Guitar Care Guide

Written by Kenny Prochazka

On the way through any given year, you may not realize how much each season affects your guitar. As temperature and humidity fluctuate, wood tends to expand and contract, and that can lead to a number of issues, even in solid-bodied electric guitars.

The ideal temperature for wooden instruments lies between 65–75°F (18–24°C), with the ideal humidity between 45-55%. Outside of these ranges, shrinking and swelling wood can do a number on your tuning, your action, your frets, and even the angle of the neck to the body.

Let’s explore the ways that each season can affect your guitar, and what you can do to minimize any issues.

The two main challenges that most guitars face during summer months are excess humidity and heat.

Moisture in the air can seep into the porous wood of your guitar, causing it to swell. A solid slab body will usually be pretty warp-resistant, but the same cannot be said for the much thinner neck, and the even thinner fingerboard. As neck woods swell, they can exhibit a host of issues ranging from high action to a warped neck.

The effects of humidity can be even more severe with a glued-in neck, especially if the two joined parts are cut from different types of wood. Different rates of swelling can cause a shift that seriously affects a guitar’s playability.

Heat is rarely the friend of any musical instrument, and can cause a number of issues with everything from your finish to your tuning. Extreme heat can soften the glue in any joint of the guitar, making it especially hazardous for hollow instruments. It can also soften your guitar’s finish, and combined with direct sunlight can cause noticeable discoloration.

While the wood of your guitar is the most susceptible, high heat can also cause your metal strings to go flat, and in some cases can even melt or thin the lubricants inside your potentiometers.

To combat against the effects of heat and humidity during the summer, there are a few things to do, and a few things to avoid:

Things to do:

1.) Dehumidifiers are your axe’s ally when the air begins to get steamy. There are a number of products on the market ranging from single-guitar devices to multi-instrument walk-in humidors, so it will depend on what works best for you - but any effort at decreasing the humidity around your guitar(s) is better than doing nothing.

2.) Wipe down your guitar after playing. Summer heat brings more sweat, and that sweat is almost guaranteed to get on your instrument. This can lead to rusty strings, which is bad enough, but it can also lead to corrosion of metal bridge parts and even seep into your pickups.

3.) Clean your entire guitar regularly. Beyond sweat, any residue from bug spray, suntan lotion, or any other skincare product can end up on your guitar and can eat away at the finish.

Things to avoid:

1.) Do not leave your guitar in a hot car. On hot days, the temperature in a parked car can reach upward of 160 degrees Fahrenheit, which can loosen any glued parts from an acoustic bridge to a set neck pocket, and even the glue between the neck and the fingerboard.

2.) Keep your guitar out of direct sunlight as much as possible. These powerful rays can fade or crack your finish, can warp any plastic parts like pickguards, and can even cause your neck to warp by heating it unevenly.

3.) Try to avoid moving your guitar from a very cold place (AC on full blast) to a very warm place (outside under the hot sun), or back the other way. If you have to do so, be sure to allow some time in its case for it to acclimate to the new environment. Rapid temperature and humidity swings can cause spiderweb cracks in the finish, known as “finish checking”. They can also stress any glued wooden parts and can even cause condensation to form that can make its way into any unsealed parts.

The autumn months begin the descent toward winter. This season can be less extreme, but far more inconsistent, so it presents its own issues for your instrument.

As with the summer, you will want to avoid drastic temperature changes as much as possible, and always be cautious of the moisture that still fills the air. The inconsistency of the weather and the environment is key here, so it is not entirely surprising to have your guitar feel and respond differently from day to day.

When the weather starts to swing colder and dryer, you will want to adjust your guitar care accordingly.

Sitting opposite the summer, the main issue raised in the coldest months is pretty much the reverse of those found during the summer: colder, drier air. We try to keep our homes as livable as possible, but cranking up the heat can seriously dry out the air where your guitars live.

As much as humidity can cause wood to swell, its absence can shrink or crack wood in a number of problematic ways. Wood and metal do not respond the same to dryness or cold, so it is not uncommon to find frets sticking out of the edges of your fingerboard, or even to experience minor neck bowing which can lower your string action to the point of buzzing.

The porous nature of wood can make it easy to understand effects of temperature, but many players are unaware of how it can affect other components as well. Cold weather causes even metal to shrink, including bridges and tuning keys, potentiometers and switches, which can result in tuning sharp and/or affect the function of components.

So how should you care for your guitar during the winter? Much like summer, there are a few “shoulds” and a few “should nots”.

Things to do

1.) Use a case. It may sound simple, but giving your guitar a barrier against any extreme temperatures is the least that you can do to keep it in tip-top shape. And, when moving your guitar to a different environment, it not only protects from bumps and drops but also helps to maintain the immediate temperature and humidity that your instrument is used to.

2.) Invest in a humidifier and hygrometer. Depending on your location and needs, there are a number of ways to attack this, but monitoring and adjusting humidity can help your guitar avoid the worst that cold temps can dish out.

3.) Use a fingerboard conditioner. Especially with unfinished woods, you should apply a conditioner every time you change strings, or at least every couple of months. This not only helps to introduce regulated moisture into your fingerboard, but can even keep excess humidity out.

Things to avoid

1.) As with the summer, moving your guitar from one extreme temperature to another is a recipe for disaster. If you have to do so, you should ideally allow your instrument to rest in its case for 30-60 minutes so that it can acclimate to the new environment.

2.) Still don’t leave it in a car on a sunny day. Your vehicle’s interior will heat up inconsistently and can do a number on your finish, your action, and your guitar’s playability. With hollow instruments, it can even separate the glued seams of the body or neck pocket.

3.) Do not put your guitar near a heating vent, radiator or other source of heat. It may sound like a good idea, but heaters will dry the immediate air below optimum humidity, and can cause uneven expansion of wooden parts.

As the weather begins to warm, flowers bloom and birds return to chirping, we also see the reemergence of humidity and heat, and the impact that they can have.

Once again, inconsistency will be your guitar’s enemy. You will want to be aware of any temperature swings and always allow your instrument to acclimate in its case before using it.

When heat haze begins to glow over asphalt, and you start to think about turning on your AC, you will want to begin preparing (again) for the sweltering summer months.

Year Round Care

So what can you do for your guitar throughout the year, to keep it at its very best?

1.) Use a case when transporting your guitar. This has been mentioned above, but bears repeating. A guitar case will help to keep your instrument from experiencing rapid swings in temperature and humidity, which can not only make it play better but can also increase its lifespan.

2.) Maintain a steady environment. Outside of extreme highs and lows, most guitars will eventually stabilize when they become used to the surrounding temperature and humidity. When you make any changes to that, your guitar may take some time to adjust, so be patient.

3.) Regularly inspect and maintain your instrument. You cannot fix issues if you never know about them, so you will want to check for any problems whenever you get a chance. Also, throughout the year, as the weather takes its toll on your action, learning how to properly adjust your truss rod can save you a ton of frustration from an axe that is not in prime playing condition.