So how close to 40-55% humidity should I be?

Discussions relating to the classical guitar which don't fit elsewhere.
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Andrew Fryer
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Re: So how close to 40-55% humidity should I be?

Post by Andrew Fryer » Mon Jan 22, 2018 4:58 pm

My thermometer/hygrometer is by TFA-Dostmann. It's more than adequate. It's only about £12 on Amazon. It looks like this: -
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JohnB
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Re: So how close to 40-55% humidity should I be?

Post by JohnB » Mon Jan 22, 2018 5:37 pm

The hygrometer on the Burgess Violins website looks as though it is a "Caliber IV". I have two of these (not from Burgess Violins) and they are very accurate indeed. (I believe it was originally designed for finickety cigar enthusiasts.)
Hermanos Conde 1968, Stephen Frith 2007 "Guijoso"

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Andrew Fryer
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Re: So how close to 40-55% humidity should I be?

Post by Andrew Fryer » Mon Jan 22, 2018 5:58 pm

JohnB wrote:
Mon Jan 22, 2018 5:37 pm
(I believe it was originally designed for finickety cigar enthusiasts.)
Lol. I had a thermidor once. I used to stick a wet sponge in it. I couldn't get those cigars damp enough - I'd smoke them if they were mouldy!
1975 Calatayud y Gisbert, Yamaha CG131S.

soufiej
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Re: So how close to 40-55% humidity should I be?

Post by soufiej » Mon Jan 22, 2018 8:06 pm

"The hygrometer on the Burgess Violins website looks as though it is a "Caliber IV". I have two of these (not from Burgess Violins) and they are very accurate indeed."


Yep! that's the model. Looks just like the Caliber IV I own. I was surprised to see the $30 price just for "calibrating" the meter. As stated, +/- 5% really is accurate enough.

You are a lucky man. I have to carry mine from room to room if I get curious. Otherwise, I just rely on the meter in the automatic humidifier that deals with the front half of the house. Now, I've read that's not a great place for a meter because those meters built into a humidifier only read the moisture right in front of the humidifier. To which I ask, how much more could I ask? It's not like the R.H. here in front of the humidifer is 30% different than the R.H. over there if the multi-room humidifier is doing what it was sold to do.

There just seems to be so much stress involved with R.H. values.

amade
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Re: So how close to 40-55% humidity should I be?

Post by amade » Tue Jan 23, 2018 4:00 am

I asked the luthier Marshall Bruné how long it takes for the tone woods of a guitar to absorb or lose moisture. He said this was a matter of many days and not hours (back/sides at a different rate than tops). When Richard and Marshall repair instruments that have dried out and cracked, it takes days or even weeks in a well humidified environment to get the instrument back to it's normal shape. So I assume that there is no need to place your guitar in a humidified case when taking a break from practicing in a dry environment.
DJB

1966 Anselmo Solar Gonzalez (SP/Mahogany)
1970 Jose Ramirez 1a (CD/BR)
1970 Masuru Matano 300 (CD/IR)
1972 Aria AC 40 (CD/IR)
1979 R. E. Bruné Baroque lute
1980 R. E. Bruné Renaissance lute
1990 K. Yairi T-10 (SP/R)

Jeffrey Armbruster
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Re: So how close to 40-55% humidity should I be?

Post by Jeffrey Armbruster » Tue Jan 23, 2018 4:30 am

My uninformed guess would be that it's the untreated wood inside the body of the guitar, as well as the braces, that would be the most vulnerable. That's why I wonder about the wisdom of not putting a Humidipak inside the body of the guitar, as some prefer to do.
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soufiej
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Re: So how close to 40-55% humidity should I be?

Post by soufiej » Tue Jan 23, 2018 3:02 pm

"My uninformed guess would be that it's the untreated wood inside the body of the guitar, as well as the braces, that would be the most vulnerable. That's why I wonder about the wisdom of not putting a Humidipak inside the body of the guitar, as some prefer to do."


It's fair to assume the thinner pieces of wood will be the most reactive to moisture loss and gain. It would also be reasonable to assume different woods, though they have been "cured", will retain different amounts of oils which resist a change in moisture level. Rosewood is very dense and contains quite a few oils while, say, generic maple is, when plane cut, not as dense and is not filled with the same amount of oils. How the wood is cut will expose more or less end grain. Quartersawn wood, the type most often used for top and back woods, shows the grain pattern but does not expose excessive amounts of open grain to the environment. Quartersawn wood is the strongest wood across the grain for any species/variety which gives it the preferred characteristics for a musical instrument.

Think about putting a thin sheet of wood in an uncontrolled environment along with a 2X4 piece. Which is the most likely to react to the environment first? The 2X4 represents the neck material on your guitar.

The problem the accessories manufacturers were presented with was simple, how to humidify the neck? Lacking a good answer to that question, the next issue became how to sell a "guitar humidifier"? Oh! look! there's a hole in the top plate!

I would say you are best to realize your guitar is not one, big, monolithic thing. It is made up of parts and most of those parts are not the same wood variety as the rest. The woods are all cut to different thicknesses and the manner in which the pieces are cut may vary from piece to piece. Due to the way quartersawn uses the log, it is also the most wasteful of the entire log.

There are multiple reasons for damage to occur and there's simply no way to address each without somehow cheating the others.

Also, soundhole humidifiers begin by releasing a good amount of moisture into the interior of the guitar. Soon the sponge or other device begins to loose its moisture which means it is giving up less to the guitar. Unless you constantly monitor and refresh the soundhole humidifier, you are actually exposing the interior of the guitar to far greater extremes than had you simply not used the humidifier.

