Turpentine

Scientific name

Syncarpia glomulifera. Family: Myrtaceae.

Local names

Luster, red luster.

Description and natural occurrence

A large tree reaching about 40 to 45 m in height and 1.0 to 1.3 m in stem diameter. The trunk is straight, of good form with little taper. The foliage forms a compact, narrow, shady crown. The undersides of the leaves are coated with a silver-grey down. The bark, which is persistent over the trunk and branches, is thick, fibrous and stringy with deep longitudinal furrows. It is brown or reddish brown in colour. The species name is derived from the small amount of oleoresin in the inner bark.

This species occurs along the eastern coast of Australia from Bateman´s Bay, New South Wales, to Cooktown, North Queensland. Best development in the tropics is on elevated sites.

Sawn timber of this species is fairly readily available.

Wood appearance

Colour. The heartwood ranges from deep red to red-brown. Sapwood is paler.

Grain. Fine to medium textured but often wavy; grain often interlocked. The species is free from gum veins.

Wood properties

Density. 945 kg/m3 at 12% moisture content; approximately 1.0 m3 of seasoned sawn timber per tonne.

Strength groups. S3 unseasoned; SD3 seasoned.

Stress grades. F8, F11, F14, F17 (unseasoned), F14, F17, F22, F27 (seasoned), when visually stress graded in accordance with AS 2082-1979, Visually stress-graded hardwood for structural purposes.

Joint groups. J2 unseasoned; JD1 seasoned.

Shrinkage to 12% MC. 13.0% (tangential); 6.5% (radial).

Unit shrinkage. 0.35% (tangential); 0.23% (radial). These values apply to timber reconditioned after seasoning.

Durability above-ground. Class 1 - life expectancy over 40 years.

Durability in-ground. Class 2 - life expectancy 15 to 25 years.

Lyctine susceptibility. Sapwood not susceptible to lyctine borer attack.

Termite resistance. Resistant.

Preservation. Sapwood readily accepts preservative impregnation but penetration of heartwood is negligible using currently available commercial processes.

Seasoning. Care is needed in seasoning this species because of a tendency to collapse and distort.

Hardness. Very hard (rated 1 on a 6 class scale) in relation to indentation and ease of working with hand tools.

Machining. Can be abrasive to machine cutters and tools due to the presence of silica in the wood.

Fixing. No difficulty has been experienced with the use of standard fittings and fastenings.

Gluing. As with most high-density species, machining and surface preparation should be done immediately before gluing.

Finishing. Will readily accept paint, stain and polish.

Uses

Engineering. As sawn and round timber in wharf and bridge construction, railway sleepers, mining timbers, marine piling. It is the main Australian species for marine piling, because its high silica content makes it resistant to Teredinidae marine borers.

Construction. As seasoned sawn timber in general house framing, internal and external flooring, lining, cladding.

Decorative. Plywood, laminated beams and bench tops, joinery, parquetry flooring.

Others. Boat building (knees, gunwales, planking, decking). Has been used for oyster stakes, wine casks, mallets, and bearings.

Identification features

General characteristics

Sapwood. Cream, distinct from heartwood.

Heartwood. Deep red to red-brown.

Texture. Fine to medium, uniform; grain often interlocked.

Wood structure

Vessels. Small, solitary, numerous and uniformly distributed. An occasional narrow zone free from vessels may be present. Tyloses common.

Vessel lines. Fine, but distinct.

Parenchyma. Indistinct under a lens.

Rays. Fine but visible with a lens.

Other features

Burning splinter test. A match size splinter burns to charcoal. This test separates it from brush box which is very similar both anatomically and in general appearance but which burns with a sooty flame to a white ash.

Further reading

Boland, DJ, Brooker, MIH, Chippendale, GM, Hall, N, Hyland, BPM, Johnston, RD, Kleinig, DA and Turner, JD 2006, 'Forest trees of Australia', 5th edn, CSIRO Publishing, Collingwood Australia.

Bootle, K 2005, 'Wood in Australia: types, properties and uses', 2nd edn, McGraw-Hill, Sydney.

Hopewell, G (ed.) 2006, 'Construction timbers in Queensland: properties and specifications for satisfactory performance of construction timbers in Queensland, Class 1 and Class 10 buildings', books 1 and 2, Department of Primary Industries and Fisheries, Brisbane.

Ilic, J 1991, 'CSIRO atlas of hardwoods', Crawford House Press, Bathurst, Australia.

Standards Australia, 2000, 'AS 2082-2000: Timber - hardwood - visually stress-graded for structural purposes', Standards Australia.

Last updated 17 August 2010