Wood of the Month:
Hawaiian Koa is an Exotic Domestic Wood

By Jo-Ann Kaiser


FAMILY NAME
Acacia koa of the Family Leguminosae

COMMON NAMES
Koa

HEIGHT/WEIGHT
Average height is 80 to 85 feet. Average weight is 41 pounds per cubic foot with a specific gravity of 0.67.

PROPERTIES
Koa seasons well. Experts report the wood dries easily, usually without problems; however, any tendency to cup can be corrected by last stage kiln drying. Wood works easily with hand and machine tools, however experts recommend a reduced cutting angle of 20 degrees when planing or moulding material with a curly grain. Wood is easy to nail and takes screws well and finishes very well. Care needed for gluing. Wood has medium bending strength and stiffness, with high crushing strength and good resistance to shock loads. Small movement in service.

The Hawaiian Islands are home to many varieties of trees, but the large koa tree is the only acacia that grows naturally in Hawaii.

Koa grows widely in all of Hawaii's eight main islands. As a naturally occurring forest tree, it offers an important wildlife habitat. Koa is also grown as a plantation tree and is part of a land reclamation project designed to provide cover on areas that were damaged by grazing.

Logging with Care
Ben Clift, sales manager for Danzer Specialty Veneers Inc., of Edinburgh, IN, described the unique way that koa is logged by his company and others. "Koa is one of several woods that is logged by helicopter, a method of logging used to protect the environment," says Clift. "It preserves the logging site and surrounding area as much as possible. Access roads, for example, are not needed when the logs are removed in this way."

Koa is prized for its warm tones, which vary from a golden to reddish brown with a contrasting stripe. It can have an interlocked grain that will produce interesting figures, among them wavy, curly and fiddleback figures. The Fine Hardwoods Selectorama describes koa as being naturally lustrous with a "walnut-like texture but not as hard."

"Our customers like the material with more contrast as well as a figured or curly grain," says Clift. The wood is available in limited quantities in lumber and veneer.

Clift said koa is a popular wood with a long and colorful history in the state where it grows. Hawaiian songbirds nest in koa trees. Palaces from an age when Hawaii was ruled by kings feature woodwork entirely done in koa. On the mainland, koa is used primarily for high-end furniture, wall panels and musical instruments, according to Clift.

In Hawaii, koa is used to make a wide range of specialty items as mementos of the islands. Bowls, candle holders, clocks, coasters, flower stands and vases, frames, lamps, lazy Susans, letter openers, mirrors, oil lamps, pens, trivets, specialty boxes, cribbage boards, chess boards, chess pieces, Hawaiian game boards, whistles, jewelry, religious articles, photo albums, rockers, tables, and chests are among the specialty gift items made from the wood. You can even buy a backscratcher made of solid koa wood or chopsticks, gunstocks, hair ornaments, or woodenware.

Musical Fame
Probably the most well-known end use of koa is for musical instruments, specifically the world-famous Hawaiian ukulele. Legend has it that ukuleles were patterned after a small guitar that was brought to Hawaii by Portuguese settlers in the late 1800s.

Other uses for koa include architectural paneling, decorative veneers, interior joinery, shop and bank fittings, and bent work in boat building and coachwork.

The beauty of the wood as well as its innate properties explains koa's wide range of uses. Koa is very durable and is resistant to insect and fungal attack. It also has medium bending strength and stiffness, with high crushing strength and good resistance to shock loads.

                                                                                                                                                                                           

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