Natural weathering of oak (Quercus petrae) and chestnut (Castanea sativa) coated with various finishes

Sivrikaya, Hüseyin; Hafızoğlu, Harzemşah; Yasav, Ali; Aydemir, Deniz

doi:10.1002/col.20581

Cited by 26 publications

(24 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This fact was emphasized even more through the use of oak as the underlying wood species. Due to its complicated morphological structure and large vessels [53], and the specific tannins content [67], the durability of exterior coatings applied to oak wood is relatively low [57]. Many commercial producers try to cope with this issue and do not recommend applying their coatings to oak wood, especially in transparent design; on the other hand, the high extractives content in oak protects its wood against bio-damage [54].…”

Section: Resultsmentioning

confidence: 99%

“…Since the degradation of the protective layer of hydrophobic coatings (A) and (B) occurred due to weathering, their significantly longer service life on an exterior with rain effects (Class 3 by EN 335 [1]) cannot be assumed-not even in the case of the application of other types of underlying wood. When exterior oil-based coating (C) is applied, a longer service life can be expected in the case of softwoods [79] that have a morphological structure that is more simple than hardwoods with wide open vessels [57]. However, each underlying wood can affect the service life of the coating individually through the specific content of the extractives [27], and it is therefore necessary to confirm these assumptions by testing and comparing the evaluated characteristics [20,23,25].…”

Section: Resultsmentioning

confidence: 99%

“…Nevertheless, it also quickly loses its original colour due to weathering [56], and proper surface treatment in the form of a coating system is thereby necessary in order to maintain its natural appearance. The application of coating systems is problematic due to the uneven structure and content of tannins [53], and therefore the service life of coatings is limited [57].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Efficacy of Hydrophobic Coatings in Protecting Oak Wood Surfaces during Accelerated Weathering

et al. 2017

View full text Add to dashboard Cite

Abstract:The durability of transparent coatings applied to an oak wood exterior is relatively low due to its anatomic structure and chemical composition. Enhancement of the protection of oak wood against weathering using transparent hydrophobic coatings is presented in this study. Oak wood surfaces were modified using UV-stabilizers, hindered amine light stabilizer (HALS), and ZnO and TiO 2 nanoparticles before the application of a commercial hydrophobic topcoat. A transparent oil-based coating was used as a control coating system. The artificial weathering test lasted 6 weeks and colour, gloss, and contact angle changes were regularly evaluated during this period. The changes in the microscopic structure were studied with confocal laser scanning microscopy. The results proved limited durability against weathering of both tested hydrophobic coatings. The formation of micro-cracks causing the leaching of degraded wood compounds and discolouration of oak wood were observed after 1 or 3 weeks of the weathering test. Until then, an oil-based coating film had protected the wood sufficiently, but after 6 weeks the wood was fully defoliated to its non-homogenous thickness, which was caused by the presence of large oak vessels, and by the effects of specific oak tannins. Using transparent hydrophobic coatings can prolong the service life of the exteriors of wood products by decreasing their moisture content. Without proper construction protection against rainwater, the hydrophobic coating itself cannot guarantee the preservation of the natural appearance of wood exteriors.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Efficacy of Hydrophobic Coatings in Protecting Oak Wood Surfaces during Accelerated Weathering

et al. 2017

View full text Add to dashboard Cite

show abstract

“…In fact, ΔE* showed values above 12 in all cases, regardless of the species or finish (Figure 2), that means a complete change of color. This variation between the two weathering conditions is attributable to the fact that with NW there is constant variability of solar radiation (different wave lengths applied: NW produces higher wave length), humidity, rainfall, pollution, and biotic agents that accelerate the color degradation process, while with AW those conditions are controlled, and the influence comes mainly from UV rays (George et al 2005, Sivrikaya et al 2010. In this regard, Creemers et al (2002) pointed out the difficulty of reproducing the natural environmental conditions in an artificial test inside a chamber.…”

