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Blush walnut

Scientific name

Beilschmiedia obtusifolia. Family: Lauraceae

Other names

hard bollygum; tormenta

Description

  • Large hardwood tree.
  • Grows to 50m high.
  • Stem diameter of 1.0m.
  • Trunk is sometimes flanged at the base.
  • Bark is grey or brown, and scaly or marked by scattered indents.

Occurrence

  • Occurs in coastal scrubs from the Clarence River area of New South Wales to the Cairns district.

Appearance

Colour

  • Heartwood is yellowish-brown to blush pink.
  • Sapwood is paler.

Grain

  • Usually straight with fine grain.

Uses

Decorative

  • Panelling.
  • Turnery.
  • Office fittings.
  • Scotia and cornice moulds.
  • Architraves.
  • Plywood.

Others

  • Internal flooring.
  • Framing.
  • Shelving.
  • Roof battens.
  • Fishing rod butts.
  • Chisel handles.
  • Cases.
  • Crates.
  • Staves for tallow casks.

Properties

  • Density: 770kg/m3 at 12% moisture content; about 1.3m3 of seasoned sawn timber per tonne.
  • Strength groups: S4 unseasoned, SD5 seasoned.
  • Stress grades: F7, F8, F11, F14 (unseasoned); F8, F11, F14, F17 (seasoned), when visually stress-graded according to AS 2082—2000: Timber—Hardwood—Visually stress-graded for structural purposes.
  • Joint groups: JD2 seasoned.
  • Shrinkage to 12% MC: 6.1% (tangential), 2.7% (radial).
  • Unit shrinkage: 0.36% (tangential), 0.19% (radial)—these values apply to timber reconditioned after seasoning.
  • Durability above-ground: Class 4 (life expectancy 0—7 years).
  • Durability in-ground: Class 4 (life expectancy 0—5 years).
  • Lyctine susceptibility: untreated sapwood susceptible to lyctid borer attack.
  • Termite resistance: not resistant.
  • Preservation: sapwood readily impregnates with preservative.
  • Seasoning: dry carefully to limit checking; air dry under cover before kiln seasoning; collapse is slight.
  • Hardness: moderately hard (rated 3 on a 6-class scale) to indent work with hand tools.
  • Machining: hard to work because it’s abrasive on cutting edges.
  • Fixing: no difficulty using standard fittings and fastenings.
  • Gluing: bonds are satisfactory using standard procedures.
  • Finishing: readily accepts stain, polish and paint.

Identification features

General characteristics

  • Sapwood: pale pink-brown.
  • Heartwood: yellow-brown to pink-brown.
  • Texture: medium to fine, grain straight.

Wood structure

  • Growth rings: absent.
  • Vessels: small, visible without lens; some solitary but most as short radial multiples; vessel lines distinct on longitudinal surfaces.
  • Parenchyma (soft tissue): Abundant in irregularly spaced apotracheal bands, distinct without lens, also vasicentric tracheids are visible under lens.
  • Rays: distinct without a lens.

Other features

  • Burning splinter test: match-size splinter burns to a full white ash.
  • Oil cells: detect in cross-section with the aid of a 10× lens.

Research and resources

  • Boland, DJ, Brooker, MIH, Chippendale, GM, Hall, N, Hyland, BPM, Johnston, RD, Kleinig, DA and Turner, JD 2006, Forest trees of Australia, 5th ed., CSIRO Publishing, Collingwood, Australia.
  • Bootle, K 2005, Wood in Australia: Types, properties and uses, 2nd ed., McGraw-Hill, Sydney.
  • Ilic, J 1991, CSIRO atlas of hardwoods, Crawford House Press, Bathurst, Australia.
  • Queensland Government, DAF 2018, Construction timbers in Queensland: properties and specifications for satisfactory performance of construction timbers in Queensland. Class 1 and Class 10 buildings, Books 1 & 2, Department of Agriculture and Fisheries, Brisbane.
  • Standards Australia, 2000, AS 2082—2000: Timber—Hardwood—Visually stress-graded for structural purposes, Standards Australia International, Strathfield, NSW.