TEAK
BOTANICAL NAME: Tectona Grandis of the family Verbenaceae

COMMON NAMES: the main common names for this species are teak and genuine teak. My database lists more than 80 other names, including: kyan (Burma), teck (French), teca (Spanish), burma teak, rangoon teak, moulmein teak, gia thi, jati sak, kyun, mai sak, rosawa, and many other local names.

TYPE: hardwood

COLOR: pale yellow/tan sapwood is sharply demarcated and easily distinguished from the heartwood which ranges from rich reddish-brown to greenish-brown, sometimes golden brown, sometimes dark brown. Heartwood darkens with exposure. Heartwood sometimes has darker markings.

GRAIN: straight to wavy grain, sometimes fairly striking, but pieces can be found with a subdued grain pattern.

Growth rings are distinct, but they vary considerably from a band of two or three layers of large pores to a few scattered large pores not forming a definite band. The dark-coloured parenchyma initiating the seasons growth likewise varies in its width and presence. Teak from some localities may display not only annually occurring growth rings, but also occasional false rings, with very little initial dark parenchyma, with the result that much teak, especially from Burma, is relatively uniform in colour but with only very narrow lines of darker colour marking the annual growth appearing on side grain.

TEXTURE: medium to coarse texture, very fibrous, sometimes uneven, and usually oily to the touch

PROPERTIES / WORKABILITY: A fairly heavy and dense wood that can be hard to glue due to the oily nature and is very tough on cutting edges due to high silica content. Glues best when freshly planed or sanded. Turners, in particular, are likely to be frustrated by the exteme dulling of turning tools. Planes well, molding characteristics are good, drills well, routes well (but again, silicone can cull cutting edges), good carving properties, takes nails and screws well but predrilling is recommended, and sands reasonably well although the silicone content can be a problem.

DURABILITY: The heartwood is extremely resistant to decay, fungi, and termites but not to marine borers. Resists wear, denting, and marring fairly well. The heartwood is reported to extremely resistant to preservative penetration. The sapwood is also of low permeability. Good acid resistance.

FINISH: Stains well and takes a satisfactory finish, especially an oil finish and can be varnished or polished satisfactorily.

STABILITY: very low movement in service

BENDING: moderate to high bending strength

ODOR: strong sweet scent when freshly cut

SOURCES: indigenous to India, Burma, Thailand, and to the former Indo-China, ie Cambodia, Laos, and Vietnam, and in Indonesia, particularly Java, although strictly speaking, teak was introduced into Java originally, and was planted near temples and shrines. Over several centuries these original plantings have extended and developed into almost pure timber stands over fairly extensive areas. Teak is not normally gregarious in its natural habitat, usually being found in mixed deciduous forests. Also grown in Guyana, Haiti, Jamaica, Mexico. Panama, Peru, and tropical africa.

USES: widely used for high end sail-boat decks due to two things: (1) its resistance to fading due to saltwater and sunlight and its ready acceptance of a chemical treatment that brings back the natural beauty once it DOES suscumb to the salt and sun, and (2) the fact that it does not promote rusting of contiguous metal fittings.

Also used for shipbuilding, planking, deck-houses, bulwarks, furniture. cabinet-making, interior fittings and panelling, out-door building and furniture, laboratory benches and equipment, acid vats, weather doors, plywood and decorative veneer, joinery, furniture, flooring, carving, cabinetwork, paneling, turnery, tanks and vats, fixtures requiring high acid resistance, and heavy construction.

TREE: The tree is reported to grow to heights of 130 to 150 ft (45m). With clear boles to 90 ft (30m)) with trunk diameters of 36 to 60 inches (1.55m). Trunks are fluted and buttressed in older trees. In its natural habitat, teak is often a large tree, with a clean, cylindrical bole above a fluted or often buttressed base. It can vary considerably in height, girth and form, according to locality, particularly in regard to soil conditions. On clay soils it does not do well, and in the drier and hotter regions. the trees often have much shorter and more fluted stems, with more twisting and branching. On favourable sites, it can reach a height of 39m to 45m and a diameter of 1.5m with a clear bole of 10m up to 24m.

WEIGHT: about 50 pounds per cubic foot

DRYING: teak from ring-girdled trees air dries easily but slowly, but timber from ungirdled. green trees requires a lot of initial care in order to avoid rapid drying which is liable to cause checking. end splitting and warping to develop. Teak presents no serious problems in kiln drying from the air dry condition, except in the assessment of initial and final moisture contents. While drying defects are usually minimal, there is usually considerable variation in the drying rate of individual pieces, and moisture content differences can be great.

reported to air-season rather slowly with little or no degrading.

AVAILABILITY: high

COST: moderate to expensive

OTHER NOTES:

I have read that harvesting teak is complicated by the fact that green teak won't float so trees have to be girdled and left dead for up to three years before they are dry enough to be harvested and floated downriver to sawmills. Also, their leaves are reportedly so abrasive that they are used locally as sandpaper.

numerous reports warn of skin and/or eye irritation

web quotes:
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There is often a loss of colour in some pieces in kiln drying, but the colour is quickly regained when the wood is exposed to light.

On boats, exposed raw teak becomes grey in only a few months but there are many commercial preparations which will restore it to its natural beauty.

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Sanding the butt-end of a teak plank is just as difficult as sanding a similar piece of purpleheart, but more due to the fibrous nature of teak than the density of purpleheart. Whereas purpleheart sands relatively more easily against the grain than with the grain, teak is hard to sand in any direction because of its fibrous nature.

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Indian teak, especially from the Malabar Coast, (with its heavy annual rainfall) is usually more handsomely marked. The wood has an oily feel, and a strong odour reminiscent of old leather when freshly cut, but after drying much of the odour is lost, but the wood retains its oily feel.