August 14, 2011 | 5:08 pm CDT


  Wood of the Month:
Jelutong Popular with Carvers,
Sculptors and Patternmakers

By Jo-Ann Kaiser

Dyera costulata of the family Apocynaceae

Jelutong, jelutong bukit, jelutong paya

Trees grow to 200 ft or higher with diameters of 5 to 6 ft and boles clear and straight for 90 ft. Average weight is 29 lbs per cubic ft, with a specific gravity of 0.46.

Wood has medium density, low stifness and bending and crushing strengths. It dries easily, usually without problems, although staining can occur. The wood has a poor steam bending rating. It works well with hand or machine tools, although gum can pose problems on cutting surfaces. Wood glues, screws and nails well. It stains, paints and varnishes very well. The wood has a slight sour odor, is non-durable and subject to attack by powder post beetles. However, it can be treated with preservatives.

Jelutong (jel·u·tong), is a tall hardwood tree that grows in Malaysia, Borneo and Sumatra. It grows rapidly and has many commercial timber uses, but it is equally well known for its by-product, latex.

The wood from jelutong is very light in color, ranging from a creamy white to pale yellow and has a plain, straight grain and even texture. Albert Constantine Jr., writing in the book Know Your Woods, said the wood has a plain appearance and is off-white when first manufactured, with no difference between the sapwood and heartwood. "After exposure to the air it has a yellowish tint."

Attributes such as low density, ease of workability, plain grain and fine texture have made it extremely popular with carvers and patternmakers. Sean Patton, manager of U.S. products, Freeman Manufacturing and Supply Co., in Avon, OH, says his company has sold jelutong for some time. "We supply wood and other materials to pattern, model and prototype industries. Jelutong’s fine texture, stability, ease of workability and moderate price makes it a popular choice for patternmaking."

Patton says other woods his company sells for patternmaking include mahogany and pine. "Jelutong rates in the middle between mahogany and the pines for price."

Patton also says the way jelutong is worked is changing. "People in the pattern making industries are switching to CNC machinery to do work that was formerly done by skilled workers. Jelutong works equally well with hand or machine tools. Jelutong is ideal for pattern shop applications as well as fine, detailed work and intricate carving."

Jelutong has about the same properties as sugar pine, Patton says. He says jelutong accepts pattern coatings very well.

Uses Vary
The list of uses for jelutong is fairly long. It is an excellent choice for sculpting and carving. It is also used to make architectural models, drawing boards, picture frames, wooden shoes (clogs), furniture parts, doorknobs, dowels and pencils.

Jelutong is rotary cut for corestock for flush doors, plywood and laminated boards. It is used to make toys, dowels, blackboards, brush handles, matchsticks and packing crates.

Extracting Latex
Jelutong is one of many trees tapped for material that is used as a base for chewing gum. The latex in the wood is extracted by a process known as tapping — cutting v-shaped grooves into the standing, live tree with knives. The latex is collected, usually in containers made from bark, and goes through further processing as gum is made. The latex is also used in paints and for sizing paper. Tapping begins when a tree is young. As a tree matures, additional cuts or taps will be made. Tapped trees may be stained from a fungus.

Kiln Drying
The wood dries easily with few problems. Patton says his company kiln dries its boards to less than 12 percent moisture, then stores them in heated warehouses to maintain moisture content and overall quality.

Suggested kiln schedule for drying is T10-D4S for 4/4 stock and T8-D3S for 8/4 stock. Experts recommend proper air circulation when the material is air-dried. Thick stock can be hard to dry without the material staining. Movement in service is rated "small."

Editors of Encyclopedia of Wood say jelutong wood is "very lustrous, but contains slit-like radial latex passages on tangential surfaces, in clusters or rows about 3 feet apart. These passages, or canals, which appear lens-shaped on flat-sawn surfaces, about 1/4 in. wide and 12 in. long, rule out the possibility of using jelutong where sizable pieces are required or where appearance is important." The defects can be eliminated in conversion.

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