Tuesday, December 22, 2009

The Properties Of Eucalyptus Wood

Eucalyptus lumber varies by species.


Members of the Eucalyptus genus, native to Australia and other parts of Oceania, are notable for the essential oils produced from their leaves. These trees are also used to produce a variety of different types of timber. Several different species are sold on the North American market, often labeled simply as "eucalyptus." These woods have some similarities, but can vary significantly in appearance and characteristics.


Eucalyptus Resinifera


Also called red mahogany eucalyptus, eucalypt, Australian red mahogany and kino eucalyptus, this tree is common in flooring, plywood and furniture construction. It may also be used for decorative veneers. Eucalyptus resinifera is extremely dense, with a rippling grain and a hardness of 2710 on the Janka scale, an industry standard comparison scale rating the hardness and duribility of wood. This tree produces pale cream sapwood and striking dark red heartwood with some resistance to termites. The wood is resinous and hard but easy to work, sand and polish.








Eucalyptus Diversicolor


Also known as karri wood, this tree is indigenous to western Australia, but has spread throughout Oceania and southeast Asia. It is often used for building construction, rafter, timbers, flooring and other applications that require very durable wood. Eucalyptus diversicolor has a hardness of 2030 on the Janka scale and produces reddish-brown heartwood with slightly paler sapwood. It has an interlocked grain that produces a striped appearance when quartersawn. This wood has poor dimensional stability and resists treatment with preservatives. It blunts cutting tools readily and is hard to saw and machine, but does glue and polish well.


Eucalyptus Obliqua


This eucalyptus is also called figured eucalyptus and brown-top stringbark. It can be used for a wide range of purposes, ranging from simple construction to fine furniture. Eucalyptus obliqua has a lower hardness rating than other species in its genus, rating only 1630 on the Janka scale, but is still harder than most North American hardwoods. This tree produces light brown to pale brown wood, sometimes with a pink tinge. The heartwood and sapwood are hard to distinguish. Even seasoned wood shows some movement over time, and the sapwood is vulnerable to beetle attack. Eucalyptus obliqua wood often suffers from gum veins and is relatively easy to work, though it tends to blunt tools.


Eucalyptus Citriodora


Also called lemon eucalyptus and lemon-scented gum, this species has historically been used for medicinal purposes, brushes, cabinetry and construction. It grows in Australia and Polynesia. Lemon eucalyptus scores 1798 on the Janka scale, and produces wide white to cream sapwood and light to dark brown heartwood with a straight or fiddleback grain. It does not resist termites or borers, but does perform well outdoors. Lemon eucalyptus often has greasy surfaces and may cause skin irritation in sensitive people. It saws, carves and works easily, but is hard to nail.

Tags: Janka scale, heartwood with, also used, cream sapwood, easy work, Janka scale produces, Lemon eucalyptus