Douglas fir
Description
A tall, evergreen tree, Pseudotsuga menziesii (also called P. douglasii and P. taxifolia) found at high elevations in the western part of North America. The Douglas fir has been called the greatest of all trees as it is the most used timber in the world. The oldest species of Douglas fir is estimated at 1300 years old. The coniferous tree averages over 100 feet in height and 10 feet in thickness. Record setting heights of 417 feet and girths 49 feet have been measured. Douglas firs produce a reddish-brown softwood that is durable and resistant to insects. It has a straight grain with a slightly uneven texture. A turpentine-like resin exudes from the freshly cut wood. Timber from the Douglas fir is used in home construction, telephone poles, bridges, millwork, fences, barrels, plywood, chipboard, and kraft paper pulp. The wood is moderately acidic containing some organic acids. The bark contains catechol type tannins that are used to produce pliable, light-color leathers. The bark also contains a hard glossy wax similar to carnauba wax.
Synonyms and Related Terms
Pseudotsuga menziesii; Pseudotsuga douglasii; Pseudotsuga taxifolia; pin Douglas (Fr.); pin d'Oregon (Fr.); Douglastanne (Deut.); pino d'Oregon (It., Esp.); abeto de Douglas (Esp.); pseudotsuga (Port.); duglasia (It.); Douglas pine; Douglas spruce; Oregon fir; Oregon pine; red fir; red pine; Puget Sound pine; yellow fir
Other Properties
Color: Red-brown summerwood and softer, yellowish springwood. Rings:distinct. Pores:absent. Grain: distinct. Rays:obscure. Soft, lightweight, resin canals visible.
| Density | 31-42 ppcf |
|---|---|
| Molecular Weight | specific gravity = 0.50 |
Paper fiber type: Using transmitted light microscopy, fibers are identified by the presence of spiral thickening and piceoid pits 2-4 across. Since this is an abrupt transition softwood, there is a marked difference between early and late wood fibers. Appearance with Graff "C" stain: . Average dimensions of fibers: length 3.9mm, width 35-45μm. Common pulping method: kraft and sulfite.
Hazards and Safety
Splinter wounds heal slowly and often become infected.
Additional Information
Schoch, W., Heller, I., Schweingruber, F.H., Kienast, F., 2004:Wood anatomy of central European Species: Douglas Fir,Oregon Pine, Pseudotsuga menziesii (Mirb.) Franco
Additional Images
Douglas fir paper pulp stained with Graff "C" stain
Douglas fir paper pulp stained with Graff "C" stain
Authority
- G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 274
- H.L.Edlin, What Wood is That?, Viking Press, New York, 1969
- Encyclopedia Britannica, http://www.britannica.com Comment: Douglas fir. Retrieved May 29, 2003, from Encyclopædia Britannica Premium Service.
- Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996
- F. H. Titmuss, Commercial Timbers of the World, The Technical Press Ltd., London, 1965
- Matte Paint: Its history and technology, analysis, properties and conservation treatment, Eric Hansen, Sue Walston, Mitchell Bishop (ed.), J. Paul Getty Trust, Los Angeles, Vol. 30 of AATA, 1993
- Michael McCann, Artist Beware, Watson-Guptill Publications, New York City, 1979
- External source or communication Comment: Western Pine Association, Portland, Oregon: air-dry weight = 34 pcf
- Marja-Sisko Ilvessalo-Pfäffli. Fiber Atlas: Identification of Papermaking Fibers (Springer Series in Wood Science). Springer, 1995.
- Walter Rantanen. "Fiber ID Course." Integrated Paper Services. June 2013. Lecture.