Humidify. Do I have to?

[johna2u]

I bought the guitar on the left on a blazing hot day at a local swap meet. It was baking in the direct sun. It is a 1972 Harmony Sovereign H6303, Solid spruce top and Solid mahogany back and sides. Not one crack on that thing. Inexplicably the Sovereign Head-stock laminate was missing when I got it(I put a curly teak veneer on the headstock. Looks cool.). It could use a neck reset, but other than that this guitar is near pristine.

The other guitar is a 70's era MIJ Martin copy. It looks and plays like brand new. Both have been hanging on my wall for year and years and years and... well you know.

Recently I bought a Taylor 414ce Great sounding guitar and I love it but it had cracks all over it. It must have ridden around in the back of a pick up truck in Tucson for a few summers I am guessing.

Anyway, I want to see my guitars. I want them hanging like ripe fruit begging to be picked. I don't want to keep them in a case in the closet with a humidifier. Do I really have too?

By the way I live near Sacramento California, do not have central heat or air. In the summer we run the swamp cooler and in the winter we sit outside in the hot tub and cuddle. (of course we have a hot tub. We are in California!)

[charles Tauber]

Originally Posted by johna2u

Do I really have too?

If you don't mind the risk of cracking, no you don't have to.

Start by knowing, rather than guessing, what the actual room humidity is. Buy an inexpensive hygrometer and read the actual room humidifier. Ideal is in the 40% or so range, assuming the instruments where made/assembled in that range. The lower you get, the greater the risk of cracking. You chose your risk tolerance. In the 40's, little risk of cracking; in the 30's increased chance of cracking; in the 20's fairly likely to crack; in the 10's almost certain to crack.

Destructive testing is one approach to eliminate uncertainty: just reduce the humidity until one or more cracks, then raise it a bit.

There is also the issue of braces/glue joints loosening at low humidities and the changes in geometry that result from the wood shrinking.

[johna2u]

Ok I guess I have been lucky so far. I will buy a humidity gauge. I bought a damp it humidifier that came with a humidity reading card. Cannot for the life of me figure that thing out.

I am bringing my Taylor back to life and don't want it to crack again. It is an awesome guitar.

[fazool]

The way I've always viewed it is like insurance.

Without proper humidification, a guitar probably has a 90% chance of surviving, but that means one-in-ten might crack over its lifetime.

With proper humidification, I would bet a guitar has a 99% chance of surviving, meaning even with humidification one-in-one-hundred will still crack.

Make up your own numbers, but those illustrate my philosophy.

[RayCJ]

Please be apprised that the inexpensive humidity meters (hygrometers) costing between $5 and $15 are a huge gamble in terms of accuracy. You'll be lucky if they're within +/- 7% and I've personally observed that some are off way more than that.

I finally settled on one similar to this which I verified using a wet-bulb measurement technique, to read within a couple percent. http://www.ebay.com/itm/Temperature-...oAAOSweuxWRXcz

Measuring by the wet bulb technique is a slow, inconvenient method -albeit accurate.

Once you have a meter you trust, you throw-out all the junky ones that are way off. I don't stress-out over keeping the humidity perfect but, make a little effort to make sure things are somewhere between 40 and 50% humidity. Not only to I have guitars but, I have a grand piano and some fairly nice art-work that should be properly maintained.

Ray

[Ned Milburn]

To the OP...

After you verify your RH, if you determine you should be humidifying, get yourself some Kyser soundhole humidifiers. They are the only ones that are effective for outside-the-case body humidification. They will NOT humidify the fingerboard, so if your humidity is indeed low, you may find you have fret ends poking out a bit. These can be rectified by a quick filing/polishing operation.

@ Ray... FWIW, I purchased 5 different "el cheapo" hygrometers from Amazon and tested them with Boveda's kit. They all came within 2 points of each other and are well within a functional margin of error.

