Koa: Tree Soldiers On for Furniture & Musical Instruments
By Jo-Ann Kaiser | Posted: 11/29/2012 8:00AM
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Acacia koa of the Family Fabaceae (Leguminosae)
Koa, acacia koa, red koa, yellow koa, Hawaiian mahogany
Trees can grow to 115 feet or more, with average heights ranging from 49 to 82 feet depending on location. Average weight is 41 pounds per cubic foot, with a specific gravity of 0.67.
• The wood dries easily with little degrade. It works fairly well with machine and hand tools. Experts recommend sharp cutting edges due to the wood’s moderate blunting effect.
• Koa has a medium ending strength and stiffness, high crushing strength plus good resistance to shock loads.
• The wood has small movement in service. Vibrant, colorful koa, from the species Acacia koa, is one of our more exotic domestic species and to many a national treasure. Endemic to Hawaii, it grows on all of the major Hawaiian Islands including Kauai, Oahu, Molokai, Maui, Lanai and Hawaii.
The wood has a storied past. Considered by many to be Hawaii’s most important commercial timber, koa is also described as being important to Hawaii’s ecology, economy and culture. “Koa trees in natural ecosystems provide habitat for many birds, insects and plants, some endangered,” says the University of Hawaii’s Forestry Extension Service. “As a nitrogen-fixing species, koa plays an important role in forest fertility.”
Unfortunately, koa’s population has been damaged by a variety of factors including cattle grazing, logging, insects and rats, which strip the bark from immature trees. Hawaii is proactive with programs for protective measures, including harvesting of the trees as well as replanting.
The Hawaiian Legacy Reforestation Initiative is one such program. According to the group’s website, “Through the Hawaiian Legacy Reforestation Initiative, Hawaiian Legacy Hardwoods is working with individuals and organizations in an effort to restore 1,000 acres of koa forest on the Hamakua Coast of Hawaii Island.” HLH is using seeds from some of the old growth koa trees as a source for the new trees, known as Legacy Trees.
Myriad of Uses
From Fogelvik Furniture, “The Lava Fountain” features curved legs that are bent-laminated and veneered with dark curly koa. Photo: Hal Lum At one time, the primary use of the timber was for canoes, including giant war canoes spanning 70 feet. The Forestry Extension Service notes an increasing interest in “Hawaiian voyaging and racing vessels using traditional materials has led to a greater public awareness of the scarcity of trees suitable for ‘canoe koa’ and the importance of renewing this depleted resource.”
Another well-known use for koa is the ukulele and it is equally popular with guitar makers. In addition to being visually interesting, koa has resonant properties.
Brian Hearne, president of Hearne Hardwoods in Oxford, PA, said koa is a special wood. “Of the 150 to 185 woods we carry, koa is the most colorful. Koa can go from gold to black in the same board. Every log has different color combinations, with gold, yellow, red, violet, brown, black streaks and more a possibility.
“That is the charm with koa,” Hearne added. “You just never know what a log will yield.”
However, he noted, it can be one of the more expensive species due to demand and supply. “Basically, it only grows in Hawaii in what amounts to a very small part of the world.”
From Fogelvik Furniture, the koa coffee tables feature matching tabletops, cut in sequence from the log. Photo: Mats Fogelvik. In addition to musical instruments and canoes, koa tends to be used in high-end furniture and cabinetry, yachts, architectural paneling, and specialty items such as knife handles and pool cues. “It isn’t just for interiors. The wood famous for making Polynesian war canoes is well known as an excellent outdoor wood and it is great to work,” Hearne said.
“When I design a piece, I think of it as sculpture in the format of furniture,” said Robert Lippoth, owner of Robert Lippoth Studio Works in Maui. The studio woodworker specializes in custom koa furniture as well as pieces using other native Hawaiian woods.
At Fogelvik Furniture, located in Maui and on the Big Island, Swedish native Mats Fogelvik has been working with koa for more than 15 years. His specialty is custom furniture and interior woodwork as well as studio furniture, for sale and display in galleries.
With his main medium koa, Fogelvik said the highly figured wood is the most desirable for high-end uses. It has weight and strength properties similar to black walnut, is stable and works well. Finished with oils, varnish or lacquer, koa yields a beautiful, rich finish, Fogelvik added.
About the Author
Jo-Ann KaiserJo-Ann Kaiser has been covering the woodworking industry for 31+ years. She is a contributing editor for the Woodworking Network and has been writing the Wood of the Month column since its inception in 1986.