Annual Humidity post - SUPER IMPORTANT - READ THIS!!!!!!! (long, but worth it)

Light

New member
So, it's that time again. The time when I berate you all to humidify your guitars during heating season.

The specific requirements for humidity in your region will vary depending on your climate, but I live in the absolute worst part of the country for humidity, where it will go up and down about 60-80% over the course of the year, from low to mid 80% in the summer to as low as 5% indoors during the winter. These huge swings are killers for guitars, and in our shop we frequently see as many as 600 guitars over the course of the winter with humidity related problems (it gets a little busy!). So do what you can to take care of it.

Up here where I live, we never get so humid that you need to worry about your guitar getting too much humidity, though if you live in a swampy area you might have that problem. The problem here is low humidity. Guitars like to live in 40-50% relative humidity.

Houses being heated to 72 degrees Fahrenheit when the temperature outside is in the 10 degree range can easily get down to about 5%, and when it is 35 below I've seen it go as low as 2-3%. This is a particular problem on acoustic guitars, which are usually unfinished on the inside, so they will lose moisture to the surrounding air, which will cause the wood to shrink. This leads to all kinds of problems, from the top sinking (which pulls down the bridge, which pulls down the action and causes buzzing - some guitars come in and you can see from across the room that the tops look like salad bowls), to the wood cracking. Now, all of these things can be repaired, of course, but it is much better to avoid them if you can.

Electrics have fewer problems, but one thing which can be a problem for both acoustic and electric guitars is the fingerboard shrinking. When this happens, the frets do NOT shrink. On an unbound fingerboard, this is relatively minor, with the fret ends sticking out and acting like a serrated knife when you move up and down the fingerboard. It is painful and problematic, but it's pretty cheap to have fixed (we usually charge about $30 for it); but on a bound fingerboard, as the frets push out from the wood, they can cause the binding to come unglued, which can lead to all kinds of problems, and which is much more time consuming (i.e., expensive) to fix. And unfortunately, while a sinking top will usually come back with adequate humidification, fingerboards are too thick, and will never come all the way back.

So, what can you do about it? Glad you asked.

First, from the moment you turn on your furnace (or whatever kind of heat you use - even steam heat, which somewhat counter-intuitively is one of the worst for causing low humidity), you MUST be humidifying your guitars. I usually recommend that my customers put a little post it note on the furnace or by the thermostat reminding them to humidify their guitars. In my part of the world, I've got no real problem with people keeping up the humidifiers year round if that is what it takes for them to keep it up during the winter, as in the 35+ years we've been in business the only guitars we've seen which had been over humidified had spent a week or two in flooded basements.

There are several options for this, and some people like to just humidify the room they keep their guitars in, but this has some major problems. First of all, if you live in a wood house with windows, you will have a very hard time keeping the room up where your guitars want to be, 40-45% relative humidity. When it's really cold out, at about 35% the moisture just starts to condense out on the windows and you don't get any higher without putting massive amounts of water into the air. But even that has problems, because it is not just your windows the moisture is weeping out on (though, considering the mold and mildew this will cause, it's a serious enough problem), but also the studs in your walls. It will condense out and freeze on your stud walls, and you can literally rot your house from the inside out. If you are in a masonry or concrete building, you can get aways with it, but it is still problematic (because of the work we do, we MUST keep our concrete block shop at 45-50% year round, and we get some pretty serious mildew stains on some of the walls because of this).

So, what do you do if you want to keep both your house and your guitars in good shape in a cold environment? First and foremost, keep your guitars in their cases whenever you are not playing them. This is a pain (it's much easier to play a guitar that is sitting on a stand and all that), but if you want to keep your guitars in good shape it is essential, partially because it means that you have a much smaller space to humidify, but also because it will protect your guitar from knocks, bumps, and little curious hands who want to try daddy's (or mommy's) guitar. I've said it before, and I'll say it again, but ALWAYS KEEP YOUR GUITAR IN IT'S CASE, as it is never safer than when it is in it's case.

