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bdisp
Jan-21-2005, 5:48am
I have one of Gerald Anderson's F-5 mandos. I am currently using the long "tube" shaped humidifiers carefully slipped thru one of the f-holes. It has a sponge inside and holes on the outer rubber tube. It makes me nervous every time I remove it. What do you use?

I am told wooden instruments will absorb the moisture they need as they are stored in their cases with a humidifier. Then they won't absorb any more. I'd like to hear other opinions on this.

twaaang
Jan-21-2005, 9:18am
I have one of those green tube thingies for both my f-hole and my oval hole mandos, and have no qualms using them other than trying to keep them away from the manufacturers' stickers inside the instruments, lest they cause the ink to run. (Since I used to work in urology, other associations come to mind but, oh well, never mind that!)

Each of these came with a humidity indicator card intended for keeping in the room where you store the instruments. I actually keep this in the instrument case as well, as a result of which I learned two nights ago just how dry the church basement is where I play a weekly session (I had left the case open while playing, and some very vivid colors emerged on the indicator.)

Since I live in Vermont and dryness is the prevailing issue, I also keep a second moisture source "at large" in each case. I just cut some sponge and keep it in a perforated aspirin jar, with the top left off. Very cheap, and so far so good. -- Paul

Dennis Schubert
Jan-21-2005, 9:31am
I've used half a potato in my case during the winter months, as an organic humidifier. No Irish jokes, please.

glauber
Jan-21-2005, 9:52am
If you use the "dampit" right, it doesn't leak. I soak mine in filtered water for 30 seconds or more, then roll it in a towel and "pat dry". There should be no moisture on the outside the tube when you stick it in the instrument. The sponge inside will store a small amount of water, and release it slowly by evaporation.

Greg H.
Jan-21-2005, 11:20am
bdisp,

Where you live I would strongly question the need to further humidify your mandolin. I live around 30 miles west of you and found that I had inadvertantly over humidified my mandolin causing the neck to swell. Get a hygrometer and check the humitity level in your house (or whereever you're keeping the mandolin) before you increase the mandolin's humidity level. If the humidity is over 50% you probably don't need to do anything.

Ken Sager
Jan-21-2005, 11:29am
Here's a cool thread about this.

Previous Thread (http://www.mandolincafe.net/cgi-bin/ikonboard.cgi?act=ST;f=8;t=12704;hl=stat.com)

I bought a couple hygrometers & humidifiers from http://www.humistat.com/ and love them.

Even though I live in the desert (Utah) my hygrometer is always between 45-60, which is well within my comfort zone, so I haven't needed to add water.

Best,
Ken

bdisp
Jan-21-2005, 12:35pm
I guess this means the instrument WILL keep absorbing humidity. Not seek it's ideal humidity level and stop.

Lee
Jan-21-2005, 12:46pm
I had a Flatiron bazouki that self-destructed from the Philly-area summertime humidity. So I can say from experience that it is possible to over-humidify. #I just bought a 3-1/2 gallon unit made by Hunter from Sears Hardware; $69.00. #I have a large mulit-level floor plan and it's been keeping 45% consistantly running on "low". Also makes the house more comfortable. #This particular brand uses no filter; they ain't cheap to replace. So far I like it.

glauber
Jan-21-2005, 1:05pm
I guess this means the instrument WILL keep absorbing humidity. Not seek it's ideal humidity level and stop.
That's probably right (i'm not an expert on woods). I'd think the rate of absorption should slow down as the wood gets saturated.

There are substances that tend to regulate RH, i.e., absorb humidity when the RH is over some threshold, and release humidity when it's lower. You can usually find this stuff in places that sell to cigar affictionados. E.g. http://www.cheaphumidors.com (no affiliation, but i've bought stuff from them a couple of times). I use a couple of their DryMistat tubes (http://www.cheaphumidors.com/Merchant2/merchant.mv?screen=PROD&Store_code=ch&Product_code=HT101&category_code=humidifiers) for my wooden flutes, because they take tap water (no fancy chemicals).

