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View Full Version : Humidty Levels Don't Matter -- Mostly



OlderThanWillie
Apr-29-2004, 3:31pm
There's a lot of talk about maintaining the proper humidity level for your instruments when they are stored. There are tubes with sponges full of water, there are discs that fit in the soundhole, some put a cut apple or potato(e) in the case, etc. Some stores have special rooms with a controlled atmosphere for their acoustic instruments.

Here's my question -- if humidity is so important, why are so many of the vintage instruments (some are 90 years old) in very good to excellent condition with no cracks or repairs when they have been stored for many years under a bed or in a closet and sometimes in the attic?

Probably keeping them in the case tempers the speed of climate change as we move from summer to winter and allows them to expand or contract slowly. That being the case, why bother with all the products that supposedly maintain a high humidity environment? Those vintage instruments survived pretty well without the dampit -- at least 90% of them did.

We have a few repair gurus that follow this forum -- what do they have to say?

Big Joe
Apr-29-2004, 3:57pm
Hey OTW...Mostly you are right. Most people get concerned about the wrong things at the wrong times. Actually I've seen more damage due to use of humidifiers....especially those that fit into the instrument....than from those that do not use them. The real key is to use common sense. If you are going to play in a thunderstorm you are going to have too much humidity. Not much is going to help except getting it into a stable environment and keeping it there till it settles back. If you are in a desert you might need humidification, but for most people in most situations that is not the case. Some people who have gas heat in the winter and do not humidify the home may need a humidifier. An apple or potato(e) would do just as well as the expensive systems and could be actually safer for your instrument. The rule of thumb is if you are comfortable, your mandolin is. If you are not comfortable, your mandolin is not either.

Bob A
Apr-29-2004, 7:02pm
When the outside gets below freezing, there ain't much moisture left in the air. Then you heat the air, and the relative humidity goes down even further. Then things start to shrink. Maybe you'll be lucky. I'm a worrier, and I use a humidifier in the room where I keep the instruments, and I still had the back start to shrink on the F4 - had to get it re-glued, and a little slice of wood added behind the binding.

But hey, it's your instruments, not mine. Do what you think is best.

Bandersnatch Reverb
Apr-29-2004, 7:18pm
Bob,
I hate to correct, but when the outside air gets below freezing there is a lot of moisture in the air. Thats why you can see you breath. The air is saturated, and cannot hold the additional moisture from your exhalation. The same happens at a different temperature, in the bathroom as the shower steam clears. There is a point there where your breath can be seen, as the air has just gone from steamy (total saturation) to clear (near total saturation).

However, you're correct that the RH does go down when you turn the heat in your home on.

muzicfreak
Apr-29-2004, 8:30pm
Perfect I was just about to make a post about this... I live in Mesa,AZ so I'm in the middle of the desert... and i have been pretty concerned about keeping my mando nice and humidified.. My question is i saw in the classifieds for the Humistat humidifiers... Does anyone have any experience with these little puppies? Right now i use a little green snake.. but the thing dries out within a few hours... Any info would be great! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/mandosmiley.gif

OlderThanWillie
Apr-29-2004, 8:46pm
To the humidity guys -- explain why the old instruments are in such good shape after all the winters and summers under the bed.

BigJoe
Apr-29-2004, 9:47pm
Let me make a slight correction about heat drying the air in the winter. If you use gas heat rather than electric it will dry the air out much more. Here is why. Electric heat does not heat the air as much. Electric heat operates at about 120 degrees. It does not exceed that. Gas heat can be as much as 180 degrees though about 160 is probably the average. The extra fourty degrees the gas heat operates at dries the air faster and causes more problems. If you live in a relatively normal humidity area and the normal amount of moisture hits the air in the home from such things as showering, dish washing, clothes washing, plants, etc, the air will stay quite well humidified. If you use gas heat it is always adviseable to use a whole house humidifier to aid the entire structure. Wood does not like to be too dry. For example, if you notice the legs and braces on your chairs become loose, it is a result of a lack of humidity. The same goes for any kind of wood in your house including furniture, framework, doors, etc. By properly moisturizing your home you improve your life quality much more. The wheel type humidifiers designed for room use are not too good. They can actually cause more damage than good because they shoot raw water into the room. Raw water on wood or most other things is not good. Instead, something like a Honeywell steam humidifies that fits into your duct system and is automatically operated by a humidistat on your wall will give far better humidification. In addition, it will always give the right amount of humidity. The other kinds do not allow it to be properly adjusted to the right level of humidity. Anyway, that is a short course on the subject. The best thing is to live where you don't have to worry about it http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

