MENGKULANG/KEMBANG
INTRODUCTION
The Standard Malaysian Name for the light timber of Heritiera spp. (Sterculiaceae). Vernacular names applied include mengkulang (Peninsular Malaysia) with various epithets, jambu keluang (Melaka), kembang (Sabah), melabu (Sarawak) and melima (Peninsular Malaysia). Major species of the timber include H. albiflora, H. aurea, H. borneensis, H. globosa, H. javanica, H. simplicifolia and H. sumatrana. The sapwood is usually lighter in colour than the heartwood and not always sharply defined from the heartwood, which is red, red-brown to dark red-brown.
Also known as Red or brown tulip oak (Australia); Bey samlek and Don chem (Cambodia); Mengkulang (Brunei); Sundri (India); Mengkulang, Palapi and Teraling (Indonesia); Hao (Laos); Kanazo (Myanmar); Lumbayao (Philippines); Chum-praek and Chumprak (Thailand); and Huynh (Vietnam).
DENSITY
The timber is a Medium Hardwood with a density of 625-895 kg/m3 air dry.
NATURAL DURABILITY
This timber is not durable if used in contact with the ground as it is very susceptible to damage by termites and is liable to fungal infestation. It is however, perfectly satisfactory for use in reasonably dry, well ventilated positions that are free from termite attacks. Test sticks treated by the full cell process with an average absorption of 119 kg/m3 (7.4 lb/ft3) was found to be serviceable after 13 years.
PRESERVATIVE TREATMENT
It is not a difficult timber to treat with preservatives and is classified as "average".
TEXTURE
Texture is slightly to moderately coarse but even, with straight to shallowly interlocked grain.
STRENGTH PROPERTIES
The timber falls into Strength Group B (Engku, 1988b) or SG 5 (MS 544:Part 2:2001).
| Strength Properties of Mengkulang | ||||||
|---|---|---|---|---|---|---|
| Species | Test Condition | Modulus of Elasticity(MPa) | MModulus of Rupture(MPa) | Compression parallel to grain (MPa) | Compression perpendicular to grain (MPa) | Shear strength (MPa) |
| H. javanica | Green | 10,600 | 68 | 31.8 | 4.21 | 9.9 |
| Air dry | - | - | - | - | - | |
| H. simplicifolia | Green | 13,700 | 75 | 37.8 | 3.86 | 8.2 |
| Air dry | 15,990 | 91 | 52.1 | 5.38 | 10.8 | |
MACHINING PROPERTIES
It is difficult to saw and is slightly difficult to plane. However, a smooth finish can be produced.
| Machining Properties of Mengkulang | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Species | Test Condition | Sawing | Planing | Boring | Turning | ||||
| Re-sawing | Cross Cutting | Ease of planing | Quality of finish | Ease of boring | Quality of finish | Ease of turning | Quality of finish | ||
| H. javanica | Green | difficult | difficult | slightly difficult | smooth | slightly difficult | rough | - | - |
| Air dry | difficult | difficult | slightly difficult | smooth | difficult | moderately smooth | easy | slightly rough | |
| H. simplicifolia | Green | slightly difficult | slightly difficult | easy | smooth | slightly difficult | moderately smooth | - | - |
| Air dry | difficult | difficult | easy | smooth | difficult | moderately smooth | easy | slightly rough | |
NAILING PROPERTY
Nailing property is rated as good.
AIR DRYING
The timber seasons fairly rapidly with slighht cupping, end-checking and surface-checking as the main defects. 13 mm thick boards take 2 months to air dry, while 38 mm thick boards take 3 months.
KILN-DRYING
Kiln Schedule D is recommended. 25 mm thick boards take approximately 7 days to kiln-dry.
| Kiln Schedule D | |||||
|---|---|---|---|---|---|
| Moisture Content (%) | Temperature (Dry Bulb) | Temperature (Wet Bulb) | Relative Humidity (%) (approx.) | ||
| °F | °C | °F | °C | ||
| Green | 105 | 40.5 | 101 | 38.0 | 85 |
| 60 | 105 | 40.5 | 99 | 37.0 | 80 |
| 40 | 105 | 40.5 | 96 | 35.5 | 70 |
| 35 | 110 | 43.5 | 97 | 36.0 | 60 |
| 30 | 115 | 46.0 | 97 | 36.0 | 50 |
| 25 | 125 | 51.5 | 101 | 38.0 | 40 |
| 20 | 140 | 60.0 | 105 | 40.5 | 30 |
| 15 | 150 | 65.5 | 112 | 44.5 | 30 |
SHRINKAGE
Shrinkage is high. Radial shrinkage averages 1.5% while tangential shrinkage averages 3.4%.
DEFECTS
The logs are generally free from defects.
USES
The timber is suitable for medium construction, decorative works, superior joinery, cabinet making, interior finishing, panelling, mouldings, general planking, furniture, plywood, flooring, decking, staircase (angle block, rough bracket, baluster, balustrade, carriage, handrail, riser, stringer, tread, bullnose, round end and winder), vehicle bodies (framework, floor boards and planking), ship and boat building (keels, keelsons, framework and general planking), railway sleepers, piling, cooling tower (structural members), door and window frames and sills, posts, beams, joists, rafters, telegraphic and power transmission posts and cross arms, glulam works, pencil and pallets (heavy duty and permanent type).
REFERENCES
- Engku Abdul Rahman Chik. 1998b. Basic and Grade Stresses for Strength Groups of Malaysian Timbers. Malayan Forest Service Trade Leaflet No. 38. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur.13 pp.
- Lopez, D. T. 1981. Malaysian Timbers - Mengkulang. Malaysian Forest Service Trade Leaflet No. 47. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur. 7 pp.
- Menon, P. K. B. 1986. Uses of Some Malaysian Timbers. Revised by Lim, S. C. Timber Trade Leaflet No. 31. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur. 48 pp.
- MS 544:Part 2:2001. Code of Practice for the Structural Use of Timber: Permissible Stress Design of Solid Timber.
- 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.