Journal of Coatings Technology and Research

, Volume 16, Issue 2, pp 339–352 | Cite as

Critical view on the possibility of color changes prediction in the surfaces of painted wood exposed outdoors using accelerated weathering in Xenotest

  • Miloš PánekEmail author
  • Ladislav Reinprecht


The capability to correlate exactly the process of outdoor natural weathering for the coating systems on wood surfaces via their artificial weathering in laboratory conditions would significantly reduce the testing times. In this work, a weathering of 16 different coating systems applied on two wood species (Norway spruce and black locust) having two different degrees of roughness (smooth, rough) was performed with the aim to compare direction and intensity of their color changes in natural exterior exposure without ground contact lasting from 6 to 36 months and in Xenotest lasting from 1 to 12 weeks, respectively. Correlation relationships between the natural and accelerated weathering of painted woods have been evaluated based on linear regressions for changing of the CIE-L*a*b* color parameters ΔL* and ΔE* and by non-linear Spearman rank correlation of ΔE* values. The results exhibit better possibilities for correlating the color changes for wood painted with pigmented coatings compared to transparent ones. The precision of the employed correlations has also been affected by the underlying wood species and its roughness before application of the coating. This means that, in the modeling of painted wood weathering, it is necessary to take into account a number of other factors in addition to the specific climatic conditions of exposure.


Coatings Wood Color Exterior weathering Artificial weathering Correlation 



The authors are very grateful for the financial support of the University Internal Grant Agency of the Czech University of Life Sciences, Prague, Project CIGA No. 20174304, and of the Slovak Research and Development Agency in Bratislava under the Contract Nos. APVV-0200-12 and VEGA 1/0729/18.