In order to maintain the guitar's humidification, I recommend a two humidifier solution. First, get a KYSER LIFEGUARD. They are, hands down, the absolute best investment you can make in maintaining your guitar in a dry climate. They are infinitely better than any other guitar humidifier on the market, and I'm not just saying that because I know the inventor (he sold the idea to Kyser about 15 years ago, and doesn't get shit from them anymore). They lock the humidity into the body of the guitar, where (because it is unfinished on most guitars) it is most vulnerable to low-humidity conditions. Other humidifiers are either too small, too difficult to fill, or they have hard plastic cases which can damage your guitar. The only tricks with the Lifeguard are that you must throw out the harder black packaging ring they come with (he actually intended it for guitars with very thin tops, but I've never see a guitar which need one), and you must be very careful to get all of the water out of the various crevasses on the outside of the humidifier. I fill it under a running tap (there is absolutely NO need to use filtered water, and anyone who says otherwise is just silly) until it is wet, but not dripping when squeezed, then I dry off the exterior with a paper towel (being very careful to get under the lip that holds it in the guitar), and put it in the soundhole. You can even play with them in, which can be handy if your SO is sleeping in the next room. They come in two sizes, one which will fit most round holed steel stringed guitars (model KLHA), and one for guitars with smaller soundholes (usually classical guitars or Martin O or OO sized guitars - model KLHC).

Second, go to Target and get yourself a covered plastic travel soap dish and a sponge. Drill some holes in the soap dish cover, put the (now damp) sponge in the soap dish, and put the whole thing in the case with your guitar. They usually fit quite nicely up by the peghead. You can also put a rubber band or old tee-shirt around it to keep it from falling open, and I had one customer put some Velcro in their case to hold it in place.

Check these humidifiers every time you play, but at least every 3-4 days in really cold weather (a bit less in warmer weather, but your playing your guitars every day, right? So checking their humidifiers will be no problem, right?). When they stop feeling damp, refill them. DO NOT FORGET TO REFILL THEM! If you do, don't complain to me when you have to pay $150 or more to get your guitar fixed. You've been warned.

If you live in a milder environment, you might not need to be so aggressive about this, but the flat truth is that unless you live in a swamp or use it as a canoe paddle, you will never get your guitar so over-humidified as to cause problems. It might sound a bit dull, but you will not cause damage to the guitar.

Always check with your local repair shop to determine the appropriate steps to keep your guitar safe in YOUR climate, but if you need to turn your heat on for more than a day or two at a time, you need to be humidifying your guitar.

With any luck, Muttley will chime in with what he recommends for people in cool damp climates like the British Isles.

Sorry this is so long, but it's important, and there is a lot of information you need to know if you want to maintain your guitar properly.



Light

"Cowards can never be moral."
M.K. Gandhi
 
Do I have to humidify my electrics?

Come on muttley, tell us what to do on the other side of the pond!
 
Do I have to humidify my electrics?

Come on muttley, tell us what to do on the other side of the pond!

Read the above. ;)

We do have issues concerning humidity and extremes of temperature here and in Ireland but they are not as severe as Light has described his region to be.

The only things I'll add would be that the one thing timber in general and guitars in particular really don't like is swift changes. Take special care when you transport your guitars. Going from home to a gig the guitar even in it's case is going to suffer from changes in relative humidity and temp. Try and let the guitar acclimatise for as long as you can when you go from out doors to indoors. Dont leave them in the boot of the car for longer than is absolutely necessary.

The humidity in our homes as a rule when we turn on the central heating levels out somewhere close to the ambient humidity that occurs during our summers. The best way to keep an eye on things is to get a barometre and watch it over time. Learn about the changes that occur in your area. Where I grew up in Cornwall on the Atlantic coast has a very different climate than I experience here in and around London. If your at all concerned follow the advice that Light has given it will do no harm. It is a good idea to do a little research to understand your local climate.

Most of the issues I see around this timenof year are to do with setups and buzzes caused by humidity problems. Guitars are like you and me in many regards. It's no mistake that chest infections, rheumatism etc are worse at this time of year its your body reacting to changes in the weather your guitar does the same. If you feel the setup has changed thats why. I always reccomend a winter and summer check to all my clients to keep things smooth. That dosen't have to be a full setup just a check over and maybe a little truss rod adjustment and tighten everything up, polish the frets etc.. Its better to deal with any issues that way than let them get worse due to the weather.

