Effectiveness of european oak wood staining with iron (ii) sulphate during natural weathering

Agnieszka  Jankowska; Arkadiusz  Kwiatkowski

doi:10.4067/s0718-221x2022000100415

Authors

Agnieszka Jankowska
Arkadiusz Kwiatkowski

DOI:

https://doi.org/10.4067/s0718-221x2022000100415

Keywords:

Artificial graying, colour changes, European oak, iron sulphate, weathering

Abstract

Artificial graying of wood can be solution for contemporary trends of using uncoated wood for the arrangement of external architecture. The presented work was aimed at investigation of colour changes of European oak (Quercus sp.) wood surface treated with iron (II) sulphate. Three different procedures differing in time (2 h and 24 h) and temperature (20 °C and 70 °C) were used, as well as three different concentrations of aqueous iron (II) sulphate solutions (10 %, 20 %, 30 %). Beside the colour itself, it was evaluated the stained oak wood discolouration due to natural weathering. Thanks to iron (II) sulphate, wood colour changed to dark grey. In general, the colour changes on tangential section of wood were higher than those on radial section what was result of wood structure, in particular parenchyma cells arrangement in wooden rays. Contrary to expectations, the concentration of the iron (II) sulphate solution was not of significant importance for wood staining. Usage of concentrations higher than 10 % for the modification of the colour of wood gives the same effects. However, with increasing solution used to wood staining, the colour stability of the wood decreases during external exposure. The parameters of the procedure were not significantly affected. This allows the application of the simplest and least time-consuming modification method to be considered.

Downloads

Download data is not yet available.

References

Canevari, C.; Delorenzi, M.; Invernizzi, C.; Licchelli, M.; Malagodi, M.; Rovetta, T. 2016. Chemical characterization of wood samples colored with iron inks: insights into the ancient techniques of wood coloring. Wood Sci Technol 50: 1057–1070. https://doi.org/10.1007/s00226-016-0832-2

Data of Institute of Meteorology and Water Management. 2018. National Research Institute in Poland. https://danepubliczne.imgw.pl/

European Committee for Standardization. 2013. EN 335: Durability of wood and wood-based products. Use classes: definitions, application to solid wood and wood-based products. CEN. Brussels, Belgium.

European Committee for Standardization. 2016. EN 350: Durability of wood and wood-based products – Testing and classification of the durability to biological agents of wood and wood-based materials. CEN. Brussels, Belgium.

Evans, P.D. 2012. Weathering of wood and wood composites. In: Handbook of Wood Chemistry and Wood Composites. 2nd ed.; Rowel, R.M. (Ed.), CRC Press, Boca Raton, USA. https://doi.org/10.1201/b12487-10

Evans, P.D.; Haase, J.G.; Seman, A.S.; Kiguchi, M. 2015. The search for durable exterior clear coatings for wood. Coatings 5: 830–864. https://doi.org/10.3390/coatings5040830

Hillis, W.E. 1971. Distribution, properties and formation of some wood extractives. Wood Sci Technol 5(4): 272-289. https://doi.org/10.1007/BF00365060

Høibø, O.; Nyrud, A.Q. 2010. Consumer perception of wood surfaces: The relationship between stated preferences and visual homogeneity. J Wood Sci 56(4): 276–283. https://doi.org/10.1007/s10086-009-1104-7

Hon, D.N.S.; Minemura, N. 2001. Color and discoloration. In: Wood and cellulosic chemistry, 2nd edition. Hon D.N.S., Shiraishi N. (eds.) Marcel Dekker, New York, USA. https://doi.org/10.1021/ja015237p

Hundhausen, U.; Mai, C.; Slabohm, M.; Gschweidl, F.; Schwarzenbrunner, R. 2020. The Staining effect of iron (II) sulfate on nine different wooden substrates. Forests 11(6): 658. https://doi.org/10.3390/f11060658

Hunterlab. 1995. Use measurement of appearance. A Wiley-Interscience publication, Wiley and Sons, New York, USA.

International Organization for Standardization. 1984. ISO 7724-3: Paints and varnishes. Colorimetry. Part 3: Calculation of colour differences. ISO. Geneva, Switzerland.

Kreber, B. 1994. Understanding wood discoloration helps maximize wood profits. In Proceedings of Western Dry Kiln Association Meeting. Portland, Canada.

Krekel, Ch. 1999. Chemistry of Historical Iron Gall Inks. Int J Forensic Doc Examiners 5: 54-58.

Machová, D.; Baar, J.; Paschová, Z.; Pařil, P.; Křenková, J.; Kúdela, J. 2019. Color changes and accelerated ageing in oak wood treated with ammonia gas and iron nanoparticles. Eur J Wood Prod 77: 705–716. https://doi.org/10.1007/s00107-019-01406-x

Oberhofnerová, E.; Pánek, M.; García-Cimarras, A. 2017. The effect of natural weathering on untreated wood surface. Maderas-Cienc Tecnol 19(2): 173 – 184. http://dx.doi.org/10.4067/S0718-221X2017005000015

Richter, H.G.; Dallwitz, M.J. 2019. Commercial timbers: descriptions, illustrations, identification, and information retrieval. In English, French, German, Portuguese, and Spanish. http://delta-intkey.com

Srinivas, K.; Pandey, K.K. 2012. Photodegradation of thermally modified wood. Journal of Photochemistry and Photobiology B: Biology 117(5): 140 – 145. https://doi.org/10.1016/j.jphotobiol.2012.09.013

Swanna, A.L.S.; Longob, M.; Knox, R.G.; Leed, E.; Moorcroft, P.R. 2016. Future deforestation in the Amazon and consequences for South American climate. Agric For Meteorol 214–215: 12-24. https://doi.org/10.1016/j.agrformet.2015.07.006

TIBCO. 2013. Statistica v. 13.3 software.

Yamamoto, K.; Hong, L. 1989. Location of extractives and decay resistance in some Malaysian hardwood species. J Trop For Sci 2(1): 61-70.

Zimmer, K.; Gobakken, L.R.; Flindall, O.; Nygaard, M. 2018. Colour changes in unpainted wooden façades - Fifty Shades of Grey. In: Proceedings of the IRG/WP 49th IRG Annual Meeting. Johannesburg, Republic of South Africa.