Shortly after reaching the Hawaiian islands in the late 1800s, Portuguese sailors discovered koa, a wood with high resonance qualities that was perfect for making four-stringed ukuleles. In addition,
its beautiful grain could be sanded to a glassy smoothness and finished to a lustrous sheen, making it a modern luthier's favorite, too. The most highly figured wood comes from Hawaii's mountains, growing to about 70' with trunk diameters from 5' to 8'.
Koa is an evergreen with yellow springtime flowers. The heartwood is golden brown with wavy streaks of red, orange, black, or yellow. An interlocking grain is responsible for much of koa's dramatic figure (often a fiddleback pattern), and contributes to the wood's high shock resistance and good bending characteristics. These qualities make koa a favorite for gunstocks. The Hawaiian name Koa-ka (valiant soldier) aptly describes this extremely decay-resistant wood. Screwing or nailing into koa yields excellent results, with very little splitting or splintering.
Beyond musical instruments, koa is a fine wood for carving and turning, making it popular for jewelry and art objects. Working with koa reminds many people of walnut. The wood is slightly open- grained, even textured, and has a moderate weight. It's one of the easiest woods to dry by kiln or air, and once it is dry, koa is quite stable and exhibits relatively little movement.
Wood grain images provided by HobbitHouseInc.com