Koa 1
August 14, 2011 | 4:32 pm CDT

Wood of the Month:
Strum a Ukelele, and You Are Playing
Koa's Tune

By Jo-Ann Kaiser

Acacia koa of the Family Leguminosae


Average height is 70 to 80 feet.
Average weight is 41 pounds per cubic foot with a specific gravity of 0.67.

Works well with both hand and machine tools. Wood takes nails and screws well but can pose problems with gluing. Material has moderate blunting effect. Experts recommend a reduced cutting angle of 20 degrees especially if grain is considered curly. Wood has medium bending strength and stiffness, high crushing strength and good resistance to shock loads

Koa is considered a "domestic," but very exotic wood that grows exclusively in the Hawaiian Islands. With its high resonance qualities, it an excellent choice for wooden musical instruments, including the world-famous Hawaiian ukuleles.

Koa is also a striking looking wood, with a heartwood that is reddish to dark brown and regular black lines caused from the zones which mark the growth rings. Koa yields several attractive figures such as the koa crotch, with a rainbow of shades from red to brown, and the koa fiddleback figure.

Koa wood is not only attractive, it is naturally lustrous and takes a beautiful finish. Koa has an interlocked grain that can be wavy or curly and this also adds to the tendency to interesting figures. The fiddleback figure is especially popular for decorative veneers. Koa is popular for fine furniture and architectural work such as paneling. Koa is also used for gunstocks, interior joinery and in boat building. The tall koa trees were once hollowed out and shaped into canoes by Hawaiian Islanders.

Moratorium on logging
According to Christopher Jensen, president of Santa Monica, Calif.-based Koalition, "There was a moratorium put on commercial cutting of koa on state land in Hawaii about a year ago. Our firm cuts a percentage of dead and dying koa on private lands. We use the koa to make fine furniture, veneer and picture frames."

Jenson's company uses helicopters in logging, which can be a very expensive method. "We work with the forest owner, fly in, and set up a base camp for three to four days. The trees are felled and hoisted out by Baby Huey helicopters," said Jensen.

He added that koa is cut sparingly on private forestland in Maui, with the intent of only removing dead and dying trees, thereby opening up the forest to new growth. His company has been logging koa this way for four years.

Koa prices have risen dramatically, said Jenson, due to the moratorium on cutting on public lands. "What used to cost $2 a board foot to $6 a board foot for the best figured koa, now ranges from $22 to $30 a board foot," said Jenson.

Carl Booth, owner of Carl Booth and Co., of New Albany, Ind., is very familiar with koa in the veneer form. His company makes custom plywood and high-end architectural plywood. "Koa is one of the high-end exotics coming from the Hawaiian Islands," said Booth. "It is a beautiful looking wood, especially the extremely figured, brilliantly colored koa in the fiddleback figure." Booth said not all koa comes so highly figured, but the rare log that yields the extreme fiddleback is in high demand for architectural plywood , including airplane interiors.

"We have used koa in everything from Cessnas to the 747s for corporate jets to head-of-state aircrafts," said Booth.

Koa, he said, translates well to such uses. "It is in the same category as Brazilian rosewood or the other extremely expensive woods. The tones of koa are gorgeous - golds, blacks and reds. And when it is the extreme figure, you get a three-dimensional effect with the right finish. It gives such a visual depth of figure that it looks like something you could dive into," said Booth. "Of all the domestic woods, I would place koa near the top for beauty," he said.

Booth also gives koa high marks for workability, in the veneer form. "We have no moisture problems or checking - it is very workable. It is naturally lustrous and it takes a gorgeous finish," he said.

Al Matulevich of the David R. Webb Co. Inc. in Edinburgh, Ind., calls koa a "super attractive wood" with most of his clients requesting it for architectural woodworking. "We carry a limited amount. What we have is quartered and most of it is figured. It has some high-end furniture uses, but most is for architectural installations. It is very attractive from a figure and color standpoint. Under a high gloss finish, it is three-dimensional and quite striking."

Matulevich added that koa is somewhat underrated as an exotic. "It is really quite beautiful," he said.

Durable species
Koa is a durable wood that is resistant to insect and fungal attack and extremely resistant to preservative treatment. It dries easily with minimal degrade. The wood may have a tendency to cup, but experts recommend final conditioning in a kiln to overcome that problem. The wood has small movement in service.

Koa's average height is 70 to 80 feet, with a 10-foot trunk diameter. Koa trees are striking in appearance, with broad, round crowns and pale yellow flowers that bloom in the spring. Instead of leaves, this species has dark green, sickle-shaped phyllodes, which are petioles that take the form and function of leaves.

In his book "Know Your Woods," Albert Constantine states that koa trees made excellent dugout canoes that were capable of sailing long distances. He said the tree is so named because of its adaptability to a variety of different soil and climate conditions.

Although a beautiful wood,koa is more than an exotic veneer to the Hawaiians, Jenson said. "Hawaiians love and revere the koa tree. It is very deeply rooted in Hawaiian culture, historically and spiritually." Jensen added that there have been some attempts to grow the koa trees by tree farm, but it is too early to tell if that method will work.


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