Weathering of wood

The appearance of wood exposed outdoors without protective paint, stain, or treatment changes markedly in a few months then the wood remains almost unaltered for years (9-11). Color of the wood is affected very early (11,12). Generally, all unprotected woods change in color to a brown. After prolonged weathering, all woods become gray (9). Recent research has been concerned with many aspects of weathering of wood (13-18). 

Forest Products Laboratory, "Wood Finishing Weathering of Wood," 4 pp., USDA For. Serv. Res. Note FPL-0135, For. Prod. Lab., Madison, Wis., 1975. 

The weathering of wood is caused primarily by the action of ultraviolet (UV) light, water, heat, and abrasion. The contribution of these elements to the wood weathering process has... 

Feist, W. C. Weathering of wood in structural uses, "Proc. Symp. Structural use of wood in adverse environments." [Vancouver, B.C., 1978] Soc. Wood Sci. Tech., Madison, Wis. 1982 (In Press)... 

The weathering of wood surfaces under natural or artificial conditions has been widely studied in recent years and the application of modem instrumental... 

Marah is an area of desert located near the Red Sea on the Sinai Peninsula. The desert water is bitter due to high alkalinity. Weathering of wood on the desert by the sun causes the alcohol groups of cellulose and hemicellulose to be oxidized to carboxyl groups. By throwing a piece of weathered wood into the alkaline water, an acid-base reaction takes place in which the alkalinity of the water is reduced. Thereby, the water becomes sweet. 

Although the weathering of wood materials depends on many environmental factors, there is mounting evidence that only a relatively narrow band of the electromagnetic spectrum, i.e., the UV-light portion of sunlight, is responsible for the primary photooxidative degradation of wood. 

The weathering process described thus far has been for solid wood. The introduction of another variable, the adhesive, in the weathering of wood-based materials such as plywood and particle board creates additional complications. Wood substance is still ex-... 

ACCELERATED AND NATURAL WEATHERING OF WOOD-PLASTIC COMPOSITE MATERIALS AND A CORRELATION (OR LACK OF IT) BETWEEN THEM THE ACCELERATION FACTOR... 

Fabiyi, A. McDonald, M. Wolcott, and K. England. Chemical changes that occur during the weathering of wood plastic composites. In 8th International Conference on Woodfiber Composites, Forest Products Society, Madison, WI, May 23-25, 2005. 

N.M. Stark. Factors influencing the weatherability of wood-polyethylene composites. In Proceedings of The Global Outlook for Natural Fiber Wood Composites 2003, Intertech, Portland, ME, New Orleans, LA, December 3-5, 2003. 

Biologically Induced Changes. All modern studies on the weathering of wood conclude that the final discoloration (graying) of wood in the presence of moisture is practically always due to growth of fungi on the wood surface (i, 2, 54, 65-69). The most frequently observed species is Aureobasidium... 

R. S. Williams, Weathering of Wood, in Handbook of Wood Chemistry and Wood Composites, R.M. Rowell, (Ed.), pp. 139-185, CRC Press, Boca Raton (2005). 

S. Butylina, M. Hyvarinen and T. Karki, Accelerated weathering of wood-polypropylene composites containing minerals. Compos. A, 43, 2087-2094 (2012). 

Evans, P.D. Weathering of wood and wood composites. In Rowell, R.M. (ed.) Handbook of wood chemistry and wood composites, p. 151. CRC Press, New York (2012)... 

Hansmann, C., Deka, M., Wimmer, R., Gindl, W. Artificial weathering of wood surfaces modified by melamine formaldehyde resins. Holz als Roh Werkst. 64, 198-203 (2006)... 

Butylina, S., Hyvarinen, M., Karki, T. Weathering of wood-polypropylene composites containing pigments. Eur. J. Wood Wood Prod. 70, 719-726 (2012)... 

Grull, G., Forsthuber, B., Tscheme, F., Spitaler, I. Weathering indicator for artificial and natural weathering of wood coatings. Eur. J. Wood Wood Prod. 72, 681-684 (2014)... 

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