Yemane

INTRODUCTION

A common name for the timber of Gmelina arborea (Verbenaceae). The species was introduced into Peninsular Malaysia in 1920 as plantation timber species. The sapwood of the timber is lighter in colour but not clearly distinct from the heartwood, which is straw-yellow to creamy white, turning to reddish brown with age.

Also known as Toeah (Australia), Gamari and Gumhar (India); Kayu titi (Indonesia); Mai so (Laos); Mai saw, Yemane and Yemani (Myanmar); Etdemata (Sri Lanka); and Gumari, Saw, So and So-maeo (Thailand).


DENSITY

The timber is light and soft with an average density of 408 kg/m3 air dry.


NATURAL DURABILITY

The timber is non-durable under exposed conditions. However, it has been reported that in Myanmar, house posts of yemane were still sound after 30 years of service (in Malaysia, average service life in exposed conditions is 1.3 years). Tests in the United Kingdom showed that the heartwood was moderately durable with respect to fungal attacks. In India, the timber of Gmelina was found to be susceptible to marine borers.


PRESERVATIVE TREATMENT

It is generally difficult to treat the heartwood of Gmelina with preservatives by the normal pressure process. Even sapwood is moderately resistant.


TEXTURE

Texture is moderately coarse but even. Grain is straight, moderately interlocked or wavy.


STRENGTH PROPERTIES

The timber is moderately strong (with strength value fairly similar to meranti tembaga - Shorea leprosula).


MACHINING PROPERTIES

The timber is easy to resaw and cross-cut. Planing, boring and turning are easy with smooth finishing. The logs are easy to peel by rotary peeling even without pre-treatment.


NAILING PROPERTY

Nailing property is rated as excellent.


AIR DRYING

The timber dries very slowly with very few degrades except with some slight cupping, bowing, staining and moderate end-checking. 13 mm thick boards take 3.5 months to air dry, while 38 mm thick boards take about 10 months.


KILN-DRYING

Kiln Schedule K is recommended for kiln-dyring.


SHRINKAGE

Shrinkage is low. Radial shrinkage ranges 0.5-0.6% while tangential shrinkage is about 1.1%.


USES

The timber is widely used as furniture wood in Sierra Leone due to its light colour, stability and good working properties. Tests in Nigeria indicated that yemane is suitable for match splints. In India, the timber is used for the manufacture of furniture, panelling, packing boxes and crates, musical instruments, railway carriages and building. The timber can also be used for decking, mouldings and general carpentry works.


REFERENCE

  1. Wong, T. M. 1982. A Dictionary of Malaysian Timbers. Revised by Lim, S. C. & Chung, R. C. K. Malayan Forest Records No. 30. Forest Research Institute Malaysia, Kuala Lumpur. 201 pp.