But note that cigar products are designed to keep RH around 70%, which is fine for flutes but could be too high for mandolins. In practice, during the dry months, it's hard for me to keep RH even at 50% inside the small cigar humidor i use for my wooden flutes.

g

John Flynn
Jan-21-2005, 1:14pm
I have tried many of the commercial products. What has worked best for me, according to my in-case, calibrated, digital hygrometer is the following: I took a plastic soap case, like you would use to take a bar of soap on a camping trip. I drilled about 20 holes in the top. I cut a piece of sponge to fit. I keep the sponge damp, but not wet, with tap water. As it happens, the one I have wedges perfectly into a nook in my case. It will keep the inside of the case at about 50% RH when the room is at 30% and it lasts a long time between "dampenings."

glauber
Jan-21-2005, 1:15pm
As an aside, i seem to have more trouble than most people keeping the RH in the house high... Right now in January and February, if i can get it to 40% i consider it a major gain. Some days it dips to 30% (but at least doesn't go lower than that). I have an "Aprilaire" brand furnace humidifier. I tried standalone humidifiers too, but found out that anything that would give me good results would require loading it by hand with many gallons of water per day, to affect the whole house.

glauber
Jan-21-2005, 1:19pm
As another aside, it's probably paranoia, but if you have a humidifier in the instrument case, how can you be sure the humidity is being spread evenly, instead of being all absorbed by the portions of the instrument that are closest to it?

Lee
Jan-21-2005, 2:08pm
Yes Glauber, I have the same concern about Dampits. What prevents them from over humidifying?

glauber
Jan-21-2005, 2:47pm
Yes Glauber, I have the same concern about Dampits. What prevents them from over humidifying?
Nothing. Only you. These devices require careful watching. I do believe that in a dry climate, it's hard to over-humidify, but it's not hard at all if the air is already damp. I think damage by mould is even easier to achieve than damage by over-absorption of moisture. I've had mould in one of my flutes, and it's not pleasant or easy to get rid of.

To be honest, i'm not comfortable with any of these solutions. I think if you have a hardshell case, an in-case humidifier placed so it doesn't touch the instrument (maybe under the arm) is probably the best option. But i don't, i only have gig bags for my 2 mandolins. I'm thinking of buying a big plastic storage tub (which should be mostly airtight when closed) and putting the instruments, some humidifiers and a hygrometer inside. Still requires watching, though.

By the way, are you getting 45% throughout your home, with that single Hunter humidifier? And how long does the water tank last?

Lee
Jan-21-2005, 2:51pm
I'd go with the 3.5Gal Hunter unit I bought before using a large plastic tub. That sounds scary. Plus it could be a shock for them if you pull them out of the tub into a bone dry room.

John Flynn
Jan-21-2005, 3:13pm
...if you have a humidifier in the instrument case, how can you be sure the humidity is being spread evenly, instead of being all absorbed by the portions of the instrument that are closest to it?
OK, I am no "Mister Science" here, but I have read a lot about the instrument humidity problem and done some experimentation with humidfiers and hygrometers. Given enough time, like 6 hours or less, in a small closed space like a case, humidity permeates all the air in that space. So if you put a humidifier near the head of an instrument, overnight the air in the case will become all one RH%. Now I don't know about the short-term spread of humidity, like what happens over, say, just an hour in the case, but with humidity, I think you are more concerned with long term effects. Also, what is great about having a humidfier in the case is that the case itself seems to absorb humidity. I have taken my humdifiers out of a case and had it still hold humidity for a day or more.

As far as over-humidifying, I have never been able to do it with case humidfiers during the low humdity season. I can load my case up with every humidfier I have, leave it for a week when I travel and the case will never get over 55%, which is acceptable. I know that you can get damage from too much humidity in tropical areas, but that is a different scenario.

MWM
Jan-21-2005, 4:03pm
I use the 35mm film canister method. It's drilled with about 100 small holes on the side and contains a sponge. I dampen the sponge every 2-3 days and it works well. It fits absolutely perfect under the neck next to the body in my hardcase. My endpin used to come loose in the winter months but never does any more. I've been using this for several years since someone here recommended it. It's a great & inexpensive solution.

bdisp
Jan-21-2005, 5:01pm
So if the hygrometer is in the case, how do I know the RH inside the mando/(insert other wooden instrument here)? Is it safe to assume it's all the same RH. It's the inside of the instrument that needs to be humidified........right???

glauber
Jan-21-2005, 5:32pm
I'd go with the 3.5Gal Hunter unit I bought before using a large plastic tub.
You did! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

How long does the water in the tank last?

