White Seraya
INTRODUCTION
The Standard Malaysian Name for the timber of the lighter species of Parashorea (Dipterocarpaceae). This timber is confined to the states of Sabah and Sarawak. Vernacular names applied include urat mata (Sabah and Sarawak) with various epithets. Major species include P. malaanonan and P. tomentella. The sapwood is paler in colour and not clearly defined from the heartwood, which is pinkish cream when fresh, turning to straw-colour or light brown on exposure.
Also known as White Seraya (Brunei); Pendan, Penden, Tembalun and Urat mata (Indonesia); and Bagtikan, Light Red Philippines, Mahogany, Malaanonang and White lauan (Philippines).
DENSITY
The timber is a Light Hardwood with a density of 400-655 kg/m3 air dry.
NATURAL DURABILITY
It is non-durable.
PRESERVATIVE TREATMENT
The timber is difficult to treat with preservatives.
TEXTURE
Texture is moderately coarse and even with interlocked grain.
STRENGTH PROPERTIES
The timber falls into Strength Group C (Burgess, 1958).
MACHINING PROPERTIES
It is fairly easy to work although it has a dulling effect on the tools. The planed surface of tangential boards is smooth, but on the radial boards, there is a tendency for tearing of grain.
AIR DRYING
The timber dries moderately slowly to slowly and is subject to warping and checking and also staining by fungi. 25 mm thick boards take approximately 5.5 months to air dry.
KILN-DRYING
Kiln Schedule J is recommended. The timber is reported to season fairly rapidly with minimum defects except for some cupping.
Kiln Schedule J
Moisture Content (%) |
Temperature (Dry Bulb) |
Temperature (Wet Bulb) |
Relative Humidity (%) (approx.) |
||
� F |
� C |
� F |
� C |
||
Green |
135 |
57.0 |
123 |
50.5 |
70 |
50 |
135 |
57.0 |
119 |
48.0 |
60 |
40 |
140 |
60.0 |
118 |
47.5 |
50 |
30 |
150 |
65.5 |
121 |
49.0 |
40 |
20 |
170 |
76.5 |
127 |
53.0 |
30 |
