The timber is a Heavy Hardwood with a density of 865-1,220 kg/m3 air dry. The timber has been classified as very durable
The Standard Malaysian Name for the heavy timbers of Hopea spp. (Dipterocarpaceae). Vernacular names applied include giam (Peninsular Malaysia) with various epithets, selangan (Sabah and Sarawak) with various epithets and other localised names too numerous to list here. Major species include H. ferrea, H. helferi, H. nutans, H. pentanervia and H. semicuneata. The sapwood is yellow and is poorly defined from the heartwood, which is yellow with a greenish tinge when fresh and turns deep red-brown on exposure.
Also known as Balau (Indonesia); Heavy hopea (Papua New Guinea); Hin, Mai khaen fay and Mai la en (Laos); Koki:r (Cambodia); Krabok-krang, Lao Tao, Takian Hin, Takian-Nu and Takian-rak (Thailand); Sao xanh (Vietnam); Saplungan and Yakal(Philippines); Thingyan (Myanmar).
AIR DRYING
The timber seasons very slowly, with only slight end-checking, splitting and surface-checking as the main sources of degrade. 13 mm thick boards take approximately 6 months to air dry, while 38 mm thick boards take 8 months.
KILN DRYING
Kiln Schedule B is recommended.
Kiln Schedule B
|
Moisture Content (%) |
Temperature(Dry Bulb) |
Temperature(Wet Bulb) |
Relative Humidity (%) (approx.) |
||
|
° F |
° C |
° F |
° C |
||
|
Green |
105 |
40.5 |
101 |
38.0 |
85 |
|
40 |
105 |
40.5 |
99 |
37.0 |
80 |
|
30 |
110 |
43.5 |
102 |
39.0 |
75 |
|
25 |
115 |
46.0 |
105 |
40.5 |
70 |
|
20 |
130 |
54.5 |
115 |
46.0 |
60 |
|
15 |
140 |
60.0 |
118 |
47.5 |
50 |
SHRINKAGE
Shrinkage is average to high, with radial shrinkage ranging 1.4-2% and tangential shrinkage ranging 2.6-4.4%.