Gavin Baird
Apr-29-2004, 10:10pm
Actually the use of gas to heat air or water in a house consumes the inside air for combustion of the gas. When this is done you have an exhaust of CO2, CO, and of course water vapor which used to be inside your house. Now you are going to experience a lower humidity unless you make up with a humidity mechanism...g

furashgf
Apr-29-2004, 10:14pm
Wait. I have one of those dampit things. Is it hurting my instrument?

Keith Newell
Apr-29-2004, 10:39pm
I lived in Alaska for a few years and my Family still does. When its gets cold almost everybody gets out the humidifiers for there homes because the air is so dry and its uncomfortable because of dry itchy skin and chapped lips.
#Keith Newell
http://www.newellmandolins.com

8ch(pl)
Apr-30-2004, 3:55am
For badersnatch reverb, the fog created by our breath is not in the air originally, it comes from our lungs, and we humans are a very moist environment.

I use a humidifier in winter. I had to get a 5 inch long crack repaired in the side of my Mid Missouri when I first got it. It was stored under the bed in a gig bag for 5 months. I also put a lungful of air inside the mandolin with a straw now and again.

Some woods are worse than others as well. I believe mahogany is less apt to crack than Rosewood.

cutbait2
Apr-30-2004, 6:29am
i live in Florida i purchased an instrument from a guy in New Mexico. i would check the tuning daily. it consistently went sharp for about 2-3 weeks. had i not been checking it the tension on the neck could have been damaging. also moving instruments to and from climates that do not use AC during summer requires caution. regarding the instruments under the bed for 40 years the strings have probably gone slack and certainly there are plenty of old instruments with cracks/structural problems that are rarely discussed.

sunburst
Apr-30-2004, 7:00am
To the humidity guys -- explain why the old instruments are in such good shape after all the winters and summers under the bed.
Luck.

Some percentage will be damaged and some percentage will not.
(do you feel lucky?)

I'm curious where the 90 percent statistic came from in the first post. My repair experience leads me to speculate otherwise. Obviously, as a repairman I see more damaged instruments than ones that survived in "perfect" condition, so that would make it seem to me that a lot of old instruments have been damaged by humidity changes.

Those instruments under the bed were not being played. If they had been being played, they would probobly have had problems with playability periodically when the humidity changed.

Those with flat sawn parts may be more susceptible to problems.

Guitars, with their cross-grained bracing are more likely to be damaged by humidity changes than mandolins.

All in all, it's sort of like smoking. Smoking causes lung cancer and heart disease, humidity changes cause instrument damage. The smoking statistics are well documented, the humidity statistics are not.

straight-a
Apr-30-2004, 11:50am
Here in NC the LAST thing you have to worry about is lack of humidity!!

green_leaf
Apr-30-2004, 2:29pm
I use a combination of gas furnace and wood stove, and got some serious dehydration in my mando stored in its case on the second floor. The tailpin got so loose it had zero traction, and just slid in and out freely. After rehumidifying, it's fine, and I use one of those spongy, obscene-looking humidifiers.
Nothing warms you like wood, but it will suck the moisture right out of your house.

