Humidity and Your Guitar

Courtesy of Fred’s Music Shop

Frequently, we have a lot of damage occurring to “better” acoustic guitars over the winter. Many of our customers have instruments that have developed cracks, etc. from lack of proper humidity over the winter. Having a heating system that is “hot water”, in other words… radiators in the rooms… is NOT a system that supplies ANY form of humidity to the air! Many of our customers are baffled by the fact that even though they have “hot water” heating systems… their guitar still cracked!! The reason for this is that the “water” is INSIDE the radiator and does not enter the air… the air is dried by the heat just as much… and maybe more than with forced-air systems. If you have a “better ” acoustic guitar… one with solid woods… it is IMPERATIVE that you keep the air at a proper humidity… in most cases… the MORE THE BETTER ! In the early 1970’s, when our store was on North Ninth Street in Reading, I once had a 1939 Martin D-18 crack overnite ! I was playing it… put it on a stand and went home… and the next morning when I came in the top was cracked and I was baffled !?! I had “Hot Water” heating… why would my guitar crack?? Well, when I actually took a humidity reading… I had basically NO HUMIDITY! Since then, I either keep the humidifier going or keep my good guitars in my basement where the heating system has no effect. In our store, we recently installed new high-output systems on the main heating systems and if you visit our acoustic guitar displays, you will notice that we STILL use a room type humidifier to augment the system and we constantly monitor the humidity with and electronic meter. We like our guitars… so we humidify over the winter !! If you want to check your guitars… here’s some quick ways that I use to tell if my guitars are drying out.

#1 – is the action getting lower? The guitar is getting really easy to play? Faster action than you remember? If so… the top is “shrinking” and lowering itself and getting ready to split… watch it!!

#2 – is the sound getting buzzy – more fret buzz than you remember. Same as above.

#3 – when you run your fingers down the sides of the fingerboard… are the fret ends sticking out slightly? (or more?)… think of the wood as a sponge… the fingerboard is drying out and shrinking… the metal frets don’t shrink… so they stick out!!!

If the answer is yes to any of these… it’s probably yes to all of them and your guitar is drying out… watch it!!

Here’s a letter we recently received from Taylor Guitars – this memo was sent to all dealers warning them of low humidity conditions.

Sight-reading Humidity – a letter from Taylor Guitars

Many of our dealers have come to understand humidity, and, as a result, have increased their sales and decreased the damage to their solid-wood guitar stock. In fact, many dealers have totally eliminated any damage to their guitars in winter months. All of us here at Taylor Guitars thank you very much for your efforts! A few dealers, however, are still encountering dryness problems and sending guitars back for repair. Reason: Your humidifiers might not have the output capacity to keep up with the amount of forced-air heat required to keep your building warm during extreme cold spells. Although we recommend commercial humidification units that hook up to your main water supply, any humidification system (portable or permanent) must have the capacity to supply enough water in the driest times of the year. For most stores this means the coldest days of winter.

Frequently, we’ll have two dealers in one town who manage their humidity differently. One will experience horrendous problems with their guitars, while the other has no problems at all. Here in El Cajon, the humidity outside often is lower than 15 percent, yet we are unaffected because our humidification capacity is sufficient and the equipment is monitored and well-maintained. No matter how you humidify your store, the bottom line is getting enough moisture into the air. We have found ourselves arguing that point with people who have returned guitars with sharp frets, sunken tops, etc., and who feel that since they have some sort of humidification, they’ve done all they can do; they expect us to step in and make up the difference. We remind them that it takes low humidity to dry out a guitar.

There are many variables in humidification, and they can wreck havoc on your Inventory, often without you noticing. Here are some helpful hints:

a) is the hygrometer being used properly? Needle readout types tend to go out of calibration every 6 to 12 months. A sling psychrometer is then used to re-calibrate it. b) Guitars can become dry due to air moving across them, so placement of heating ducts is important. Close them or turn them if they are close to your acoustic guitars. c) Your humidified acoustic room can be adversely effected by inside heating ducts and open doors. d) Heat rises, so acoustic guitars should not be stored high on a wall, or hung from a ceiling. e) Areas close to exterior doors can be drier than those near your humidifiers.

These tips are especially pertinent when your humidity capacity is too low, or almost too low. With sufficient output capacity, managing all these variables becomes almost unnecessary. Reading the guitars: One reliable indication that a fairly new Taylor guitar is drying out is the pitch of the neck angle to the body. Method. To judge the neck angle on a Taylor, first set the guitar on a counter or bench. Second, lift the headstock and look down the plane of the neck. (Make sure the neck is adjusted straight from the Ist to 14th fret with the truss rod.) Using the plane of the frets as your straight line, aim the neck at the thickness of the black ebony bridge on the body, just like aiming the barrel of a gun at a target. (Ignore the saddle.) Are the guitars dry? If the plane of the frets is pointed over the thickness of the bridge, the guitar’s top has sunk from drying out and the strings will be lower. Our neck angles are set to line up no higher than the thickness of the bridge. I might add that it is impossible for the string height to lower for any other reason than low humidity. Sharp fret ends are another indication. What to do? We realize that all store owners will not take care of their humidity to extent that others will, due to various reasons. We also realize that extreme humidity situations are not the norm for everyone. (For example, the winter of 94/95 was very mild and we therefore had few problems, while 95/96 was extremely cold.) Using the above neck angle method is the one true way to know if your humidity is sufficiently high. If after judging this, you find your guitars are dry, I can easily instruct I you over the phone how to re-humidify these instruments back to good playing condition, without having to send them back.

Copyright 1996 – Fred A. Bernardo
Fred’s Music Shop – 212 W. Lancaster Ave., Shillington, Pa. 19607


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