  1. 1.
    Ghosch, SC, Militz, H, Mai, C, “Natural Weathering of Scots Pine (Pinus sylvestris L.) Boards Modified with Functionalised Commercial Silicone Emulsions.” BioResources, 4 (2) 659–673 (2009). Google Scholar
  2. 2.
    Gobakken, LR, Lebow, PK, “Modelling Mould Growth on Coated Modified and Unmodified Wood Substrates Exposed Outdoors.” Wood Sci Technol, 44 (2) 315–333 (2010). CrossRefGoogle Scholar
  3. 3.
    De Windt, I, Van den Bulcke, J, Wuijtens, I, Coppens, H, Van Acker, J, “Outdoor Weathering Performance Parameters of Exterior Wood Coating Systems on Tropical Hardwood Substrates.” Eur. J. Wood Wood Prod., 72 (2) 261–272 (2014). CrossRefGoogle Scholar
  4. 4.
    ASTM D6763, Standard guide for testing exterior wood stains and clear water repellents, p. 9. ASTM International, West Conshohocken (2016). Google Scholar
  5. 5.
    EN 927-3, Paints and varnishes. Coating materials and coating system for exterior wood—Part 3: natural weathering test. European Committee for Standardization, Brussels (2006)Google Scholar
  6. 6.
    Grüll, G, Tscherne, F, Spitaler, I, Forsthuber, B, “Comparison of Wood Coating Durability in Natural Weathering and Artificial Weathering Using Florescent UV-Lamps and Water.” Eur. J. Wood Wood Prod., 72 (3) 367–376 (2014). CrossRefGoogle Scholar
  7. 7.
    Evans, PD, Haase, JG, Shakri, A, Seman, BM, Kiguchi, M, “The Search for Durable Exterior Clear Coatings for Wood.” Coatings, 5 830–864 (2015). CrossRefGoogle Scholar
  8. 8.
    Van den Bulcke, J, Van Acker, J, Stevens, M, “Experimental and Theoretical Behavior of Exterior Wood Coatings Subjected to Artificial Weathering.” J. Coat. Technol. Res., 5 (2) 221–231 (2008). CrossRefGoogle Scholar
  9. 9.
    Ozgenc, O, Okan, OT, Yildiz, UC, Deniz, I, “Wood Surface Protection Against Artificial Weathering with Vegetable Seed Oils.” BioResources, 8 (4) 6242–6262 (2013). CrossRefGoogle Scholar
  10. 10.
    ASTM G151, Standard practice for exposing nonmetallic materials in accelerated test devices that use laboratory light sources, p. 15. ASTM International, West Conshohocken (2010). Google Scholar
  11. 11.
    EN 927-6, Paints and varnishes: coating materials and coating systems for exterior wood—Part 6: exposure of wood coatings to artificial weathering using fluorescent UV lamps and water. European Committee for Standardization, Brussels (2006)Google Scholar
  12. 12.
    Adamopoulos, S, Xie, Y, Militz, H, “Distribution of Blue Stain in Untreated and DMDHEU Treated Scots Pine Sapwood Panels After Six Years of Outdoor Weathering.” Eur. J. Wood Wood Prod., 69 (2) 333–336 (2011). CrossRefGoogle Scholar
  13. 13.
    Grüll, G, Truskaller, M, Podgorski, L, Bollmus, S, Tscherne, F, “Maintenance Procedures and Definition of Limit States for Exterior Wood Coatings.” Eur. J. Wood Wood Prod., 69 (3) 443–450 (2011). CrossRefGoogle Scholar
  14. 14.
    Smeland, KA, Liland, KH, Sandak, J, Sandak, A, Gobakken, LR, Thiis, TK, Burud, I, “Near Infrared Hyperspectral Imaging in Transmission Mode: Assessing the Weathering of Thin Wood Sample.” J. Near Infrared Spectrosc., 24 595–604 (2016). CrossRefGoogle Scholar
  15. 15.
    Forsthuber, B, Schaller, C, Grüll, G, “Evaluation of the Photostabilizing Efficiency of Clear Coatings Comprising Organic UV Absorbers and Mineral UV Screeners on Wood Surfaces.” Wood Sci. Technol., 47 (2) 281–297 (2013). CrossRefGoogle Scholar
  16. 16.
    Turkoglu, T, Baysal, E, Toker, H, “The Effects of Natural Weathering on Color Stability of Impregnated and Varnished Wood Materials.” Adv. Mater. Sci. Eng., 60 (5) 9 (2015). Google Scholar
  17. 17.
    Pánek, M, Reinprecht, L, “Effect of Vegetable Oils on the Colour Stability of Four Tropical Woods During Natural and Artificial Weathering.” J. Wood Sci., 62 (1) 74–84 (2016). CrossRefGoogle Scholar
  18. 18.
    Ghosh, M, Gupta, S, Kumar, VSK, “Studies on the Loss of Gloss of Shellac and Polyurethane Finishes Exposed to UV.” Maderas-Cienc. y Tecnol., 17 (1) 39–44 (2015). Google Scholar
