If you live in Hawaii, for example, one wood type you might be familiar with is the Koa wood. This wood is gorgeous and of excellent quality. Yet is it suitable for use outdoors? Is it shock-resistant and decay-resistant? Besides, can you work with this wood with ease? So, before using this wood, it will help to seek to answer the abovementioned questions to ensure you would be using the ideal lumber for your project.
What is Koa Wood?
Koa has the scientific name of Acacia Koa, and this flowering tree is under the family Fabaceae. It also belongs to the Acacia genus and is native to Hawaii. Besides, Acacia Koa is the second most abundant type of tree in Aloha State. And Koa literally means bold, brave, or warrior.
Of course, you will find this tree in the big islands of Hawaii, but it thrives best on an elevation ranging from three thousand to six thousand feet above sea level. Reports say that Koa trees at higher elevations have more figured grains, while trees in the lower elevations wherein rains are abundant have straight grains.
Koa trees have a maximum height of 115 feet and a maximum trunk diameter of 4 feet. They also feverishly grow and have been farmed to conserve soil and lumber. Thus, most of the Koa wood you can buy in the market originate from plantations. Besides, this wood species is not tagged as endangered.
Properties and Characteristics of Koa Wood
If you intend to use Koa wood, it will be best to learn more about its characteristics and properties to determine if it is the most appropriate wood for your project. Below are the distinct attributes of Koa wood:
Colors and Appearance
If you would ask me if Koa wood is beautiful, I would readily nod and say, “Yes, it is!” It is, without a doubt, one of the most elegant and beautiful woods out there. It is unique because of its excellent colors, textures, and figures.
However, such features depend on how old the tree is when cut, its habitat or elevation, and the soil wherein it grows. Its range of colors is from deep chocolate brown to light golden blonde.
Its color, of course, may vary. You will also see contrasting color bands in its growth rings, and you will notice boards likewise with streaks of ribbon-like color. Moreover, you will notice curly or wavy grains on its boards.
The remarkable thing about Koa wood is its diverse grain patterns. Although Koa wood with straight-grain patterns is the most common, you will also see wood with figured, wavy, and curly-grain patterns. The most normal-looking grain patterns, of course, are straight grain patterns. Besides, Koa wood with straight grains is the most abundant and affordable.
The tight and curled grains often produce holographic looks for the wood, which is somewhat three-dimensional. This three-dimensional appearance gets referred to as “chatoyancy,” which is Koa’s most unique feature.
However, the wavy and curly grain patterns are less common and more often seen among old-growth trees. But these are the most desirable patterns for this wood, and Koa wood with these patterns may command a higher price. Figured patterns, on the other hand, get created when the tree is stressed. You will often see these grain patterns in twisted or forked branches.
Koa wood is not known for its high resistance to decay and rot. It also gets rated as perishable to non-durable. Besides, it is vulnerable to attacks by termites. Thus, it is not advisable for outdoor usage.
The Koa wood is quite stable. It can expand or shrink by one percent across its grain if there is around a five percent change in its moisture content. Moreover, you will not notice any significant difference in its stability, whether it is flatsawn or quartersawn.
Strength of Koa
Koa is quite strong compared to other wood types. It has a Janka rating of 1,170 lbf. Its ultimate strength or MOR is 7,060 lbf/in², while its bendability is around 1,503,000 lbf/in². Compared to Maple and other wood, Koa exhibits remarkable elastic modulus.
Advantages of Koa Wood
One way to ensure that a particular wood is appropriate for your woodworking project is by checking out the advantages of its use. Thus, it will help to know the following succinct benefits of the use of Koa wood if you want to use it:
As mentioned above, Koa wood has a remarkable elegant, and attractive look. The combination of its color and texture is superb. Thus, if you want unique wood with excellent grain patterns and texture, you should go for Koa wood.
Easy to Work With
Another remarkable characteristic of Koa wood is its high level of workability. You can efficiently work this wood out using your hand or machine tools. Besides, it receives stains and finishes nicely, resulting in an excellent finish.
Easy to Maintain
Koa wood requires minimal maintenance and care. It is sufficiently hard to resist scratches and dents. Caring for this wood, however, varies based on the wood piece you have. Besides, it necessitates periodic dusting and oiling. You can also refinish it using the recommended wood polish and sealant.
