IDENTIFYING WOOD
Whether you are restoring a piece of furniture made from an unfamiliar wood or debating the authenticity of a particular board with a local lumberyard, a knack for identifying a piece of lumber is a useful skill.
Of course, an entire branch of knowledge is devoted to wood science and technology. Books have been written about the subject, careers have been founded upon it, and universities offer courses and degrees devoted to it. Scientists identify wood by first slicing off a thin sliver of a sample, then mounting it on a slide and examining it under a microscope.
The practicing woodworker, however, who is more interested in sawing than in science, can successfully identify most woods by methodically searching for a few simple clues with the help of inexpensive equipment. Most of the tools you need are illustrated at right. Your investigation should begin with the easily observable properties of the sample (page 26). Examine and feel the surface; determine whether it is oily or dry, dull or lustrous. Check its hardness by trying to dent the surface with a fingernail. You
may be able to tell with the naked eye whether a hardwood is ring - or diffuse- porous. As shown in the photos on page 33, these two types of hardwood are relatively easy to tell apart when viewed with a hand lens. Note whether the texture of the wood is coarse or smooth. If the sample has been recently cut, it may have a recognizable odor. If it has been sufficiently dried, you may be able to calculate its specific gravity.
Although these observations can help narrow down the choices, you will still have to view a wood sample under magnification in order to hazard an educated guess as to its species. The illustration on page 31 shows the three ways that a sample can be studied: transversely, radi
TOOLS FOR THE WOOD SLEUTH
ally or tangentially. Each method exposes a different view of a sample’s anatomical structure. The simplest view is the transverse since it involves looking at the end grain of the sample. However, to avoid a blurred view of crushed fibers, you must first shave the surface with a razor blade or a well-sharpened knife. To get a tangential view of a sample, you will need to make a clean cut along the growth rings of the wood (page 32). Making a second cut at right angles to the first exposes a radial view.
Once you have observed and recorded the sample’s properties and microscopic details, you can compare the results with a printed key of wood species to identify the wood.