I've read good things about the Hunters, specifically, that you only have to clean them up once a week instead of every day.

Dolamon
Jan-21-2005, 7:34pm
Bdisp - If you leave the humidifier in the case - the humidified air will migrate to the drier interior. If it still worries you, exhale into the instrument with pursed lips ... exhaled breath is normally about 70 to 73% relative humidity. This will guarantee there is a level of humidity - at a higher temperature for at least a few moments. As the temperature drops, the humidity will 'condense' (sort of) on the cooler interior surface of the instrument. It works for me - I am constantly checking any of my upstairs instruments and finding some of them will need refreshing daily, some every three days.

It seems - once you have a normalized environment in a case for a week or a month or so, you won't be required to fill the humidifier every day.

earthsave
Jan-22-2005, 9:29am
Definitely get yourself a decent digital hyrgrometer for your case. If you are paranoid, check it every so ofter. If you are playing you mando daily, which means opening the case, I dont see how you could possibly over humidify. If you are storing, check it daily until you are satisfied that you are not over humidifying it. Then you can check it less oftern.

acousticphd
Jan-22-2005, 4:32pm
I've tried various store-bought and homemade humidifiers both in the case or in the house that seemed to work fine. I used to use pieces of sponge in ziplock bags with holes poked in them, similar to the soap container or film can method. What is important is to have a good humidity meter and check the levels in your cases to see how well and how long the humidifier works.

Now I live in middle TN and for half the year I keep envelopes of dessicant in my cases to try to prevent excess humidity.

Here's another question; let's say you put away an instrument in a good hsc at 40-50% RH. The instrument remains cased for a long time while you play other instruments. Yes, it's sad but it happens. Even if your house stays at a safe RH, should the cased instruments be "refreshed" from time to time due to using up the moisture in the closed case?

bdisp
Jan-22-2005, 4:54pm
I have purchased (awaiting delivery) 4 hygrometers from humiststat.com mentioned above. I think the key is to monitor regularly. My ol' D-18 I had from the 60s thru the early 90s ain't seen the 1st hydro meter of any kind. I doubt any of us did.

morgan
Jan-22-2005, 8:58pm
I live in north-central massachusetts, heat with wood, and according to my cheapo radio shack hygrometer the humidity is typically about 22-25% in mid-winter. I used to use the tube-type humidifiers but this year switched to film canisters with sponge, which last easily twice as long without re-filling. The same hygrometer says that both approaches typically add about 20% humidity to the case. I have a Damp-Chasser humidity control on my piano that strives to keep humidity at something like 42% - so I assume that the mid-40s that I get with this low-tech method is good.

Philip Halcomb
Jan-23-2005, 6:58am
One sign of over humidification is that your strings will appear to get higher. The humidity here dropped in October so I started using the dampit. Then I noticed the strings were getting higher and I was running out of room to lower my bridge. Apparently the top was swelling and pushing the bridge up. I stopped using the dampit and went to the humistat. Anyway after taking all the humidity away for a couple of weeks the top came down to about where it should be and the problem corrected itself. So after summer it's probably a good idea to wait a couple of months before starting the humidifying thing.

sunburst
Jan-23-2005, 8:59am
Threads like this show up from time to time.
In the book Understanding Wood by R. Bruce Hoadly, there is a whole chapter on moisture and wood. It's a book I often recomend to anyone who does anything with wood.
Anyway, there is a graph printed in the book plotting equilibrium moisture content of spruce against relative humidity. In the text are these words: "Reproduce this graph and hang it on your shop wall. Look at it every day. It's that important."

So...I took the liberty of reproducing it (rather crudely) and hanging it on the mandolion cafe.