A lot will depend on what, where and how your store your guitars. Do you take em out lots? How long for? What guitars? Where you are in relation to the coast? Get a barometre and take a look at the difference inside and out over a period of time. It will give you an idea of what your guitar has to cope with.
 
Whoops sorry, I did skim through it but I focused on the product that was for sale. I tend not to take my guitar out of my bedroom....it never goes to gigs or leaves my house. But I guess it's no harm to over-humidify.Thanks guys.
 
sometimes I feel like a walking barometer (ol' age haha), and muttley is correct with keeping one on hand, this is very important stuff that Light has said about guitars, but we also have drummers in bands that can suffer the same consequences with wood shells...I live in NW Florida USA, and its a swampy haven with temps and humidity that can vary daily, even overnight here we can go from 75 degree t-shirt weather in the daytime to 20 degrees at night and the humidity is up and down all over the barometer. I try to keep my studio below 60 and above 40 percent, no easy task, but do-able with 50 percent at perfect. For those that live in snowy country (where I am originally from) don't haul your guitar or drums in a trunk, always haul them in a heated space, like a van or inside a car...I've seen freezing temps "crack" wood...and this is probably due to the moisture that has been collected in the wood first off. Even here in Florida there are changes in the gear that needs to be "relaxed" before we tune and play, let it get use to the new environment before playing...humdity and temp changes are tricky. jmo's thanks guys!
 
Great post Light.

Here in the desert we laugh at humidity. Rarely does it ever reach the ideal of 35 to 40% humidity to make an instrument happy. As said earlier, one of the most important things is that acoustic instruments don't like extreme change so be careful when you take your stabilized D-28 out of its case and play it by a toasty fire for a couple of hours on a cold winter night.....you're asking for trouble.

Keeping your instruments in their cases is the best thing you can do, and humidifying acoustics really helps setup and playability as well as protect. As an example of how much humidity changes things is my Eastman 810 CE archtop. Since I bought on spec out of Denver a few years ago the carved top has risen and stabilized nearly 3/8 of an inch higher than when it arrived.

As to what to use I tend to go with a sponge in plastic string pouch cause they'll fit nearly anywhere in the case. Wooden cases go about 5 days before the sponge dries and SKB type plastic cases go up to two weeks. What the actual humidity is in there I have no clue, I just know that it works.
 
Light - thanks for the informative post, and thanks to Muttley for the follow-up.

So, keeping things really simple for a simpleton such as me - an in-case humidifier consisting of a damp sponge in a drilled travel soap container will give me all I need for my electrics? Why didn't anyone tell me this years ago?

Is this something that should live in your case year-round? In my part of the country we only have maybe 3 months out of the year when we aren't running either a heating furnace or a cooling air conditioner, both which reduce humidity in the house.
 
What's barometric pressure got to do with humidity? I think possibly the instrument you are thinking of is a hygrometer (http://en.wikipedia.org/wiki/Hygrometer).
In this countries climate a barometer will tell you a lot about the atmosheric water content. Next to no average person would know where to get or how to calibrate a hydrometre. A decent hydrometre that gives reliable results will often cost more than the guitar itself. A barometre will tell you the change in atmospheric pressure and in nearly all cases it is a related to the vapor in the air. What you want to measure is the swift change in the prevailing conditions not the exact amount of moisture. At a cost of £5 for a decent barometre against £200 for an average quality hydrometre you can get all the information you need to identify that the degree of change in air vapor is great and get a good idea of the impact seasonal changes have. We arn't really interested in meteorological accuracy of the results just that the moisture in the air changes swiftly and to a significant degree.
 
Good post Light.

I don't worry about humidity now as my guitars always reside in a room in my Virginia home that I am able to keep the level relatively constant in a good range. However, within a year or two we plan to move to Tucson AZ, where I am sure that lack of humidity will be a real problem. So thanks philboyd studge for the commentary from the desert. It's to know that desert conditions can be dealt with. (Where are you at by the way?).