  19. 19.
    Mamoňová, M, Reinprecht, L “Štruktúra a farba akrylátových náterov po ročnej expozícii v exteriéri a interiéri. (Structure and color of acrylate coatings after inner and outer one-year-long exposition).” In: Interaction of Wood with Various Forms of Energy, Technical University in Zvolen, Slovakia, pp. 91-97 (2008).Google Scholar
  20. 20.
    Grüll, G, Forsthuber, B, Tscherne, F, Spitaler, I, “Weathering Indicator for Artificial and Natural Weathering of Wood Coatings.” Eur. J. Wood Wood Prod., 72 (5) 681–684 (2014). CrossRefGoogle Scholar
  21. 21.
    Gaylarde, CC, Morton, LHG, Loh, K, Shirakawa, MA, “Biodeterioration of Extrenal Architectural Paint Films: A Review.” Int. Biodeterior. Biodegrad., 65 1189–1198 (2011). CrossRefGoogle Scholar
  22. 22.
    Yalinkiliç, MK, Ilhan, R, Imamura, Y, Takahashi, M, Demirci, Z, Yalinkilic, AC, Peker, H, “Weathering Durability of CCB-Impregnated Wood for Clear Varnish Coatings.” J. Wood Sci., 45 (6) 502–514 (1999). CrossRefGoogle Scholar
  23. 23.
    Ozdemir, T, Hiziroglu, S, Kocapinar, M, “Adhesion Strength of Cellulosic Varnish Coated Wood Species as Function of Their Surface Roughness.” J. Wood Sci., (2015). Google Scholar
  24. 24.
    Wȧlinder, M, Brelid, PL, Segerholm, K, Long, ICJ, Dickerson, JP, "Wettability of Acetylated Southern Yellow Pine." Int. Wood Prod. J., 4 (3) 197–203 (2013)CrossRefGoogle Scholar
  25. 25.
    CIE, Colorimetry. 2nd edition, CIE Pub. No. 15.2. Commission Internationale de l’Eclairage, Vienna, 74 p. (1986)Google Scholar
  26. 26.
    Kiguchi, M, Evans, PD, “Photostabilisation of Wood Surfaces Using a Grafted Benzophenone UV Absorber.” Polym. Degrad. Stab., 61 33–45 (1998)CrossRefGoogle Scholar
  27. 27.
    Q-LAB, “Correlation of laboratory to natural weathering.” Technical Bulletin LU-0824. 12 p. (1977).
  28. 28.
    Carlozzo, BJ, Andrews, J, Anwari, F, DiLorenzo, M, Glover, R, Grossman, S, Harding, C, McCarthy, J, Mysza, B, Raymond, R, Skerry, B, Slifko, PM, Stipkovich, W, Weaver, JC, Wilson, G, “Correlation of Accelerated Exposure Testing and Exterior Exposure Sites. 2. One-Year Results.” J. Coat. Technol., 68 (858) 47–61 (1996)Google Scholar
  29. 29.
    Valverde, JC, Moya, R, “Correlation and Modeling Between Color Variation and Quality of the Surface Between Accelerated and Natural Tropical Weathering in Acacia mangium, Cedrela odorata and Tectona grandis Wood with Two Coatings.” Color Res. Appl., 39 (5) 519–529 (2014). CrossRefGoogle Scholar
  30. 30.
    Reinprecht, L, Pánek, M, “Effects of Wood Roughness, Light Pigments, and Water Repellent on the Color Stability of Painted Spruce Subjected to Natural and Accelerated Weathering.” BioResources, 10 (4) 7203–7219 (2015). CrossRefGoogle Scholar
  31. 31.
    Moya, R, Rodríguez-Zúñiga, A, Vega-Baudrit, J, Puente-Urbina, A, “Effects of Adding TiO2 Nanoparticles to a Water-Based Varnish for Wood Applied to Nine Tropical Woods of Costa Rica Exposed to Natural and Accelerated Weathering.” J. Coat. Technol. Res., 14 (1) 141–152 (2016). CrossRefGoogle Scholar
  32. 32.
    Creemers, J, De Meijer, M, Zimmermann, T, Sell, J, “Influence of Climatic Factors on the Weathering of Coated Wood.” Holz Roh Werkst, 60 (6) 411–420 (2002). CrossRefGoogle Scholar
  33. 33.
    Mattos, BD, De Cademartori, PHG, Lourençon, TV, Gatto, DA, “Colour Changes of Brazilian Eucalypts Wood by Natural Weathering.” Int. Wood Prod. J., 5 (1) 33–38 (2014)CrossRefGoogle Scholar
  34. 34.
    Schnabel, T, Zimmer, B, Petutschnigg, AJ, “On the Modelling of Colour Changes of Wood Surfaces.” Eur. J. Wood Wood Prod., 67 141–149 (2009). CrossRefGoogle Scholar
  35. 35.
    EN ISO 4287, Geometrical product specifications (GPS): surface texture. Profile method. Terms, definitions and surface texture parameters. International Organization for Standardization, Geneva (1997)Google Scholar
  36. 36.
