The Care and Feeding of Your Guitar
Your instrument has been built under strict climactic conditions. All woods are carefully seasoned and assembled at 40-45% humidity relative to room temperature. Your guitar is made to withstand moderate changes in humidity and temperature. However, excessive and prolonged changes in humidity or temperature may lead to damage. How you care for and protect your instrument will greatly effect it's appearance, tone and longevity.
Summer
When the relative humidity increases beyond 55-60%, the guitar will begin to expand. Some symptoms of this are:
A rise in action (height of the strings) is one of the major problems observed in guitars exposed to excess humidity. The change in action is caused by a number of forces which include top and back swelling and the expansion of the fingerboard. These changes will push the neck forward and lead to higher string height. As the instrument distorts, there will also be a loss of sound quality. All problems associated with exposure to short term high humidly should correct themselves when the instrument returns to the normal range of humidity: 40-45% relative to room temperature.
Most problems related to excess humidity can be avoided with some simple precautions:
Winter
The winter months are associated with low relative humidity. Exposure to rates lower than 40% will result in changes to your instrument which are more serious than problems associated with excessive humidity. As moisture in the air decreases below the normal range, your guitar will begin to shrink. Some symptoms of dryness are:
A common winter complaint is string buzz caused by very low action. This is the result of a combination of forces. A shrinking top and back plus a shrinking fingerboard will pull the neck backwards and that will lead to a low string height. The worst problem associated with excessive and prolonged dryness is the cracks in the top which can happen when humidity drips below 30%. The cracks may appear along the center seam and on either side of the bridge. As the top shrinks, it becomes possible for the bridge to separate from the top with a shearing action. A little common sense will help to avoid most winter problems:
When any of the symptoms outlined above are noticed, it should be seen as a warning sign that humidity is not optimal and precautions should be taken. A rule of thumb to remember is: Never leave your guitar anywhere that you would not be comfortable waiting yourself.
Maintenance
It is not necessary to apply any oil or wax product on your fingerboard if you play the instrument regularly. The natural oils from your fingers are sufficient to lubricate the fingerboard to prevent cracking. When changing strings, it is wise to go over the fingerboard with 000 steel wool (but be careful not to scratch the finish on the top). This will remove all the built-up dirt and grime. The steel wool will also polish your frets and the fingerboard making them more slippery and improving the playability of your instrument. Occasionally, clean your instrument with a slightly damp cotton cloth to remove dirt and improve the appearance of your guitar.
And in closing...
Your guitar has been constructed from various high quality seasoned woods and assembled under strict tolerances. It is a delicate instrument which can be affected by a variety of stresses. Which careful observation, common sense and care, your instrument will provide you and your listeners with a lifetime of enjoyment.