Please correct me if I am wrong, but common sense tells me I should be less worried about my electric than the acoustics. One of the latter is a cheapy import left over from my son's short lived interest in learning to play guitar. But the other is a rarely played vintage Martin 12-20 12-string that is currently in very good condition I hope to find an interested buyer locally and sell it before moving, just sos I don't have to worry about it. Otherwise, I guess the LIFEGUARD thingy combined with the damp sponge would seem to be perfect for keeping it in good shape.

Thanks again to the info guys.

Tom
 
In this countries climate a barometer will tell you a lot about the atmosheric water content. Next to no average person would know where to get or how to calibrate a hydrometre. A decent hydrometre that gives reliable results will often cost more than the guitar itself. A barometre will tell you the change in atmospheric pressure and in nearly all cases it is a related to the vapor in the air. What you want to measure is the swift change in the prevailing conditions not the exact amount of moisture. At a cost of £5 for a decent barometre against £200 for an average quality hydrometre you can get all the information you need to identify that the degree of change in air vapor is great and get a good idea of the impact seasonal changes have. We arn't really interested in meteorological accuracy of the results just that the moisture in the air changes swiftly and to a significant degree.

Then I guess I really don't get it. Didn't you advise using a barometer to measure the difference between indoors and outdoors? I don't see how barometric pressure can be different between the two. Humidity, yes. And as Light says, when you heat the air in your home, you decrease the relative humidity in that air, and the barometric pressure has not changed.

And here's one for less than a hundred bucks:
http://www.reliabilitydirectstore.c...di-ar837.htm?gclid=CLD5-YbRuY8CFQ83gQod8jAUsA
 
Then I guess I really don't get it. Didn't you advise using a barometer to measure the difference between indoors and outdoors? I don't see how barometric pressure can be different between the two. Humidity, yes. And as Light says, when you heat the air in your home, you decrease the relative humidity in that air, and the barometric pressure has not changed.

And here's one for less than a hundred bucks:
http://www.reliabilitydirectstore.c...di-ar837.htm?gclid=CLD5-YbRuY8CFQ83gQod8jAUsA

A barometer will give you an indication of the absolute humidity of a column of air and its relation to the weight of that column of air. Atmospheric pressure is related to the amount of water within a given column of air. A hydrometer will give you an indication of specific humidity at the place at which it is measured. I have not suggested that a barometer will measure humidity for you. I have always said it will give you an indication of the manner in which humidity and vapor pressure change in relation to seasonal changes, specifically in the British Isles. This it will do. Taking measurement both inside and out over a period of time also give an indication of the importance of temperatures and vapor pressure in the relationship. The key here is using a barometer to demonstrate that the temperature and vapor in the air will change swiftly and mean values for summer months are different from winter months. Not that the moisture is actually there in the first place. You don't need an expensive hydrometer to do this. By all means use one if you need the data to be that accurate.

In one sense your guitar is a barometer in that it will react reliably to the same phenomena that the barometer is measuring.
 
Good post Light.

I don't worry about humidity now as my guitars always reside in a room in my Virginia home that I am able to keep the level relatively constant in a good range. However, within a year or two we plan to move to Tucson AZ, where I am sure that lack of humidity will be a real problem. So thanks philboyd studge for the commentary from the desert. It's to know that desert conditions can be dealt with. (Where are you at by the way?).

Please correct me if I am wrong, but common sense tells me I should be less worried about my electric than the acoustics. One of the latter is a cheapy import left over from my son's short lived interest in learning to play guitar. But the other is a rarely played vintage Martin 12-20 12-string that is currently in very good condition I hope to find an interested buyer locally and sell it before moving, just sos I don't have to worry about it. Otherwise, I guess the LIFEGUARD thingy combined with the damp sponge would seem to be perfect for keeping it in good shape.

Thanks again to the info guys.

Tom

I'm on the East side of the Coachella Valley. Since humidity is often in the teens here, it's pretty low in the house after the heat pump gets done heating or cooling the air and that presents another set of problems; that's the natural enviornment here so if you're taking your guitar out its humidfied case you're exposing it to extreme change, whadda ya do? Basically not much, just keep instrument out no longer than it has to be, up to 4 hours or so, and if there's no huge in temperature you should get through things ok. Some folks here don't do anything to humdify and reset setup and action for the lowered top but you're asked for eventual finish checking, possible cracks and loose braces.

