Koa is a wood that is indigenous to the Hawaiian Islands. It does not grow naturally anywhere else in the world. Also, it is Hawaii's most important tree species for economic purposes. It is a relatively fast growing tree, and thrives in full sunlight. Koa trees grow best in deep fertile soils that are moist and well drained, typically from sea level to 6000 foot elevations.
Koa's heartwood has beautiful colors ranging from a golden-brown to dark reddish or purple-brown. It has a medium to coarse texture with small, open pores. Also, the grain pattern is typically straight to wavy, but can have severely figured patterns that are interlocked and fiddlebacked throughout. These highly figured patterns are the very beautiful, and some of the most desired. Koa ranks average for stiffness, and bending strength, but above average for hardness, density, and shock resistance. Depending upon the specific climate zone it grows in, the density and weight of Koa wood can vary widely, but the average weight is about 42 lbs/cu. ft. Other interesting characteristic is that Koa has no appreciable taste or odor, but possesses very desirable tonal qualities. Also, it is ranked low in durability, due to its susceptibility to insects and decay.
Koa is usually easy to work with machine equipment and hand tools. It can become problematic if the grain patterns are highly figured. Tearing and chipping can occur when attempting to joint or plane the wood. Turnings and carvings can be accomplished easily, especially if the grain patterns are fairly straight or wavy. It is always a good practice to use sharp tools, and carbide tipped blades and cutters because Koa is easily burned. Koa holds fasteners very well, but pre-drilling is recommended. Koa sands well as long as sharp sandpaper is used. When the grit gets worn down and glossy, burning can result. Also Koa is not considered a particularly oily wood, and as a result most glues and stains work well. Koa accepts all types of finishes, and can be polished to a high luster.
Wood Species Index
Some of its uses are: cabinets, fine furniture, gun stocks, veneer, architectural paneling, and jewelry boxes. Types of carvings include sculptures, figurines, trinkets, and novelties. Koa is classified as a tonal wood, and is used in the construction of guitars, ukuleles, and other musical instruments. Also, because of its turning ability, bowls, pool cues, and fine pens are easily made. Due to its poor durability, outdoor projects are not recommended unless proper finish protection is applied.
All Exotic Woods: