Thanks

[Rodger Knox]

Originally Posted by Lacks Focus

It's important to note that there is less moisture in 50-degree 45% RH air than there is in 72-degree 45% RH air. Don't make the mistake of thinking your guitar is as happy in the former as it is in the latter. 50d/45% air is much dryer than 72d/45% air.

If your guitar is put into an environment with dryer air than it was manufactured in (assuming your luthier allows sufficient time for his build woods to acclimate and achieve equilibrium before construction), your wood will lose moisture in 50d/45% air.

How much it will dry, and how detrimental the drying will be, are the things that are open to debate. Some guitars are incredibly sensitive, while others seem oblivious to changes in environment.

That is completely incorrect. Moisture content in wood is an equilibrium situation, and the equilibrium depends on the relative humidity.
It is correct that 50d/45% air contains less moisture than 72d/45% air, but the equilibrium moisture content of wood(approx. 7% at 45% RH, depending on species) is the same for both.

[nootis]

I learned the hard way, and prior to my knowledge of this forum (even though the internet has always been available). I am sure it is because I am more susceptible due to the fact that I live in the desert. I used to keep my Martin on the wall inside my home, and I also had a Koa Taylor T5 that also stayed out. After many years of this practice, the Martin developed a split on the neck just below the headstock where your thumb or hand would be. The Taylor started to show some finish "bubbles" near the electronic volume knob (I thought it was a defect so I sent it to Taylor). My local luthier fixed the Martin (you can still see evidence of the crack though, but it is stable), and Taylor informed me that my guitar was super dry so they re-hydrated and repaired it (I had to pay). I then started keeping my guitars in their cases using Oasis humidifiers, and now I've built a guitar humidor out of a closet.

The short answer is that all solid wood guitars are better off being in a controlled humidity environment, and depending on where you live will depend on how much attention needs to be given.

[fazool]

Originally Posted by The dman

I just got my room setup with a room humidifier and I have a question.

I've read that it's recommended that you turn down the humidity as the temperature drops because of possible condensation damage. Do you people using room humidifiers adjust for that or do you always try to keep it at 40-45? Thanks

No, Unless the temperature in your room swings 20 degrees, you won't see a problem.

40-45 is my sweet spot ( a tiny bit lower than the common 45-55 thinking) but its easier to maintain and further from condensation also.

[Lacks Focus]

Originally Posted by Rodger Knox

That is completely incorrect. Moisture content in wood is an equilibrium situation, and the equilibrium depends on the relative humidity.
It is correct that 50d/45% air contains less moisture than 72d/45% air, but the equilibrium moisture content of wood(approx. 7% at 45% RH, depending on species) is the same for both.

So you're saying a piece of wood that's reached equilibrium in 50d/45% air contains the same amount of raw moisture as an otherwise identical piece of wood that's at equilibrium in 72d/45% air? If that's true, then there's no need to worry at all about the RH environment of our instruments.

[Pheof]

Originally Posted by The dman

I just got my room setup with a room humidifier and I have a question.

I've read that it's recommended that you turn down the humidity as the temperature drops because of possible condensation damage. Do you people using room humidifiers adjust for that or do you always try to keep it at 40-45? Thanks

A little condensation on the windows isn't bad. But if it begins to drip and form small puddles, you should lower it. You don't need specific charts or figures to know when to lower it. But the colder it gets the lower your humidifier needs to be in order the keep condensation minimal. Another thing is you'll notice you're adding water much more frequently. The object is to help the guitar survive, not so much to baby it. 35% humidity isn't gonna make the top crack in 4 weeks usually, you might get sharp fret ends and low action, but any lower than that is asking for trouble. There's no point in keeping your guitar at 45% if you're going to have to replace 8 windows in your house. Artificial humidification isn't as good as natural, but it will keep your guitar safe and that's all that matters. One last tip: if you can, store your guitars and humidifier in a room that's normally cooler than the others. Cooler air retains more moisture and will help prevent window condensation. Your guitars would be fine at say 60F and 40% RH, if that were the case. Let the rest of the house be 68F, 70F, 72F, whatever.

[ljguitar]

Originally Posted by The dman

I just got my room setup with a room humidifier and I have a question.

I've read that it's recommended that you turn down the humidity as the temperature drops because of possible condensation damage. Do you people using room humidifiers adjust for that or do you always try to keep the humidity at 40-45? Thanks

Hi dman...

When the windows are dripping/freezing and pooling, I turn it down. Actually by watching local weather I can lean into it and avoid the whole mess by turning the humidifier down before we get to that point.

People who don't live in extreme regions have no idea how much water will condense on the inside of a warm house when severe temperature drops to below 0°F occur. It happens to us 3-4 times per winter and lasts from 3-7 days at a time.

Just watch the windows and you will know what to do.