Chris Baird
Apr-30-2004, 2:53pm
It is humidity change that hurts mandolins. #A mandolin can acclimatize to a wide variety of stable humidities. #When considering using humidification or dehumidification consider using it to create a more stable environment for you mandolin. #If your normal environment is consistently 20% or 75% it would be a poor decision (IMO) to store it at 50%. #Calculate your average RH and make an effort to keep your mandolin at that level. #It takes a very low consistent humidity to harm an instrument (below 10% could cause glue to lose its cohesive properties especially with the wood's different expansion characteristics pulling on things).

sailaway
May-01-2004, 5:32am
I have to tell you that I never paid too much attention to the humidity stuff over the years. I had 2 1960's Martin guitars (1 a 6 string 1 a 12 string.) I moved from an cabin with woodstove heat (1976) to an old house with hot - water radiator heat (1981) -- no problems for the instruments. Then moved to a house with new furnace forced air gas heat. (1992). within 6 months BOTH of the Martins developed serious cracks (12 string - a 'pickguard' crack, the other a more serious internal crack of the top cross braces.) Cost a lot of $$$ to fix, so I am VERY careful now to add extra humidity to all the instrument cases with the various canister humidifiers that fit inside the cases. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/mad.gif

sailaway
May-01-2004, 5:32am
I have to tell you that I never paid too much attention to the humidity stuff over the years. I had 2 1960's Martin guitars (1 a 6 string 1 a 12 string.) I moved from an cabin with woodstove heat (1976) to an old house with hot - water radiator heat (1981) -- no problems for the instruments. Then moved to a house with new furnace forced air gas heat. (1992). within 6 months BOTH of the Martins developed serious cracks (12 string - a 'pickguard' crack, the other a more serious internal crack of the top cross braces.) Cost a lot of $$$ to fix, so I am VERY careful now to add extra humidity to all the instrument cases with the various canister humidifiers that fit inside the cases. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/mad.gif

mandorado
May-01-2004, 7:17am
I think this is probably more of a concern if you travel a lot, or ship your instrument often ... like if you live in S.F. CA and travel to CO for a gig. I've heard nightmare stories about instruments going way out of wack when subjected to travel to different climates (If they are shipped ... keep and eye on them or help them adjust ... especially in winter!).
I think this question get's asked a lot nowadays because people are buying instruments and having them shipped from one part of the country to another [climate], back and forth, etc. ... much more often than the "old days", when you bought an instrument at your local music store. I think shipping can be very hard on instruments (again, especially in winter).
Come to think of it ... in the "old days" most people didn't travel as often or as far away from home as they do now. May be why some of those old instruments are still in good shape.
If your instruments are not traveling, and are doing ok, I don't think you need to stuff a hose in them. Use some common sense when it comes to storage and where they are placed in you home, and they should be fine.
My 2cents. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/coffee.gif

Ken
May-01-2004, 10:05am
I like the common sense approach. I don't like worrying excessively about my mandolins, they are tools to be used, not pieces of art to be kept in a vault (although they sure can be pieces of art too) I still often keep one in my van, under a blanket, under the rear seat, and have never had problems, winter or summer, in doing so. But to also weigh in on the other side, several years ago in the winter, I was keeping a mandolin at work where the heat was kept a lot higher than what I keep it at home, and ended up with a crack from the back of the oval soundhole all the way back to to the tail block. The crack was wide enough that I ended up putting a spline in. So, anyhow, I guess my rule of thumb is don't worry too much, but don't completely ignore your mandolin's surroundings either. That sounds like common sense, doesn't it?
Ken

peterbc
May-01-2004, 10:25am
Bandersnatch,
I think that there is less moisture in the cold air because the saturation point changes with temperature: ie, cold air has a lower capacity to hold moisture than warm air does. So while it may be saturated when you exhale in the cold or when you take a hot shower, the moisture levels are still different.

peter

Ken
May-01-2004, 6:23pm
peterbc you are correct, cold air holds less moisture than warm air, hence fog, when the warm air full of moisture hits the cold ground, it loses heat and can't hold as much moisture so it condenses out as fog. Same idea as those water droplets on your bottle of cold beer or glass of iced tea (your choice) on a hot summer day.
Ken

grsnovi
May-01-2004, 8:59pm
Suppose you cut down and slabbed a bunch of spruce and stacked it outside to air dry for ten years.

