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

  1. 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.
  2. Jackson, W. F. 1965. The Durability of Malayan Timbers. Mal. For. Ser. Trade Leaflet No.28.
  3. 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.
  4. MS 544: Part 2: 2001: Code Of Practice For Structural Use Of Timber. Permissible Stress Design of Solid Timber. 
  5. 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.
  6. 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.