Section: Color Change After Exposurementioning

confidence: 99%

Optical performance of finished and unfinished tropical timbers exposed to ultraviolet light in the field in Costa Rica

Salas

Moya

Vargas-Fonseca

2014

Wood Material Science & Engineering

View full text Add to dashboard Cite

This study evaluated wood color change (ΔE*) and the surface quality in 10 tropical wood species painted with three finishes (composed of wax and polyurethane). Two weathering conditions were tested: natural weathering (NW) and artificial weathering (AW). The results showed that the application of these finishes, decreased the luminosity (L*), increased the redness (a*) and the yellowness (b*) parameters in all species. ΔE*, after weathering exposure, was affected significantly by L*, a*, and b, whereas for finished or pretreated wood, L* and b* are the main parameters affecting ΔE* in the 10 tropical species studied. ΔE* values found in different finishes and pretreatments are cataloged as total change of color. Other important results were that tropical light colored timber with natural pretreatment produced higher ΔE* than dark colored timber. The stains and fungal development were observed in polyurethane finishes in NW, but not in AW. The irregular and mosaic flaws were not observed in any kind of finish or pretreatment of surface. The values of the quality index created, which considered long and short lines and switch flaws, were lowest in NW and in waxy finish, while the highest value was obtained with the polyurethane finish.

show abstract

“…These agents may result in a reduction of wood's mechanical and physical properties, as well as micro-cracks, discoloration, and other aesthetical defects in the wood's surface (Feist 1982(Feist , 1990Evans 2008). Suitable types of pigments (Reinprecht and Pánek 2013) or UV-absorbing additives in transparent coating systems can stabilize the color of painted solid wood and are known to decrease or slow down the degradation on its surface (De Meier 2001;Gobakken and Lebow 2010;Syvrikaya et al 2011;Forsthuber et al 2013;Pánek and Reinprecht 2014). Currently, discovering and testing the best coating system for individual applications is of interest in the field (Oltean et al 2010;Grüll et al 2011Grüll et al , 2014Sandak et al 2013).…”

Section: Introductionmentioning

confidence: 99%

Effect of the Number of UV-Protective Coats on the Color Stability and Surface Defects of Painted Black Locust and Norway Spruce Woods Subjected to Natural Weathering

Pánek

Reinprecht

2016

BioResources

View full text Add to dashboard Cite

This paper utilized 12 coating systems, based on an acrylate and a hydrophobic polymer, with the addition of light pigments, nano-sized polyvalent metal (AsS-chelate complex) for ultraviolet protection, and iodopropynyl butylcarbamate fungicide. This study deals with the impact of the number of coats on the color stability and the surface defects of painted black locust (Robinia pseudoacacia L.) and Norway spruce (Picea abies Karst L.) woods after up to three years of natural weathering, at a slope of 45°. The best coating system was created from three coats, which consisted of two pigmented acrylates (PerlColor) and one transparent hydrophobic water-repellent (AquaStop). The total color change, ΔE*, of the weathered surfaces was approximately two times lower when the application involved a pigmented coating system compared with a transparent one. The color stability of the surfaces and their resistance to defects was better when the coating system was applied to black locust wood compared with spruce wood. Smoother surfaces of wood before painting resulted in a higher resistance against cracking and other defects caused by natural weathering; however, the effect of the initial wood roughness on the color stability of painted woods during natural weathering was usually negligible.

show abstract

Natural weathering of oak (Quercus petrae) and chestnut (Castanea sativa) coated with various finishes

Cited by 26 publications

References 18 publications

Efficacy of Hydrophobic Coatings in Protecting Oak Wood Surfaces during Accelerated Weathering

Efficacy of Hydrophobic Coatings in Protecting Oak Wood Surfaces during Accelerated Weathering

Optical performance of finished and unfinished tropical timbers exposed to ultraviolet light in the field in Costa Rica

Effect of the Number of UV-Protective Coats on the Color Stability and Surface Defects of Painted Black Locust and Norway Spruce Woods Subjected to Natural Weathering

Contact Info

Product

Resources

About