Greg H.
Jan-23-2005, 1:22pm
Bdisp,

Because we're in the same part of the country I'm assuming that the humidity level in your house is somewhat similar to mine (of course there could be a good bit of difference between method of heating, number of indoor plants--these contribute a great deal--and degree of insulation). Mine generally runs higher than 70% in moderate temps. and right now (with the temp at 30 and the wind chill at 18) it's running at 50%. At these levels I have ceased to use any form of humidification at all unless I'm going to a dryer climate (in which case the film container with sponge seems to work quite well).

bdisp
Jan-23-2005, 1:49pm
I'm in central NC just south of Raleigh. Right now it's 26.8f/41%rh outside. Inside I'm @ 69f and 38%rh. Yeah......I know....I need a humidifier inside the house. I've learned that much from this thread.

Thanks for all the info folks. This topic has gone much farther than I thought it would. Very enlightening.

BTW, did I mention I hope to cure my M.A.S. this week.....

Greg H.
Jan-23-2005, 1:55pm
Ok, there's there's a fair difference between the humidity in our houses. I'm In Pittsboro about 20 miles west of you so I suspect my wife's affection for house plants is making up a good bit of the difference. (That might be another option, a good bit more attractive than humidifiers but require more maintenance).

And on to the more fun topic, Whatcha lookin' at? MAS is never cured, it's only put in remission. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif

Amandalyn
Jan-24-2005, 9:18pm
Check out this humidifier/hygrometer system. I offered this on Mandolin Cafe classified, but Scott took it off, because it was not "mandolin specific". With all due respect to Scott, some things (like picks) are for many instruments. I also realize this post is self promotion, but #as a mandolin player myself, I'm just trying to promote things that I feel are useful for the craft.( Kaufman does it here too!) Anyway, here's a link to the John Pearse website that has all the info on the humidifier, http://jpstrings.com/ksaire.htm
then if you are interested contact me for a special price
info@musicgrowshere.com
Teri/ The Music Tree

Lee
Jan-25-2005, 12:10pm
My house is a typical suburban multi-level. Living room/dining room and kitchen on one level above a crawl space, and the family room is three-steps down onto the slab with steps leading from the kitchen on one end and from the living room at the other. #Three bedrooms and bath 10-steps upstairs. I keep a circulating fan running non-stop and achieve good circular air-flow throughout the entire downstairs area. #I run the Hunter on Max. #I'd say it churns out 3-gallons a day and just manages to keep it between 35%-45%. #If I'm opening and closing the front door alot it takes a long time to get it back up. #But I found if I boil a pot of water on the stove that boosts it up quite quickly and then the Hunter can maintain it. #I didn't realize it had to be cleaned periodically. I'll have to actually read the instructions. Duh.

glauber
Jan-25-2005, 2:10pm
Thanks!

I think the cleaning part is more important for people who are running humidifiers because of allergy problems, but it's probably worth checking out anyway.

ira
Jan-26-2005, 8:24am
hey all of you aspirin bottle, film cannister humidifying types. i like the idea of this, but want to get it right (i must have 50 plastic film cannisters used for crafts with students).
so,
1,are the holes made all around the cannister/how big/how many?
2. how wet do you make the sponge, and how do you get rid of the excess moisture before placement in the cannister?
3. do you have a wad of sponge that jams into the cannister (i.e., fills it totally)>
4. do you put cover on the cannister or leave open?
5. where should i put it? i have a coffin case- pretty tight? if it should go in the space near the neck, should i get some tape/velcro to hold it in place or do you just leave it loose?

thanks for all of your help in this matter.
peace,
ira

gnelson651
Jan-26-2005, 8:50am
Instead of using a sponge, buy yourself (or your spouse) some flowers and pull out that green spongy stuff they use to keep the flowers fresh. It absorbs about 20% of its weight in water and will last longer than a sponge. As before, put this green stuff in a film can, plastic soap dish, etc.

ira
Jan-26-2005, 3:40pm
thanks for the suggestion gnelson-guess i'll kill 2 birds with one stone (humidify and get points with the wife), though whether flower stuff or regular sponge, i;m still not sure how wet it should be , etc....(see posting above)

Lee
Jan-26-2005, 4:06pm
I don't understand the graph. What is "Equilibrium Moisture Content"? What is the significance that it stops at 32%? Percent of what? What is the graph telling me?

sunburst
Jan-26-2005, 4:29pm
See? Everybody should read that book! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

The % moisture is by weight. In other words, if a piece of wood is at 32% moisture content, 32% of the weight of that piece of wood is water.

