Mengkulang


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)

Modulus 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

Rip-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

  1. 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.
  2. 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.
  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 Institute Malaysia, Kuala Lumpur. 48 pp.
  4. MS 544:Part 2:2001. Code of Practice for the Structural Use of Timber: Permissible Stress Design of Solid Timber.
  5. 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.