DYERA COSTULATA

Distribution
Sumatra and Borneo, including Sarawak and Sabah.

The tree
Species of Dyera are large trees, up to 60m in height and 1m or more in diameter, with straight, cylindrical unbuttressed boles, often 27,5m long.

The timber
A plain wood, uniformly white or straw-coloured throughout, although sometimes discoloured by staining fungi. The grain is graight and the texture fine and even. Jelutong is a light hardwood, average density about 0,46, i.e., about the same weight as poplar. Its appearance is marred by the presence of slit-like latex traces.

Strength
A light-weight wood, jelutong is correspondingly low in strength. On average it is from 25-40% weaker than light-red meranti or light-red seraya in bending strength, compression, stiffness and shock resistance.

Durability
Jelutong is rated non-durable when exposed to fungal attack. It is particularly susceptible to termite attack and the sapwood, although not visually distinct from the heartwood, is very liable to stain and to damage by wood-boring insects. The wood is readily treated with preservatives.

Working qualities
Jelutong presents no difficulty in working with either machine or hand tools. It has little dulling effect and provided that cutting edges are kept sharp it takes an excellent finish. It nails and screws well and can be glued satisfactorily.

Uses
By reason of its fine, even texture, good working properties and stability, jelutong has been found acceptable, as an alternative to the more expensive yellow pine, for engineers’ patterns and drawing boards. It is popular for model making and handicraft work and has been used for joinery.