Damar Minyak

INTRODUCTION

The Standard Malaysian Name for the timber of Agathis spp. (Araucariaceae). Vernacular names applied include bindang (Sarawak), bulok (Sarawak), bulu (Sarawak), kayu jadi (Sarawak), Malayan kauri (Peninsular Malaysia), manggilan (Sabah), Sabah agathis (Sabah), salang (Sabah), tumu (Sarawak), tangilan (Sabah), tungilan (Sabah), tubu (Sarawak) and tumuh (Sarawak). Major species include A. borneensis, A. endertii, A. flavescens, A. kinabaluensis, A. lenticula and A. orbicula. The sapwood is not differentiated from the heartwood, which is buff or cream, sometimes with a pink tinge and darkens into a light golden brown.

Also known as Kauri (Australia); Tulong (Brunei); Ndaku (Fiji); Agathis, Bembueng, Dammar pilau, Dammar raja, Fuko, Goga, Hedje, Kayu dammar putih, Kessi, Kisi, Salo and Solo (Indonesia); Kauri and Kauri pine (New Zealand); Kauri pine (Papua New Guinea); and Almaciga and Dayungon (Philippines).


DENSITY

It is a Softwood timber with a density of 360-660 kg/m3 air dry.


NATURAL DURABILITY

The timber is non-durable under exposed conditions. The timber is subject to dry-wood termite attacks and is rapidly destroyed by rotting fungi. The timber is however immune to powder-post beetles attack. Damar minyak treated with creosote to an average absorption of 630 kg/m3 (39.4 Ib/ft3) showed great durability when tested. Forty test sticks were buried in 1965 and all of these sticks are still sound after 15 years of burial.


PRESERVATIVE TREATMENT

The timber is classified as extremely easy to treat.


TEXTURE

Texture is very fine and even, with straight grain.


STRENGTH PROPERTIES

The timber falls into Strength Group D (Engku, 1988b) or SG 6 (MS 544:Part 2:2001).


Strength Properties of Damar Minyak

Test Condition

Modulus of Elasticity (MPa)

Modulus of Rupture (MPa)

Compression parallel to grain (MPa)

Compression perpendicular to grain (MPa)

Shear Strength (MPa)

Green

10,500

43

22

-

7

Air dry

12,000

65

34

-

7


MACHINING PROPERTIES

The timber is easy to resaw and cross-cut. Planing is easy and the planed surface is smooth and lustrous.


NAILING PROPERTY

Nailing property is rated as excellent.


AIR DRYING

The timber seasons fairly slowly with slight cupping, bowing, end-checking, splitting, insect and fungal attacks as the main sources of degrade. 13 mm thick boards take approximately 2 months to air dry, while 38 mm thick boards take 5 months.


SHRINKAGE

Shrinkage is moderate, with radial shrinkage averaging 1.2% and tangential shrinkage averaging 2.5%.


MOVEMENT IN SERVICE

The movement of seasoned timber is classified under Type I.


DEFECTS

The logs are generally remarkably free from defects except for occasional shot holes which are evenly distributed. Spiral grains have been recorded, although only on rare occasions.


USES

The timber is highly prized as an interior finishing timber and is suitable for panelling, mouldings, high class joinery, pencil, plywood, furniture, drawing boards, disposable chopsticks, tooth picks, pattern-making and staircase (apron linings, handrail and sprandrel framing).


REFERENCES

  1. Engku Abdul Rahman Chik. 1988b. 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. 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.
  3. MS 544:Part 2:2001. Code of Practice for the Structural Use of Timber: Permissible Stress Design of Solid Timber.
  4. Wong, T.M. 1981. Malaysian Timbers - Damar Minyak. Timber Trade Leaflet No. 43. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur. 5 pp.
  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.