I had a D12-20 for quite awhile but sold it about ten years back....at a time I was doing little to humidify my acoustic guitars. Only the J-200 as I recall. Anyway, the Martin held up well and had no finish or neck issues and was a testimony to the most important thing you can do....keep it in its case and away from extreme changes. Though it would have been better to humidify it somewhat I got by and was lucky.
 
So, keeping things really simple for a simpleton such as me - an in-case humidifier consisting of a damp sponge in a drilled travel soap container will give me all I need for my electrics? Why didn't anyone tell me this years ago?


Yup, pretty much.

As for the hygrometer issue, we have a really nice one in the shop, and it typically reads within 4-5% of the cheap ass digital ones we have up throughout the shop. The cheap ones will not give you a perfect reading, but they will give you a close approximation, which is all you really need. If you see a big change in them, then you know you need to take some action.

We have an old super nice hygrometer with a good humming bird wing diaphragm (yes, they are really made of humming bird wings) that we almost never look at other than to double check on the cheap ones. Really, though, it's not that important that you know exactly what it is unless you are trying to humidify a room. Otherwise, just start humidifying as soon as you turn on your heat, and you'll be fine. Though air conditioners (cooling) DOES lower the humidity, we have never seen a single guitar that was cracked from it. All the ones we see in the summer are of the "Yeah, it cracked last winter, and I just didn't get in until now," variety (with all the dirt and grime in the cracks which goes with it), and never of the, "this crack just showed up," sort.

As far as cold, though it is certainly possible for it to cause wood expansion, I've never seen structural damage from cold (and we get bloody cold up here). The cold issue we DO get a lot of is weather checking, which is from a cold guitar suddenly getting too warm. The wood expands faster than the finish, and you get many fine cracks in the lacquer. This one happens all the time, and there isn't really much you can do to repair it. Their are several ways to avoid it, starting with the builder using a vinyl sealer instead of a straight sanding sealer (it's more flexible), but the main thing for the player to do when their guitar gets too cold (left in a case in the trunk on a cold day, for instance) is to leave it in the case until it has come to room temperature. When customers ship us guitars, we will leave them in the box for at least a day. The point is to slow down the speed of the temperature change so that the process happens more gradually and the lacquer never gets too stressed.

But again, weather checking is really only a cosmetic problem (though it can effect collectible value, so be careful with those old Strats and D-28s), so I don't worry TOO much about it with my own guitars. With a customer's guitar, I'm fanatical about it, of course, but I don't mind playing a guitar that looks lived in, personally. Humidity issues are serious structural issues, so I worry a LOT about those.


Light

"Cowards can never be moral."
M.K. Gandhi
 
A barometer will give you an indication of the absolute humidity of a column of air and its relation to the weight of that column of air. Atmospheric pressure is related to the amount of water within a given column of air.

I'm sorry, but I don't see how that could be true. Humidity is not a constant top (meaning to the top of the atmosphere) to bottom in the column of air; it's a local phenomenon, especially if you are in a building where it can be quite different from what it is outside. Absolute humidity doesn't determine the drying ability of air, either; relative humidity does, which is exactly what Light was saying. When you heat air which is at 10 degrees F to 75 degrees F, its absolute humidity does not change, but the relative humidity will drop from (possibly) 100% to very much less than that, putting your acoustic instruments at risk.

And are you saying that a barometer will register a change if you go outside a building that has a different relative humidity than ambient, even if it is not sealed? I can't see how that could be true; the pressure would equalize whenever you opened a door even if it were sealed. Furthermore, while it is true that wet air weighs more per unit volume than dry air, days of high barometric pressure are frequently (usually, even) dry. That would seem to run counter to your claim.

Can you point me to a scientific discussion somewhere that can describe the details of what you assert? It does not seem reasonable to me.
 