The mechanical (analog) spiral spring style hygrometers are fine, too, since they can be easily set to the target humidity. Even if their calibration is off (not the setting at target RH, but the calibration of increments), these will provide the information needed to tell if you are near the target humidity.

Although instruments tend to be built near 40%, a comfortable keeping range for RH can be anywhere from 40 to 55%. I usually suggest 50%+-, since the guitar's wood WILL dry and shrink somewhat over the years, and a bit more humidity is better than a bit too little humidity. The guitar is built with expansion joints. Less than 40% and you get into crack territory.

[SteveS]

Wood acoustic guitars should be in a controlled environments with an RH of 40 to 50%.

The relative humidity in Sacramento typically ranges from 26% to 97% over the course of the year, occasionally dropping below 15% and reaching as high as 100%.

The air is driest around September 1, at which time the relative humidity drops below 32% three days out of four; it is most humid around January 3, exceeding 95% (very humid) three days out of four.

Yes - You do need to control humidity in Sacramento. RH swings of that magnitude are a problem for nice guitars.

If you do not want to bother with all that, buy a CF guitar.

[RayCJ]

Originally Posted by Ned Milburn

@ Ray... FWIW, I purchased 5 different "el cheapo" hygrometers from Amazon and tested them with Boveda's kit. They all came within 2 points of each other and are well within a functional margin of error.

.

Hi Ned...

I think we all agree that basic observation of humidity is necessary and that most folks settle in a range of 40 to 55%.

If you know of a particular brand of the "el-cheapo" ones that are reasonable, please let me know. I bought two, 4-packs of the Ambient Weather brand and 3 of the 8 units were more than 15% off. The remaining 6 were within a few percent. Later on, I purchased 3 from AcuRite. Two were off by 20+% and one was off by 15%. All the units sat for a full 24 hours right next to each other.

Given the uncertainty, I purchased the slightly more expensive unit and also did a wet-bulb measurement and can verify that 6 of my el-cheapo units are all within 5% which is close enough for me. At a cost of $36, the AcuRites went right in the garbage can. Upon looking at the reviews from the online retailers, it looks to me that about 1/3 of the folks complain about poor accuracy with these things even though many of the products get an overall 4 star review.

Ray

[Ned Milburn]

Originally Posted by RayCJ

If you know of a particular brand of the "el-cheapo" ones that are reasonable, please let me know. I bought two, 4-packs of the Ambient Weather brand and 3 of the 8 units were more than 15% off. The remaining 6 were within a few percent. Later on, I purchased 3 from AcuRite. Two were off by 20+% and one was off by 15%. All the units sat for a full 24 hours right next to each other.

Crapola!! You had bad luck with your hygrometers!!

I just used Amazon and ordered 5 or 6 different cheap ones, from about 8 bucks to 12 or 13 bucks a piece.

Oh, and the old mechanical spring style, I got them at the dollar store!! ;-)

I got these:

http://www.amazon.com/Crosse-Technol...rds=hygrometer

http://www.amazon.com/BlingKingdom-D...grometer&psc=1

http://www.amazon.com/JETTINGBUY-The...rds=hygrometer

[pops]

I prefer to humidify the whole house, not just instruments. I helps the cabinets, furniture, the house, your nose, wood floors if you have them will develop less squeaks. A house and everything in it is probably worth more than most peoples instruments yet they only humidify the instrument. Humidifying the house is not expensive and I feel less hassle than a humidifier in each instrument that should be filled every day or so.

[johna2u]

Well it looks like the first thing I should do is test the humidity in my house. Then hopefully I can get by with sound hole cover type humidifiers.

As I mentioned in my OP I don't have central heat or air. We use a swamp cooler in the summer which blasts the house with cool refreshing humidified air. Feels like an ocean breeze when you stand in front of it,

In the winter we do run the heaters for a few hours in the morning and evening but Sacramento does not get that cold usually. It never snows.

None of my instruments have cracked or have fingerboard shrinkage. I have lived in this house for 26 years.

