Fig. 4. If you don’t clean and condition your fretboard, it may crack.
Cracks are another terrifying byproduct of not conditioning your fretboard (Fig. 4). When sweat evaporates, it can dry out the fretboard and cause it to crack.
Fig. 5. If they’re not cleaned regularly, pickups, potentiometers, and switches can become corroded by the salts and acids in sweat.
A guitar’s electronics can also suffer from dead skin cells and sweat. When acids and salts build up on a pickup, they can corrode the coils and magnets and cause the pickup to fail. These corrosive materials have the same effect on potentiometers and switches (Fig. 5).
Many string and accessory manufacturers offer conditioners for your guitar. But be aware that most of these products, including lemon oil, contain harmful chemicals and solvents that will damage your guitar’s wood and finish. Avoid anything that contains d-Limonene, alcohol, or silicone.
Derived from oil extracted from citrus rind, d-Limonene contains natural acids. These acids can act as a solvent and break down finishes and cause the wood around the frets to deteriorate. Alcohol dries out the fretboard, bridge, and other unfinished wood, and can cause cloudiness in certain types of finish. Silicone prevents the wood from breathing and can cause the finish on your guitar to become hazy. It’s also very difficult to remove.
Fig. 6. When wood isn’t sufficiently humidified, it can dry out and crack. This guitar back has seen better days.
Controlling humidity is another important aspect of guitar care. When a guitar gets too dry, the wood cracks (Fig. 6). Conditioning wood certainly helps prevent it from cracking, but it’s also a good idea to use a humidifier. New guitars tend to be more prone to humidity cracks than older instruments. Here’s why: Most older or vintage guitars were made from air-dried wood. This wood was dried out over several decades, and during this process any pieces that cracked were culled out. The older harvested wood gets, the more stable it becomes, but it’s a lengthy, painstaking way to dry wood. Modern guitars are primarily made from kiln-dried wood. Kiln drying is designed to speed up the aging process, but only time can truly age a piece of wood. Guitars made from kiln-dried wood are more susceptible to changes temperature and humidity. Maintaining a guitar-friendly humidity level helps prevent wood from cracking, and we’ll discuss how to do this in a moment.