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I'm sorry, but I don't see how that could be true. Humidity is not a constant top (meaning to the top of the atmosphere) to bottom in the column of air; it's a local phenomenon, especially if you are in a building where it can be quite different from what it is outside. Absolute humidity doesn't determine the drying ability of air, either; relative humidity does, which is exactly what Light was saying. When you heat air which is at 10 degrees F to 75 degrees F, its absolute humidity does not change, but the relative humidity will drop from (possibly) 100% to very much less than that, putting your acoustic instruments at risk.

And are you saying that a barometer will register a change if you go outside a building that has a different relative humidity than ambient, even if it is not sealed? I can't see how that could be true; the pressure would equalize whenever you opened a door even if it were sealed. Furthermore, while it is true that wet air weighs more than dry air, days of high barometric pressure are frequently (usually, even) dry. That would seem to run counter to your claim.

Can you point me to a scientific discussion somewhere that can describe the details of what you assert? It does not seem reasonable to me.
I'll say again

I have not suggested that a barometer will measure humidity for you. I have always said it will give you an indication of the manner in which humidity and vapor pressure change in relation to seasonal changes, specifically in the British Isles.

Take a balloon and inflate it add say 2 grams of water. Measure how it behaves in relation to change in temp and (altitude). Do the same with dry air. Next burst the balloon and measure the same air in relation to it's pressure and specific humidity.

I never said that a barometer will give you an accurate measure of humidity. I have said that here you can more than reliably predict changes in humidity with one. People have done so for years and will continue to do so. More importantly I described it as a method of understanding how swift changes in humidity and temperature can take place in relation to seasonal changes and the meteorological phenomena that result. Here in the UK I can predict the humidity quite accurately just by observing which way barometric pressure is moving.
 
I'll say again



Take a balloon and inflate it add say 2 grams of water. Measure how it behaves in relation to change in temp and (altitude). Do the same with dry air. Next burst the balloon and measure the same air in relation to it's pressure and specific humidity.

To prove what, specifically?

I never said that a barometer will give you an accurate measure of humidity. I have said that here you can more than reliably predict changes in humidity with one. People have done so for years and will continue to do so. More importantly I described it as a method of understanding how swift changes in humidity and temperature can take place in relation to seasonal changes and the meteorological phenomena that result. Here in the UK I can predict the humidity quite accurately just by observing which way barometric pressure is moving.

Oh. OK, so you can watch a barometer and tell when a storm is coming. All right, but what was throwing me off the track was this passage:

"A lot will depend on what, where and how your store your guitars. Do you take em out lots? How long for? What guitars? Where you are in relation to the coast? Get a barometre and take a look at the difference inside and out over a period of time."

Inside and out of what? I read it as looking at the difference in barometric pressure between indoors and outdoors, and that doesn't make sense, obviously.
 
The point being that you can use a simple tool to help you understand how the prevailing climate in your areas changes and changes swiftly. You don't need to know what the humidity is just that it changes in relation to the season and quickly. This is the danger your guitar faces. A guitar will handle quite high relative humidity and also quite low humidity. It will not appreciate being thrust from one to the other in a short space of time. If the change is gradual it will cope much better. Thats not saying it's a good idea though. Maintaining a controlled environment is by far the better way to go.

If I rephrased the comment you just quoted I'd make that more clear. ;)

If you were to move your barometer outside to a cold wet climate from indoors in a dry heated environment, temperature would be the biggest factor in any change in the reading you get. Vapor pressure would be secound. Yes, that would indicate a need to recalibrate rather than a specific change in the atmospheric pressure.

Really I wish I'd just said check the detailed weather forecast frequently and examine how high an d low pressure are related to humidity in temperate climates rather than look at a barometer it would give you the same information just less graphically. :D

And yes if you want to know the actual relative humidity of a specific location a hydrometer is the best tool. I have several in the workshop. None are perfect. I always look to keep the changes gradual in any case as the extremes here are not that great.
 
If people were really that concerned with protecting their instruments from a change in humidity, they would never leave their house.

I guess the old timers never played a live gig or left their houses without a hygrometer.:rolleyes:

Much ado about nothing. Hell, I spray water inside my acoustics with a garden hose.

Of course, I use the fine spray attachment.;)
 
dang, all I use is a thermometer with two sides, one reads temp fareinheit and the other reads percent humidity...it cost me $5...
 
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