Disadvantages of the Use of Koa Wood
As you learn about the pros of using Koa wood, you can now decide if Koa wood is perfect for your future project. Yet, it will also help if you are cognizant of the following disadvantages concomitant with its use:
Not Rot or Decay-resistant
Although Koa wood is hard and strong, it is not decay-resistant. Thus, you can’t use it outdoors and place it in locations that have contact with moisture and soil. Besides, it is vulnerable to termite attacks.
It is Expensive
Koa wood is unique because of its excellent appearance. This uniqueness and its other remarkable properties make this wood a bit costly to use.
Applications and Uses of Koa Wood
The beautiful Koa wood has many fine applications and uses. First, you can work on it to produce remarkable furniture. You can also use it for woodturning to create exceptional small wood items. Plus, you can use it for sculpting. Besides, it has been used for musical instruments like ukuleles, steel guitars, and acoustic guitars.
Furthermore, some manufacturers of electric guitars use this wood as components of their electric guitar products. For example, Fender used Koa wood in limited models of their Stratocaster and Telecaster in 2006.
Another characteristic of Koa wood is its high level of shock resistance. Thus, it is suited for making gunstocks. It can also perform well as boat trim. Moreover, you can use it for veneers and architectural paneling. Besides, in the past, ancient Hawaiians used to create canoes out of this wood and even surfboards.
How to Work with Koa Wood?
As mentioned above, it is not hard to work with Koa wood. It is also easy to sand and finish. Nevertheless, you will have a hard time working with heavily figured Koa wood with interlocking grains. You might tear or chip its grain when you use your machine or plane. Besides, you might sometimes have issues when gluing Koa wood. Nevertheless, Koa wood stains and finishes nicely.
Koa dries fast and easy. It doesn’t cut or split. Moreover, it is like the hard Maple when it dries. Besides, Koa’s shrinkage percentage when drying is around six percent.
Machining and Gluing
Koa wood is a bit brittle, especially when it gets over-dried or if it has variable density. Besides, you will find some Koa wood with curly or swirly grains. Thus, sometimes, you will encounter Koa woods that are difficult to machine and work with. In such a case, you will need sharper tools.
Besides, the wood will exhibit burnishing if you don’t use sharper tools. Nevertheless, if you use sharp tools, you can produce excellent cuts and finish with this wood.
Koa wood is quite stable. As mentioned above, it alters its size by one percent when its moisture content changes by five percent. So, its stability is not a big issue.
What Makes Koa Wood Unique and Special?
Upon hearing the name of this wood, you might intuitively assume that this wood is something special. Well, such an assumption is correct because Koa wood is extraordinary. First, it only grows in the State of Hawaii. Besides, it once dominated the Hawaiian land. However, many of these areas have already been converted to grazing and agricultural lands.
At present, the availability of Koa wood is quite limited. Very few private lands have old-growth Koa trees whose woods get highly desired. Besides, harvesting Koa wood is already illegal if the trees grow on public land. It usually takes fifty years for Koa trees to mature and develop the curly grain patterns sought after by buyers.
The increasing demand for Koa wood for guitar manufacturing also contributes to the scarcity of this wood. Koa wood, of course, has excellent tonal properties that musical manufacturers seek.
Besides, Koa has an excellent aesthetic appeal which makes it very desirable. Nevertheless, this incredible appeal of Koa wood drives the availability of this wood further down while pushing its price higher.
Koa is undoubtedly a highly sought-after wood because of its sterling qualities and characteristics. As such, it is rare. You are fortunate if you have furniture made of Koa wood. Because of the limited supply of Koa wood, many people turn to Acacia wood as an alternative to Koa wood. These two wood types, of course, feature almost the same qualities. Nevertheless, Acacia wood is more available and is less expensive than Koa wood.
If you have furniture made of Koa wood, you should take care of it, for it is rare. Take extra effort to maintain it, for Koa furniture will always be a conversation piece because of its elegance and beauty. Lastly, you should know the best practices for keeping it to ensure its longevity.
Liam is a 37-year-old woodworker and interior designer who loves to make every furniture project an art piece. He is very experienced in furniture design and woodworking project planning.