    EN ISO 4288, Geometrical product specifications (GPS): surface texture. Profile method. Rules and procedures for the assessment of surface texture. International Organization for Standardization, Geneva (1996)Google Scholar
  37. 37.
    Leštianska A, Vido J, Střelcová K, Evaluation of Extremity Climatic Characteristics in the Zvolenská Valley and its Surrounding in Different Forest Vegetation Levels during the Vegetation Seasons 2009–2013. In: Transport of water, chemicals and energy in the soil-plant-atmosphere systém, vol 21. International Poster Day and Institute of Hydrology Open Day, Institute of Hydrology SAS, Bratislava, Slovakia, pp 159–170 (2014)Google Scholar
  38. 38.
    Evans PD, “Weathering and Photo-degradation of Wood.” In: Development of Wood Preservative Systems, ACS, Washington, pp 69–117 (2008)Google Scholar
  39. 39.
    Sudiyani, Y, “Chemical Characteristics of Surfaces of Hardwood and Softwood Deteriorated by Weathering.” J. Wood Sci., 45 (4) 348–353 (1999). CrossRefGoogle Scholar
  40. 40.
    Pandey, KK, “A Note on the Influence of Extractives on the Photo-Discoloration and Photo-Degradation of Wood.” Polym. Degrad. Stab., 87 375–379 (2005). CrossRefGoogle Scholar
  41. 41.
    Ozdemir, T, Hiziroglu, S, “Influence of Surface Roughness and Species on Bond Strength Between the Wood and the Finish.” For. Prod. J., 59 (6) 90–94 (2009)Google Scholar
  42. 42.
    Vitosyto, J, Ukvalbergieno, K, Keturakis, G, “The Effects of Surface Roughness on Adhesion Strength of Coated Ash (Fraxinus excelsior L.) and Birch (Betula L.) Wood.” Medziagotyra, 18 (4) 347–351 (2012)Google Scholar
  43. 43.
    Slabejová, G, Fekiač, J, Pánek, M, “Vplyv vybraných faktorov na zmenu farby transparentných povrchových úprav bukového dreva. (Influence of Selected Factors on a Colour Change of the Transparent Finishes of Beech Wood).” Acta Facultatis Xylologiae Zvolen, 56 (1) 23–30 (2014)Google Scholar
  44. 44.
    Van den Bulcke, J, Rijckaert, V, Van Acker, J, Stevens, M, “Adhesion and Weathering Performance of Waterborne Coatings Applied to Different Temperate and Tropical Wood Species.” J. Coat. Technol. Res., 3 (3) 185–191 (2006)Google Scholar
  45. 45.
    Evans, PD, Chowdhury, MJ, “Photostabilization of wood with higher molecular weight UV absorbers.” In: 41th Annual Meeting IRG/WP, Biarritz, France, IRG/WP-10-30524 (2010)Google Scholar
  46. 46.
    Reinprecht, L, Pánek, M, “Vplyv pigmentov v náteroch na prirodzené a urýchlené starnutie povrchov smrekového dreva (Effect of Pigments in Paints on the Natural and Accelerated Ageing of Spruce Wood Surfaces).” Acta Facultatis Xylologiae Zvolen, 55 (1) 71–84 (2013)Google Scholar
  47. 47.
    Müller, U, Rätzsch, M, Schwanninger, M, Steiner, M, Zöbl, H, “Yellowing and IR-Changes of Spruce Wood as a Result of UV Irradiation.” J. Photochem. Photobiol. B, 69 97–105 (2003). CrossRefGoogle Scholar
  48. 48.
    Baar, J, Gryc, V, “The Analysis of Tropical Wood Discoloration Caused by Simulated Sunlight.” Eur. J. Wood Wood Prod., 70 (1–3) 263–269 (2012). CrossRefGoogle Scholar
  49. 49.
    De Meier, M, “Review on the Durability of Exterior Wood Coatings with Reduced VOC-Content.” Prog. Org. Coat., 43 (4) 217–225 (2001). CrossRefGoogle Scholar
  50. 50.
    Syvrikaya, H, Hafizoglu, H, Yasav, A, Aydemir, D, “Natural Weathering of Oak (Quercus petraea) and Chestnut (Castanea sativa) Coated with Various Finishes.” Color Res. Appl., 36 (1) 72–78 (2011). CrossRefGoogle Scholar
  51. 51.
    Crewdson, MJ, Ketola, WD, “Best Practices in Weathering: Outdoor and Accelerated Testing Compared.” Eur. Coat. J., 4 116–121 (2009), (ISSN: 09303847)Google Scholar

Copyright information

© American Coatings Association 2018

Authors and Affiliations

  1. 1.Faculty of Forestry and Wood SciencesCzech University of Life Sciences PraguePrague 6 – SuchdolCzech Republic
  2. 2.Faculty of Wood Sciences and TechnologyTechnical University in ZvolenZvolenSlovak Republic

Personalised recommendations