Hawaiian hardwood ripe for commercial development

INDIGENOUS to Hawaii, ohia is Ithe dominant tree in large portions of that state's forests with large, almost pure stands in some areas. Of major importance from the standpoint of volume and acreage, it is one of the few native trees in the Islands with commercial lumber importance.

Ohia is considered excellent for strip flooring. This is its most common use in Hawaii with use as ship blocks in the drydocks at Pearl Harbor being second in importance. Other uses include as stakes to brace water barriers in irrigation ditches in the sugarcane fields. as wharf fenders, for marine construction (both treated and untreated), in pallets, for conveyor belt slats, as pile-driver cushions (circular blocks of wood placed between the hammer and concrete piles to prevent shattering) and as decorative poles in residential construction and business establishments.

Stands suitable for commercial development are found only on the Island of Hawaii. It is estimated that there is about 360 million board feet available. Trees in better stands grow to 18 to 24 inches in diameter and yield two 16 ft. logs. These stands yield from 5,000 to 6,000 board feet per acre. Timber is relatively inaccessible to logging because of the lack of roads in the rain forest.

In an effort to develop more extensive commercial use of the wood, tests of samples of ohia were done by the Forest Products Laboratory under an agreement with the Board of Commissioners of Agriculture and Forestry. These included mechanical testing for the full complement of standard tests specified by the American Society for Testing Materials.

Values indicated that ohia is the most dense and generally the strongest of any of the Hawaiian species which have been examined.

It is substantially heavier than shagbark hickory, one of the heaviest of commercial species found on the mainland. In general, it is comparable to hickory in many of its strength properties. Exceptions are its toughness, impact bending strength and strength in compression perpendicular to the grain. In these it ranks far below hickory. Ohia also has a tendency to shrink more than hickory. Its strength properties are generally higher than those of white oak.

Ohia is denser and stronger than Douglas fir, a softwood which is widely used in the Islands, but its weight, high shrinkage and dulling effect on cutting tools preclude it replacing Douglas fir for structural applications.

Many of the strength properties of ohia are not as high as would be ex-

Story at a Glance

360 million b.l. ol nalive ohia available...excellent for stdp flooring...limited additional uses...not readily accessible lor logging...some similarity lo hickory.

pected on the basis of its high density. The spiral or interlocked grain which appears to be characteristic of the species is probably responsible for this.

Veneer was successfully produed from the sample flitches being tested. It was dried in a roller<onveyor type drier without developing drying de fects. Although suitable for use as face veneer, it had drawbacks including little figure except in the burls. The interlocked grain did not produce the expectd welldefined ribbon stripe figure such as is characteristic of mahogany. The most noticeable pattern in the veneer was created by the contrast between the sapwood and the darker red-brown heartwood.

Deep knife checks and roughness requiring considerable sanding were considered other detrimental characteristics. Plywood panels were made from the veneer with no difficultY. These panels after sanding and finishing were attractive in color, but had little figure.

Machining tests showed ohia to be better in shaping and boring than most mainland hardwoods. SamPles proved poorer in planing and turning.

Ohia experienced problems in seasoning tests. It was concluded that further research would be needed in that area. Limitd previous experience with drying of l " thick ohia indicated that kiln drying of previously air dried stock is likely to give better results than kiln dryrng stock green from the saw.

Limited tests were made in pressure treating air seasoned ohia with coalt:u creosote. The results proved inconclusive because of the limits of the test. Good penetration was obtained in sapwood, but heartwood was resistant to penetration.

both our hardwood Series and past Hardvrzood

Special Issues!

Wide Appeal

Selected from vears ofour most popular hardwood articles and features, the information contained in these reprints will appear to old hands in the business as well as newcomeriwho need tiiearn fast.

Effective Training Aid

Use them as a training aid, to

Domestic Hardwoods

Hardwoods of the Pacific Northwest (19 species)

An up-to-date look at Northwest hardwoods (two parts)

A background on alder's popularity (two parts)

The Cinderella tree of the Northwest (West Coast red alder)

Western Maple

Oregon Myrtle, smooth & tough

Developing California hardwoods (black oak)

Northeastern Hardwoods (four parts) (yellow birch, hard maple, black cherry, beech, red oak, soft maple, basswood, ash, white birch, yellow poplar)

A background on walnut

Black walnut

General physical properties of Southern hardwoods (16 species)

Working with hardwoods (16 species)

Hickory's looking good (two parts)

Koa: the Royal Hawaiian hardwood

Buy brush up on facts long forgotten, or just for your own pleasure.

ASIAN.PACIFIC

Malayan Hardwoods (chart) (48 species)

Some Malayan Hardwoods (two parts) (10 species)

A quartet of related Asian Hardwoods (apitong, gurjun, keruing, yang)

The five species of meranti Ramin: a commercial light hardwood

Commercial satinwood

The romance of teak (two parts)

South American

Tropical woods from Mexico (cocobolo, goncalo alves, primavera, canalete)

More on tropical woods from Mexico (guanacaste, lingnum vitae, capomo, ebony)

Banak: a mahogany substitute

Cedro: the volatile Latin

The heavyweight and the lightweight Oignum vitae, balsa)

Two prominent Brazilian hardwoods (rosewood, jacaranda, goncalo alves)

Two varieties of brosimum

TIIIIITIIIIITIIITIIIII-T'I'

45OO Campus Drive, suite 48O Newport Beach, Ca. gp66o

Please send me the hardwood reprints checked below. I understand that if I am.not ^satisfied completely I can return them for a complete refund. I'm looking forward to reading theml

! Domestic Hardwoods $10

! Southeast Asian Hardwoods $5 n South American Hardwoods g4 n Ail three $16 (the big bargain)

! Check enclosed

! Cash enclosed