Surface roughness and color characteristics of wood treated with preservatives after accelerated weathering test Ali Temiz a, * , Umit C. Yildiz a , Ismail Aydin a , Morten Eikenes b , Gry Alfredsen b , Gu ¨rsel C ¸ olakoglu a a Karadeniz Technical University, Faculty of Forestry, Forest Industry Engineering Department, 61080 Trabzon, Turkey b Norwegian Forest Research Institute, Høgskoleveien 12, N-1432 A ˚ s, Norway Received 5 November 2004; received in revised form 10 December 2004; accepted 10 December 2004 Available online 13 January 2005 Abstract Wood samples treated with ammonium copper quat (ACQ 1900 and ACQ 2200), chromated copper arsenate (CCA), Tanalith E 3491 and Wolmanit CX-8 have been studied in accelerated weathering experiments. The weathering experiment was performed by cycles of 2 h UV-light irradiation followed by water spray for 18 min. The changes on the surface of the weathered samples were characterized by roughness and color measurements on the samples with 0, 200, 400 and 600 h of total weathering. The objective of this study was to investigate the changes created by weathering on impregnated wood with several different wood preservatives. This study was performed on the accelerated weathering test cycle, using UV irradiation and water spray in order to simulate natural weathering. Surface roughness and color measurement was used to investigate the changes after several intervals (0–200–400–600 h) in artificial weathering of treated and untreated wood. # 2004 Elsevier B.V. All rights reserved. Keywords: Photodegradation; Surface roughness; Color changes; Pine; Alder; Copper-containing wood preservatives 1. Introduction Wood is a good light absorber due to the presence of several chromophores, e.g. phenolic hydroxyl groups, aromatic skeleton, double bonds and carbonyl groups [1–3]. When wood is exposed to outdoor climate, a complex combination of chemical, mechan- ical and energy factors contribute to what is described as a weathering [3]. The exposure to ultraviolet (UV) irradiation and water are the main factors of wood weathering [1,4–6]. Photochemical degradation is manifested by an initial color change, followed by loss of gloss, roughening and checking. The change of wood color is thought to be due mainly to the UV light www.elsevier.com/locate/apsusc Applied Surface Science 250 (2005) 35–42 * Corresponding author. Tel.: +90 462 377 28 51; fax: +90 462 325 74 99. E-mail address: temiz@ktu.edu.tr (A. Temiz). 0169-4332/$ – see front matter # 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.apsusc.2004.12.019