Ramin
INTRODUCTION
The Standard Malaysian Name for the timber of Gonystylus spp. (Thymelaeaceae). Vernacular names applied include ramin (Peninsular Malaysia, Sabah and Sarawak) with various epithets, dara elok (Peninsular Malaysia), the old trade name melawis (Peninsular Malaysia), pinang baik (Peninsular Malaysia) and pinang muda (Peninsular Malaysia). Major species include G. affinis, G. bancanus, G. brunnescens, G. confusus and G. maingayi. The sapwood is lighter in colour and is poorly defined from the heartwood, which is white to creamy yellow.
Also known as Ramin (Brunei); Mavota (Fiji); Medang keladi and Ramin (Indonesia); Anauan and Lanuatan bagio (Philippines); and Ainunura, Fungunigalo, Latareko and Petata (Soloman Islands).
DENSITY
The timber is a Light Hardwood with a density of 530-785 kg/m3 air dry.
NATURAL DURABILITY
The logs, as well as freshly sawn boards are very susceptible to attacks by staining fungi and powder-post beetles. The dried timber is also liable to attacks by borers. Jackson (1965) recorded that nearly all the 30 pieces of test sticks of 50 mm x 50 mm x 600 mm tested with the standard graveyard test were destroyed after one year. The timber is therefore classified as non-durable.
PRESERVATIVE TREATMENT
Ramin is extremely easy to treat with preservatives.
TEXTURE
Texture is moderately fine and even, with shallowly interlocked grain.
STRENGTH PROPERTIES
The timber falls into Strength Group C (Engku, 1988b) or SG5 (MS 544:Part 2:2001).
Strength Properties of Ramin (G. bancanus)
|
Test
Condition |
Modulus of Elasticity (MPa) |
Modulus of Rupture (MPa) |
Compression parallel to grain (MPa) |
Shear Strength (MPa) |
|
Green |
14,200 |
62.0 |
35.0 |
7.2 |
|
Air dry |
15,900 |
88.0 |
48.8 |
8.5 |
MACHINING PROPERTIES
It is easy to saw, cross cut and plane and the surfaces produced are smooth. The timber is easy to bore but the finish is rough.
Machining Properties of Ramin (G. bancanus)
|
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 |
|
Green |
easy |
easy |
easy |
smooth |
easy |
rough |
- |
- |
|
Air dry |
easy |
easy |
easy |
smooth |
easy |
rough |
easy |
smooth |
NAILING PROPERTY
The nailing property is rated as poor, but the resistance to splitting will be improved if the nails used are clinched.
AIR DRYING
The timber seasons fairly slowly, with moderate cupping, bowing, surface-checking and staining as the main sources of degrade. 13 mm thick boards take 3.5 months to air dry, while 38 mm thick boards take 4 months.
KILN-DRYING
Kiln Schedules B and C are recommended. Timbers of more than 40 mm in thickness are prone to surface checking and end-splitting and the milder Schedule B is more suitable.
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 |
80.0 |
118 |
47.5 |
50 |
Kiln Schedule C
|
Moisture Content
(%) |
Temperature
(Dry Bulb) |
Temperature
(Wet Bulb) |
Relative Humidity (%) |
|
° F |
° C |
° F |
° C |
|
Green |
105 |
40.5 |
101 |
38.0 |
85 |
|
60 |
105 |
40.5 |
99 |
37.0 |
80 |
|
40 |
110 |
43.5 |
102 |
39.0 |
75 |
|
35 |
110 |
43.5 |
100 |
38.0 |
70 |
|
30 |
115 |
46.0 |
103 |
39.5 |
65 |
|
25 |
125 |
51.5 |
109 |
43.0 |
60 |
|
20 |
140 |
60.0 |
118 |
47.5 |
50 |
|
15 |
150 |
65.5 |
121 |
49.0 |
40 |
SHRINKAGE
Shrinkage is high, especially in the tangential direction. Radial shrinkage averages 1.6% while tangential shrinkage averages 3.4%.
DEFECTS
The logs are generally free from natural defects, but are liable to staining fungi and insect attacks. Included phloem of the foraminate type sometimes occur in the wood of G. maingayi. Large trees may have a central core of up to 150 mm in diameter where the wood is streaked with stripes of dark brown or black. Other defects noted include shot holes.
USES
The timber has established a reputation as a first class joinery timber. The timber is also suitable for furniture, panelling, mouldings, cabinet making, flooring, staircase (baluster, balustrade, carriage, handrail, riser, stringer, thread, bullnose, round end and winder), post, beams, joists, rafters, door and window frames and sills (internal use only), cooling tower (non-structural members), plywood, handles for non-striking tools, pencil and ornamental items.
REFERENCES
-
Engku, Abdul Rahman Chik. 1988b. Basic And Grade Stresses For Some Malaysian Timbers. Malayan Forest Service Trade Leaflet No. 38. The Malaysian Timber Industry Board And Forest Research Institute Malaysia, Kuala Lumpur. 13 pp.
-
Jackson, W. F. 1965. The Durability of Malayan Timbers. Mal. For. Ser. Trade Leaflet No.28.
- 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 Insitute Malaysia, Kuala Lumpur. 48 pp.
-
MS 544: Part 2: 2001: Code Of Practice For Structural Use Of Timber. Permissible Stress Design of Solid Timber.
-
Sim, H. C. 1983. Malaysian Timbers - Ramin. Malaysian Forest Service Trade Leaflet No. 74. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur. 8 pp.
-
Wong, T. M. 1982. A Dictionary of Malaysian Timbers. Revised by Lim, S. C. & Chung, R. C. K. Malayan Forest Record No. 30. Forest Research Institute Malaysia, Kuala Lumpur. 201 pp.