At a given level of relative humidity, wood will either take on moisture, or give up moisture to the air, until it stabilizes at the equilibrium moisture content for that level of relative humidity.

The 32% is beyond the fiber saturation point for spruce. In other words, where the curve stops is all the water spruce can absorb unless you submerge it in water, so the graph doesn't need to go beyond 32%

So, what the graph shows is how much moisture will be in the wood in your mandolin if it's kept at a given relative humidity.
Wood should be kept between 6% and 8% moisture. If it varies much, it moves. In other words, it shrinks when it's dry, and swells when it's wet. That movement puts stress on the wood and the glue joints and can cause damage, or make the instrument more succeptible to damage.

glauber
Jan-26-2005, 11:53pm
Wood should be kept between 6% and 8% moisture.
Ah, that's the important thing you forgot to say! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif

It all makes sense now. Do you have a graph for mahogamy too?

How about laminate (plywood)?

sunburst
Jan-27-2005, 8:29am
Other woods, like mahogany, will have similar curves. The graph in the book shows a range that gets wider as you go toward the right of the graph. Spruce was chosen because it is a representative species. The differences are mostly the weight of the wood. A heavier wood will have a little less % moisture content because the wood is heavier, so the same amount of water will be less of the weight as a percentage.

Plywood is restricted in it's movement because of the cross-grain laminations, so, even though is does take on and loose moisture in responce to the environment, wood movement and it's associated problems are less. The graph wasn't intended for plywood.

Lee
Jan-27-2005, 9:38am
Thanks Sunburst. I understand now. (I wonder if I was the only one who had the guts to admit I was mystified?)
I do know a bit about wood from mypiano tuning experience. Some piano's are being made with laminated soundboards. They are not excellent sounding, but they often carry lifetime guarantees against splitting and are extremely resistant to humidity problems. (addressing Glaubers question).

R. Kane
Jan-27-2005, 12:02pm
The green spongy stuff is called Oasis, and it can be purchased at a flower shop. I believe its the same stuff as inside the planet waves devices.

glauber
Jan-27-2005, 4:37pm
Wood should be kept between 6% and 8% moisture.
So for spruce, that would be between 30% and 45% RH (air), with 45% being on the wet side. Most time when we discuss this subject we treat it as if 45% were on the dry side.

sunburst
Jan-27-2005, 10:30pm
We're talking ideal conditions here. One of the things I learned from that graph was how hard it is, practically, to keep wooden things in the ideal range, especially if it's something you carry around in a case and play music on in all sorts of situations.
Actually, if you can stay between 30% and a little over 50% relative humidity most of the time, you're doing well, and you can bet it'll be outside that range from time to time.

Amandalyn
Jan-29-2005, 3:58pm
Ok, for you guys who are not familiar with the "Green Spongy Stuff" -OASIS. My other profession is a floral designer, so if you're gonna use oasis here's some tips. It can "leak" if over saturated.
If used before in a floral, it can become moldy- watch it.
It also can crumble if used before.
Otherwise I would say it's a good alternative to a sponge- just remember to use a hygrometer with anything to check your humidity level,
The Flower Child. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

Greydog
Jan-31-2005, 3:03pm
At the Podium, one of the local guitar shops in Minneapolis, Marty Reynolds (repair specialist) showed me how to make a cheap humidifier. He has directions posted on their website.www.thepodium.com (http://www.thepodium.com/instcare3.html)

Andy Morton
Jan-31-2005, 3:49pm
You can buy a decent hygrometer from sears---made by holmes. Cost about 5 bucks. I have several and you can measure accuracy using the "salt test." The were very accurate (within 5%). To do the salt test--put hyrgometer in zip lock bag and a bottle cap filled with moistened salt. After 6 hours the hygrometer should read 75% exactly.

Andy Morton

Salty Dog
Feb-02-2005, 2:54pm
I'm using a Planet Waves humidity and temperature sensor and a Planet Waves SMALL instrument humidifier, both purchased from Elderly. #They seem to be working well.