The reason I have sudden concern is my recent purchase of a Taylor 414ce. It had about 5 repaired cracks on the back and one small one on the front when I bought it. (Craigslist special.) I've never owned a new guitar in my life! Well other than the Mosrite I bought when I was 18.

[Quickstep192]

Ned,

I'm glad you've had luck with el cheapo hygrometers. After reading positive reviews on amazon, I bought one of the top reviewed hygrometers. It wasn't just inaccurate, it wasn't even close. It's measuring humidity at the landfill now.

(actually, it's not really measuring humidity in the landfill, I removed the batteries before I tossed it, so the batteries wouldn't end up in the landfill

[pops]

I think a mechanical gauge would be more accurate than and electric. I have a couple I have had for decades and unless they're both off the same still work fine.

[RayCJ]

Originally Posted by pops

I think a mechanical gauge would be more accurate than and electric. I have a couple I have had for decades and unless they're both off the same still work fine.

It all depends on the quality of the gauge. Mechanical units work by way of strands of hairs or various fibers that expand and contract when they absorb moisture. Sometimes they use coiled steel bands with a hygroscopic coating on one side. Depending on how much moisture is in the coating , it causes the bands to curl differently. Over time, all of these can lose their flexibility.

Most of the electric units have an exposed porous semi-conductor. As it absorbs moisture, it's electrical conductivity changes and from that, humidity can be comparatively measured.

Electronic or mechanical units show approximations of actual humidity with higher quality units doing a better job than cheap ones.

Till this day, the only true way to measure humidity is with the wet bulb technique. Two thermometers are calibrated to read identically. One has a damp piece of felt on the mercury bulb and air is lightly blown at both. Evaporation of the damp felt causes the wet thermometer to read lower than the other. The amount of evaporation that takes place depends on how humid the air is. The difference in temperature between the two is a direct reflection of air humidity. The values are looked-up on a chart or plugged into a mathematical equation and out comes the actual value.

In reality, barometric pressure is also needed because air is not an ideal gas. Barometric pressure only changes by a few inches (of water pressure) and that factor can safely be ignored unless you want really accurate readings.

FWIW: I did a lot of graduate study and experiments on high-speed wind tunnels (early 80's). A couple percent miscalculation of humidity can have disastrous results in those venues.

Anyhow, for instruments, nothing fancy is needed -unless you're storing a Stradivarius... Us mortals just need a meter that's in the ballpark.

Those electronic wand types that I showed earlier are probably pretty close to reality. I used that to test my cheap ones and threw-out all the really high and low fliers. I did a wet bulb experiment to verify the fancy electric one.

Ray

[cooper59]

Originally Posted by Ned Milburn

To the OP...

After you verify your RH, if you determine you should be humidifying, get yourself some Kyser soundhole humidifiers. They are the only ones that are effective for outside-the-case body humidification. They will NOT humidify the fingerboard, so if your humidity is indeed low, you may find you have fret ends poking out a bit. These can be rectified by a quick filing/polishing operation.

@ Ray... FWIW, I purchased 5 different "el cheapo" hygrometers from Amazon and tested them with Boveda's kit. They all came within 2 points of each other and are well within a functional margin of error.

The mechanical (analog) spiral spring style hygrometers are fine, too, since they can be easily set to the target humidity. Even if their calibration is off (not the setting at target RH, but the calibration of increments), these will provide the information needed to tell if you are near the target humidity.

Although instruments tend to be built near 40%, a comfortable keeping range for RH can be anywhere from 40 to 55%. I usually suggest 50%+-, since the guitar's wood WILL dry and shrink somewhat over the years, and a bit more humidity is better than a bit too little humidity. The guitar is built with expansion joints. Less than 40% and you get into crack territory.

well too much humidity is as bad if not worse than too little. also I went 40 some years without using humidifiers and have had a total of 0 cracks and I live in northern mi where heat is used 9 months of the year. needless to say I do use a humidifier now but keep it around 40. generally that's what guitars are built in so that's perfect