This is not an argument against soundhole humidifiers, it is simply pointing out the obvious. If you live in an extremely dry climate or where the HVAC system is removing a good amount of moisture from the room, then you might find they have their place. Just stay on top of the amount of moisture in their sponge. Consistency, not extremes, is the key to maintaining your instrument.

Jeffrey Armbruster
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Re: So how close to 40-55% humidity should I be?

Post by Jeffrey Armbruster » Tue Jan 23, 2018 5:47 pm

Well, it's very easy to tell when a Humidipak has dried out. Moreover, they keep a more or less constant humidity level inside of a guitar case--especially if you have a case that seals effectively. They also humidify a dry case. when the RH is within 45-55% in my apartment, I just leave both "paks" in the headstock area of the case; outside of that I definitely put two into the interior of the guitar. So the RH inside of my case is more consistent than it is outside of the case.

My thought is that the lack of any French polish or other treatment to the interior wood makes it more liable to rh variations. Maybe not!
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Rasputin
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Re: So how close to 40-55% humidity should I be?

Post by Rasputin » Tue Jan 23, 2018 6:03 pm

The finish thing makes sense to me, athough it only really makes a difference if you are going for a very localised solution like a humidipak.

I'm a bit dubious about the idea of humidifying a closed case, as there is next to no air movement in there. I guess if dry air sucks up moisture very readily, that is not a problem - it will be absorbed by the air right next to the humidipak, then pass into to the surrounding air the way water passes through a sponge. On the other hand, if that is right, it doesn't really matter where in the case you put the humidipaks. If you think about laundry drying, it makes a huge difference whether it is windy - at least it does in places where the outdoor RH is high. Maybe it doesn't matter if the RH is low enough for there to be a risk of damage to your guitar.

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Re: So how close to 40-55% humidity should I be?

Post by rpavich » Tue Jan 23, 2018 6:22 pm

Rasputin wrote:
Tue Jan 23, 2018 6:03 pm
The finish thing makes sense to me, athough it only really makes a difference if you are going for a very localised solution like a humidipak.

I'm a bit dubious about the idea of humidifying a closed case, as there is next to no air movement in there.
That's the entire concept behind the Humicase.
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Rasputin
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Re: So how close to 40-55% humidity should I be?

Post by Rasputin » Tue Jan 23, 2018 8:53 pm

Forgive my cynicism, but I'm still dubious. Maybe they work, maybe they're like Lisa Simpson's rock.

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prawnheed
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Re: So how close to 40-55% humidity should I be?

Post by prawnheed » Tue Jan 23, 2018 9:01 pm

Rasputin wrote:
Tue Jan 23, 2018 8:53 pm
Forgive my cynicism, but I'm still dubious. Maybe they work, maybe they're like Lisa Simpson's rock.
I think they work as well as any other case with a damp sponge inside.

JohnB
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Re: So how close to 40-55% humidity should I be?

Post by JohnB » Tue Jan 23, 2018 9:08 pm

Rasputin, I'm not quite sure what aspect you are dubious about. If it is about leaving the humidipaks in the case and closing the lid when the guitar is removed, the reasoning is that if the case is left open in a low RH environment the interior will tend to dry out slightly, presenting an extra "load" on the humidipaks when the and the guitar are returned. (The humipaks only contain a limited amount of usable water, at a guess 15-20ml each.) If you are going to close the case, it makes sense to leave the humidipaks inside it, especially as most cases are not airtight.

They work differently to the damp sponge type of humidifiers, in that they will attempt to maintain a set RH.
Hermanos Conde 1968, Stephen Frith 2007 "Guijoso"

Gustavosamor
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Re: So how close to 40-55% humidity should I be?

Post by Gustavosamor » Tue Jan 23, 2018 9:20 pm

rpavich wrote:
Thu Jan 11, 2018 7:01 pm
Well the guitar came and it came safely!

It's tuned up and I put the DIY humidifier and hygrometer in the case with it.

One observation; when I stopped playing 7 years ago I wasn't that great, now I absolutely reek. Holy Smokes...it's like I never held a guitar before!

Practice, practice practice.
By the way, have you dig into the "Two-Way Humidification" by D'addario....they are quite nice and worries free!

Rasputin
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Re: So how close to 40-55% humidity should I be?

Post by Rasputin » Tue Jan 23, 2018 9:27 pm

JohnB wrote:
Tue Jan 23, 2018 9:08 pm
Rasputin, I'm not quite sure what aspect you are dubious about. If it is about leaving the humidipaks in the case and closing the lid when the guitar is removed, the reasoning is that if the case is left open in a low RH environment the interior will tend to dry out slightly, presenting an extra "load" on the humidipaks when the and the guitar are returned. (The humipaks only contain a limited amount of usable water, at a guess 15-20ml each.) If you are going to close the case, it makes sense to leave the humidipaks inside it, especially as most cases are not airtight.

They work differently to the damp sponge type of humidifiers, in that they will attempt to maintain a set RH.
I'm just not clear how the moisture is transferred into the wood, and would like to understand this in the interests of cultivating my inner spod. If it depends on circulation of air (a bit like convection) then it probably doesn't work at all, it seems to me. Conversely, if it does work then it cannot depend on circulation of air, in which case we are saying that dry air will suck up moisture so readily that it will spread through the air like water in a sponge, and from the air which is in contact with the wood into the wood itself (a bit like conduction). That sounds plausible to me but is not what we observe with washing lines on still days, at least in temperate climates... but maybe that is different because outdoor RH is high in temperate climates, whereas we are only concerned with situations where RH is low.

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