Would you expect the moisture content of the wood to be the same if you had done this in the rain forest of Brazil vs. the desert of Saudi Arabia?

Wood will reach an equilibrated state with the air around it.

If the wood is finished on one side and not the other it will equilibrate differently than an unfinished piece.

A case creates an environment that will change the rate of equilibration with the "outside" air, so an instrument in a case will react to humidity changes more slowly than one sitting out.

An instrument that was built in a high humidity environment and then parked in front of a hot air vent in a heated home in the winter (low humidity) is going to likely have problems. Same would be true in reverse.

Joe's advise in his first post: "if you are comfortable your instrument will be" generally holds true.

We've all probably had instruments adjust with the seasonal changes.

I think the question of why a 90 year old or 70 year old instrument is "fine" has to do with the fact that over all of those years, the moisture of the instrument has come to a very nearly perfect balance with its location. The varnish crackle on those instruments has a lot to do with the constant flexing of the wood over the years due to humidity.

John Ritchhart
May-02-2004, 1:00am
I maintain my house humidity at 62.573% relative humidity which exactly replicates the ambient environment in the barber shop where BILL bought his Loar. Once it got down to 62.0% and my house cracked.

Bob DeVellis
May-02-2004, 10:02am
As for old instruments not being affected by hunidity over the years, what are the facts? I've seen plenty of old instruments where the back or top has pulled away from the rims. Reading descriptions of old instruments where the seller describes "professionally repaired cracks" seems pretty common, too. Just visit a few vintage websites and read the ads. Loose braces are also a fairly common malady as an arched top tries to become a flat top in response to low-humidity shrinkage. Also, remember that there is a certain amount of "natural selection" going on here. The instruments that split like a ripe watermelon because they were put on the mantle above the fireplace have mostly been junked. The ones still with us are those that somebody considered in good enough condition to be worth saving.

It's my understanding that you see your breath on a cold day because the moisture from your lungs is immediately condensed by the temperature change, not because the air is saturated. If the air is saturated, you've got fog or precipitation. I've experienced many a dry, cloudless day when my breath could be seen. The moisture in the air can vary both when the air is warm and the air is cold. Either warm or cold air can be saturated or relatively dry. But that moisture will precipitate out (turn from vapor to droplets of liquid water or crystals of ice) a lot sooner in cold air. That's why we talk relative humidity and not just humidity.

Wood undeniably changes size as a function of humidity. In fact, I have a wood book that urges craftspeople to build a simple humidity gauge for their shops by putting together blocks of wood and attaching a pivoting pointer to one end. As humidity changes, the swelling and shrinking causes the pointer to pivot. This is intended by the book's author as a vivid reminder for woodworkers for how much wood expands and contracts in response to humidity -- even when the changes aren't that noticeable from changes in comfort level.

Clearly changes in humidity are worse than steady humidity that's either too high or low. But it can be difficult to recognize when the humidity is changing significantly. I live in North Carolina and some internal environments have surprisingly low humidity in the summer when air conditioning is run agressively. Those environments feel comfortable, after having walked around in the hot, steamy, outside air. But measure the actual humidity and it can be 25% or so. Play your instrument in that setting each day and then drag it out to a festival and leave it in the exposed, humid air, and that represents quite a change.

Yes, there are old instruments that are doing fine. There are people who smoke and live to 90. There are cars that go for years without an oil change and seem to be doing fine. There are even people whose parachutes don't open who live to tell about it. But why gamble? It's probably not necessary to be obsessive about an instrument that may not develop problems and that, if it did, could be easily replaced. But why risk "jumping without a parachute" when you're dealing with a truly treasured instrument?