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Oklahoma, Humidity, and Guitars

Oklahoma Weather

I once had someone explain to me that humidity wasn’t an issue with guitars.  They figured that since trees needed water to grow and lived through dry summers, etc. etc – you just didn’t have to worry about humidity.  Wrong! But worrying isn’t the solution either.

Heat and weather cycles have an effect on your acoustic guitar and other stringed instruments.  The wood can swell or shrink, and the glue that holds those beautiful woods together can be directly and indirectly impacted.  The effect is, according to some, more severe on newer instruments.  The effect can also be seen on solid body instruments but not as readily.

Hopefully you’re not using your guitar for an oar and dipping it in the river, so let’s talk primarily about humidity.  According to everybody’s favorite (?) encyclopedia, Wikipedia, “Relative humidity is a term used to describe the amount of water vapor that exists in a gaseous mixture of air and water, expressed as a percentage of the maximum amount of water vapor that could be present if the vapor were at its saturation conditions.”  One of the many nice things about Oklahoma is that humidity ranges, through out the year, between 35% and 65%.  That’s a tolerable range, though the 35 is pushing close to the “cracking point.”  (Acoustic instrument builders will generally try to keep their work area in the 45% - 50% range.)

Three Hazards

Our Oklahoma temperature ranges from below zero to close to 100 during the course of a year.  Trying to keep the house warm with forced air drives the humidity down and that’s usually when problems arise.  So when you turn on the heat, start paying extra attention to the humidity.

If the humidity climbs above normal, as it appears to have done with the Oklahoma rains of 2007, you’ll find the dangers not as severe as the dryness, but there are still concerns.  As the wood swells with higher humidity you may find a duller, more woody tone.  You may also find that prolonged swelling will force apart glue joints, though this is probably less common than cracks from dryness.

When the temperature hits 90 or so, be very careful of where you leave the guitar.  In a parked car where the temperatures climbs rapidly you might be getting your well playing guitar ready for a neck reset.  Repair folks use heat to loosen glue joints – but under very controlled conditions.  Don’t do it in your car.

Symptoms

There are a wide variety of symptoms related to humidity, many of which occur after the damage has happened.  One of the first signs might be a change in the action.  As a guitar dries out and the top sinks (even slightly), you may find that you have fret buzzes where there had been none.  If your frets are good, and the guitar is buzzing during the winter when your heating system is on – it could be low humidity and a sinking top!

Visible changes in the bridge or a sense that the frets are poking out are other signs of the instrument drying out, but not necessarily early signs.  Cracking on the top is one of the most visible signs and can happen very quickly.  A good friend was showing a guitar he had built in Oklahoma at an outdoor festival in Colorado – it took only two days to crack!  (Don’t panic – see below.)

It is also possible to see back or side cracks due to low humidity, though these are less frequent.  The back may move as the top does or the neck may bow.  None of these are killers – they will not destroy your instrument, but they can be avoided with proper care.  Don’t be afraid to use your guitar, just use it with a little tenderness!

One last thought on symptoms.  You obviously will not see a top collapse on a solid body instrument.  The symptoms are more subtle and it will take longer for them to appear.  Possible bowing of the neck or fret ends protruding are more likely to give notice that a little more care is needed.

Preventive maintenance

My kids were surprised many years ago to find that I still had toys from when I was a youngster – and the toys were still in working order.  I’m not a fanatic, and you don’t have to be either to protect your instrument from the evils of humidity.  For us in Oklahoma, the biggest concern is the winter months and dry heat.  At the extreme, you do not want the humidity in your home below 35%.  Your ideal range, and relatively easy to achieve, is 45% - 55%.

Use a digital hygrometer to check humidity.  You can find one for about $20 and it is more reliable than the $10 model you find at the dollar stores.  If you have a humidifier built into your HVAC system, make sure it is working and use it to maintain the proper range.  Controlling humidity in the house is not that difficult, but is a large scale issue.  If you do not have the ability to impact your home environment, control it within the instrument case.  There are a wide variety of choices of in case humidifiers, I tend to think that sound hole humidifiers are the best choice especially if you follow the other primary rule – keep it in your case when not using it.  Whatever type of humidifier you choose be careful to follow the instructions.  If misused you may end up watering your instrument!

Some folks will tell you that it is more important to manage humidity with a new guitar than an older one, new being the first 1- 2 years.  There seems to be some logic in this, but if you get in the habit of taking care of your instrument why would you change that pattern as it ages (and because you are aging also is not a good excuse).

Keep your instrument in the case when you are not using it.  I’ve heard guitar teachers tell their students to leave the instrument out on a stand so that they see it and remember to practice.  If you need the reminder, try a string around the finger.  Avoid the risk of the dog or cat or kid or just your own clumsiness before that first cup of coffee.  An accidental fall off the stand can cause serious damage.

If you must keep it out in the open and you decide to hang it, make sure you use an interior wall that will have less environmental changes than one say on the north side of the house.  Also, avoid the vents.  A friend had a guitar on consignment at a shop in town and the owner hung it high and in line with the vent – little surprise that the instrument cracked during the winter months with the heating turned on.  The same applies to a guitar stand.  Get a good solid one, and make sure that the material touching the instrument will not damage the finish.

Special Circumstances

So let’s say you have to go to Winfield!  (No where near as big an environmental issue as going to the Rockies or Arizona.)  When traveling keep the instrument in the case when you are not playing it.  Treat it with care – wipe it off when you’re done playing, use your humidifier (or if you go to a really wet climate try some of the silica packs).

You wouldn’t leave your kid in a parked car with the windows up in hundred degree weather – don’t leave your guitar or mando in a similar situation.  If you have to leave it unattended while you’re traveling, make use of that sleeping bag you use at Winfield and wrap it up.

When Cracks Happen

If you do find a crack, fix it!  Crack, scratches, etc will happen over time.  Some add character like the wrinkles in a well worn face.  Open cracks can hurt.  If the crack is new, it will be easier to fix then than later.  You can try it yourself, but the more I see of poorly done guitar repair the more I understand the need to do it right the first time.  It is much more difficult to re-do a poor repair job than to do it right the first time – and guitar and mandolin repair people are not that expensive in comparison to what you have invested in your instrument.

As cracks age they get dirty, and they also work their way into the memory of the wood (you’ve heard about “smile wrinkles”).  If you have a crack fixed that’s been around for a while, don’t expect that it will be closed by tightly clamping the instrument – it may take a spline which may sound scary but it will not hurt the instrument.  A friend of mine owns a Gibson that is reported to be an absolute one of a kind.  It has a significant crack or two, and he’s been advised by some experts in the vintage guitar world to not have the cracks fixed in order to preserve the vintage value.  As the value of some instruments becomes an issue you run into special circumstances like this.  If you think the instrument you have is a vintage investment piece, talk about it to someone who has a sense of that market before you have any repairs or alterations done.

Back to Start

Take care of your instrument and it will last a life time, perhaps more.  Be sensitive to the environment that your instrument exists in, and monitor humidity.  As you use a humidifier, be sure to Read and Follow Instructions.  And have lots of fun playing.

Ed Cunliff, MandoAiki
You are welcome to use this article on your website, blog, or in your newsletter as long as you include this complete credit line:  Copyright 2008 Ed Cunliff.
 

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