Take care of your guitar

Better safe than sorry..

The humidity, or lack of humidity can be your guitars worst enemy.
Knowing how it affect your guitar and what signs to look for can save you both for costly repairs and a devalued instrument.
As they can`t control the enviroment you keep your instruments in, no manufacturer will give you a refund for a cracked top or other humidity damages.
We highly recomend that you take the time to read this thorough article written by Terje Menyjærvi!

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Observe The Humidity

Written by Terje Mentyjærvi, Luthier

There is a constant exchange of moisture between the air and the wood of your guitar.
The more parts that are made of solid wood, the more vulnerable the guitar is for damage! The humidity describes the amount of water vapor the air carries in terms of what it is capable of at a certain temperature. It is ideal with 45% – 55% relative humidity. The humidity is measured with a hygrometer.

Warm air can carry more water than cold air. If cold air is heated it increases the air-bearing capacity, but not the amount of water. The relative humidity is therefore much lower than when the air was cold. New guitars are often built under different climatic conditions and in controlled environments. It is therefore particularly important to be aware of the humidity in the first two to three years so that the guitar slowly adapt to the climate. This applies no matter which brand it is on the guitar. Damage caused by the guitar not being protected against changes in humidity are not covered by any warranty.

Good guitars are built by good wood and good wood is sensitive to changes in humidity. A guitar top made from spruce on a Dreadnought that is well dried and adjusted to 47% humidity can shrink by 2-3 mm when it is adapted to 30% moisture. The same piece of wood can be approx. 1.5 mm wider than it was when it is adapted to 60% moisture.

A winter can inflict serious damage to your guitar! As an example, here in Norway the humidity varies a lot with the seasons. Late in the summer it can reach up to 90% and In the winter it can creep down to 20% over a longer period. This means that the guitar owners have to pay close attention to keep the guitars from drying out or swelling. Guitars with a top, braces and bottom of solid wood are particularly vulnerable to changes in humidity.
In Norway it is especially important to follow the humidity in the winter since we have a long dry period, while the wet period is relatively short.

Typical drought damage in the low humidity:

  • Fret ends protruding from the edge of the fretboard.
  • Neck leaning backwards.
  • “Bump” in the fingerboard by the neck joint.
  • Lower string action because the top flatens out.
  • Fret buzz.
  • Need for truss-rod adjustment.
  • Cracks in the guitar top, bottom and braces.
  • Loose braces.
  • Flatter back.
  • Drought Damage around the neck joint and binding.
  • Loose frets.
  • Changed sound.

Typical damage caused by high humidity:

  • Loose glue joints and braces.
  • Guitar top and back with dents in the joints.
  • Fingerboard that expands can cause irregularities and possible release.
  • Need for truss-rod adjustment.
  • More stringent height because the top rises.
  • Changed neck angle.
  • Changed sound.

What can you do to take care of your guitars? Keep the guitar in a good transport case. Guitar case will partially insulate the guitar from its surroundings and slow cooling and warming. Let the guitar acclimate in the case for a while before the case is opened after it is exposed to large temperature changes. Add a hygrometer in the guitar case, and observe the changes in humidity. Read the moisture in the case only when the guitar has been in the closed case long enough for the moisture in the guitar and the case has been leveled out. Digital hygrometers are now cheap and readily available.

It is also good to keep a hygrometer in the room the guitar is stored in. Use a humidifier designed specifically for instruments in the guitar case when necessary. If the guitars are not stored in the case, the humidity in the room is monitored and increased when necessary by a humidifier. In large rooms, one must use humidifiers connected to the water system in the house. Humidifiers shall be used only when necessary. A guitar that is exposed to too much moisture can also be damaged. Remember that all changes in the moisture in the wood must take place over time.

Make sure the guitar is not affected directly by the heat sources such as heaters, heating cables, lamps, direct sunlight, heat pumps, hot cars, ventilation systems and the like. Remove from doors, windows and central heating that can dry out the instruments.