Since the beginning of time, wood has always been an essential material in guitar building. From classic to modern, acoustic to electric, wood is always a major part of making a guitar.
Different wood types used in building a guitar also result in different tones.
Using an alder wood for the guitar’s body will give room for more lows and will have a wider scope of tones, which leads to the perception of a little less mids than the basswood. Basswood, on the other hand, stimulates a weaker low end due to its softness. It leaves the mids pronounced as it does not resonate deep, breathy sub-lows.
Mahogany is mainly the most used wood as an acoustic guitar body due to its durability, attractiveness, resonance, and is easy to work with. It gives a twangier tone but not as brilliant, it is not as big sounding either but contains a distinct character. Koa produces a very balanced-sounding guitar as it has the warmth of rosewood and much of the brightness of Mahogany.
For woods used in making the fretboards, rosewood is the most common. Its sound is very warm, however, the high-end frequencies are dampened and are richer than Maple because the stray overtones are absorbed into its oily pores. Maple is also a popular wood for necks and fretboards because of its bright tones, grain patterns, and moderate weight. As a fretboard, it produces tremendous amounts of higher overtones.
Ebony, on the other hand, offers a bright attack, great sustain, and excellent durability compared to rosewood. It has a crisp attack with the density of Maple but with more little grains, oilier pores, and a stronger fundamental tone than a Maple. For Wenge, it makes a great bass neck with strong midrange tones and warm lows. It is usually used as a neck-shaft but can also be used as a coarse fretboard.
All these types of woods undergo a process to prepare them for building a guitar, and one of the processes is called drying.
Drying, also known as seasoning or aging, is a process used to reduce wood’s natural moisture content after it is cut. It gives any wood enough stability to resist shrinking, expanding, warping, and cracking. The quality of drying is an important factor in determining the tone quality and life of the guitar.
There are three most used methods on how to dry wood for guitar building; air drying, kiln drying, and very quick kiln drying.
The air drying method gives optimal natural conditions to take its course while eliminating natural elements that can ruin or otherwise change the wood in ways we do not wish. Wood will naturally lose its moisture to the environment, and giving a dry space and good airflow will do most of the work.
Kiln drying is a standard procedure in wood production mills. It is used to efficiently reduce green timber moisture levels to “workable” levels–moisture content levels that will not result in the variety of problems created by excessive moisture levels in wood.
The very quick kiln-drying has the same procedure as the kiln drying but has a shorter drying duration. This is used for low-quality woods and essentially used for very cheap guitars.
How Dry Should Guitar Wood Be?
So, how dry should a guitar really be? Many luthiers agree that the wood should reach the moisture content of its environment. The figure should be between six to nine percent. The main advantage of any wood with this moisture content is that it will not easily deform or change shape when the instrument is built.
For any wood to dry naturally, it needs to have certain conditions, and even then, it could take many years. For timber, it is estimated that it will dry for about 1″ or 2.5 cm per year. Therefore, if you have a 3-inch slab of wood, it would need an estimate of three years to dry.
Guitar factories maintain a relative humidity of 30 to 50 percent at a temperature of around 20 degrees Celsius, which is comparable to the six to 9 percent moisture content.
All luthiers agree with the notion that the longer wood can be kept in a stable environment before it is worked, the more stable the wood will be overall. It can deal much better with moisture changes without a detrimental effect on a guitar. This is one of the main reasons they buy wood long before using it.
How do you prepare the wood for making a guitar?
To use the air drying method for drying the wood needed for building the guitar, certain drying conditions must be thoroughly followed to achieve the best results.
The first is to stack the wood using the stack and sticker method and make sure to have a flat and steady base that allows airflow. Always put the supporting sticks close to the end and in 18-24” spaces. You need to cut and align all the boards, matching in length and having a ‘clean’ end with no checks or cracks.
Wax and use sealers as the ends tend to have to dry and shrink faster and, therefore, may crack. Putting the stickers close to the end also helps.
If you are air drying outside, make sure to cover it and protect it from direct sunlight. It is essential to have a fan or fans to maintain constant circulation. If you are doing it indoors, you must use a home dehumidifier and use a moisture meter to monitor the drying process.
For doing the kiln drying, it is important to remember that most kilns will have three main components: the Dehumidifier, fan, and heater.
The combination of heat, dryness and good air circulation from kiln drying can significantly shorten drying time and reach final moisture content as low as 6-8% moisture.
The usual commercial kiln temperature can run at 38-48 Celsius (100F -120F) and up to 65C (150f) for sterilizing. This means that a 2-inch stock can take a week or two for relatively softer wood like Poplar and up to 4 weeks for oak and other harder woods.
There are many benefits of using well-dried wood in building a guitar. A well-dried wood is less susceptible to deformation if exposed to different external and environmental conditions. A well-dried wood also loses some of its flexibility and makes it a more rigid material which is beneficial, especially for guitar necks.
A well-dried wood will also have more acoustic properties than undried wood. It will also have a reduced weight which is an advantage. Drying the wood will also eliminate the existing molds and prevent more from appearing.
Overall, it is essential to have well-dried wood to build your guitar. If you are also hoping to be a luthier someday, knowing the methods on how to dry wood for guitar building is really a must.