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European Journal of Applied Sciences – Vol. 13, No. 02
Publication Date: April 25, 2025
DOI:10.14738/aivp.1302.18510.
Sahin, C. K., & Merdan, R. (2025). Properties of Clear Coated Spruce (Picea orientalis) and Beech (Fagus orientalis) Woods for
Evaluating Outdoor Utilizations. European Journal of Applied Sciences, Vol - 13(02). 165-175.
Services for Science and Education – United Kingdom
Properties of Clear Coated Spruce (Picea orientalis) and Beech
(Fagus orientalis) Woods for Evaluating Outdoor Utilizations
Candan Kus Sahin
Suleyman Demirel University, Architecture Faculty,
Department of Landscape Architecture Isparta, Turkiye
Rahim Merdan
Isparta University of Aplied Sciences, Keçiborlu Vocational School,
Department of Interior Design, Isparta, Turkiye
ABSTRACT
It has become an important issue for protecting wood that is not harmful to users,
while wooden design elements provide many opportunities and amenity to visitors.
Some new types of wood-protecting agents have gained importance due to their
low-toxic chemical formulations. The study presents the experimental study on
outdoor exposure impact on clear coated of two different of Spruce and Beech wood
species. It was found that increasing coating number is usually having positive
effects, lowering the water absorption of both spruce and beech woods. The lowest
water absorption value of 1.7% found at fifth-time coated beech wood, which shows
approximately 97.2% lower than the control sample. However, increasing coating
time (durations) was found to have further lowering effects on water absorption for
beech wood species. It was found that the three-month duration of weathering was
not affected by the surface scratch resistance (hardness) of control spruce and
beech woods, while it is usually increasing effects on waterborne varnish-treated
samples regardless of treatment conditions. This is clearly indicating
physicochemical modification and creating tension on wood surfaces in outdoor
conditions. However, weathering significantly affects the surface color and gloss
properties of selected wood samples. The increasing coating layer was found to be
not affected by improving lightness values for spruce wood. The similar trend was
also observed with treatment time up to 3.0 min, and beyond this level, the wood
surfaces were found to be lighter (ΔL: + values). Moreover, varnish treatment
variables (coating layer and time) were also not any improvement effects found for
beech wood. The lowest ΔL value of-9.78 (in metric) was found for sample Be,
followed by B4 (ΔL:-9.38) and B5 (ΔL:-9.0), samples, respectively. It is important
that the surface total color difference (ΔE) of wood substrates appeared to be well
correlated with coating number and time of duration for both spruce and beech
woods. It was realized that increasing the coating number is not effective for
improving gloss properties for spruce wood, while some variations in glossiness for
beech wood could be realized by changing the treatment parameters.
Keywods: Waterborne varnish, landscape elements, beech, spruce, weathering, color
properties.
INTRODUCTION
While the landscape describes an environment, consists of mostly greenish infrastructures, the
architecture evokes a constructive work that was completed from the very beginning and will
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age over time [1,2]. It has already been well established that wooden material is an effective
material for both architects and users in planning space by positively addressing people's
feelings, particularly aesthetic features, which are very important even though the pattern
changes according to the cutting direction of the wood [1-3]. It has well-presented that wood
can be blended naturally with landscape elements to create a masterpiece with challenging
projects. Because of its versatility, variety of natural colors, and flexibility properties, it
could be used in numerous applications to provide a natural way to add value with a level
of warmth and soften with possibilities for creating unique elements [1,4,5]. Some of the
examples of areas where wooden materials are generally preferred are urban and
neighborhood parks, residential gardens, children's playgrounds, sports fields, squares, zoos,
curbing structures, garden beds, walkways, retaining walls, borders and edgings, pergolas,
planter boxes, and so on. However, wood can act as the focal point of green infrastructures,
gardens, yards, and other landscape elements [1-5]. Hence, wood could be preferred for
multiple purposes in landscape architecture applications in interior and exterior spaces,
creating options for designers for the place of use, usage expectations and desires thanks to its
many types [1,3,5].
However, the use of wood in interior and exterior design is only possible with well-known wood
materials. The use of the material in design disciplines will be possible by revealing its relations
with other materials, extending its usage life, and revealing the properties of wood in terms of
aesthetics and functionality [1,6,7]. Moreover, landscape architects should be considered
environmental products that measure and verify the life cycle of products with the need to
convince the people to do it. In this context, selecting the correct surface coating agent can
enhance the beauty of wood pieces, which requires considering the dominant tones in the finish
[1,4,5].
There have been numerous surface protective agents, available on the market. But it should be
considered the right choice in forming a protective layer in accordance with the end use of the
wood material. The most commonly used varnish types are two-component solvent-based (oily
varnishes) that are usually cured by a combination of both physically and chemically [4,5, 8-
10]. But these types of agents contain some toxic chemicals (volatile organic compounds; VOC),
which are released (emitted) during the service of wood products. Therefore, many varnish
types with more environmentally friendly formulations have emerged recently.
The water-based (waterborne) varnish systems, whose solvent is water instead of oil or
alcohol, have become increased gradually in recent years [9,11,12]. Although these systems
have some advantages over synthetic solvent-based varnish systems, they also have some
drawbacks that their effectiveness is limited when applied to only a single layer, could cause
some discolorations on certain woods (tannin contains woods), may not be effective for some
wood types (resinous woods), and needs to apply multiple layers for effective protection.
Numerous studies have already been conducted for selecting and application of wood
substrates for outside use [1, 4,5, 9-13]. It was reported that hardwood and softwood species
show a systematic trend to surface discoloration that occurs and is clearly visible as a natural
texture with natural weathering progress. However, the degree of changes varies with different
wood species [3-5].
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Sahin, C. K., & Merdan, R. (2025). Properties of Clear Coated Spruce (Picea orientalis) and Beech (Fagus orientalis) Woods for Evaluating Outdoor
Utilizations. European Journal of Applied Sciences, Vol - 13(02). 165-175.
URL: http://dx.doi.org/10.14738/aivp.1302.18510.
Although numerous literatures can be found for surface protective agents for woods, a
systematic approach for the application of water-based varnish systems on specific woods
under outdoor conditions is clearly needed. To find out, selected wood specimens were
subjected to waterborne varnish treatment and used to determine resistance against natural
weathering conditions. After specific time to outdoor exposure, the level of photo-discoloration,
surface hardness and water absorption properties were determined based on controls.
Therefore, the objective of this study is to discuss some of the most common concepts of surface
protection of wood in the context of weathering and suitability for outdoor use, emphasized in
landscape applications. Their importance in predicting the selected wood-weathering
interactions of two different species is discussed herein.
MATERIAL AND METHODS
Spruce (Picea orientalis) and Eastern Beech (Fagus orientalis) woods were selected for
investigation. The spruce and beech woods were acquired from the Black Sea region in Turkey.
The samples were cut into small pieces (5x5x1 cm) and dried in laboratory conditions to an air- dry level (12%) before the experiments. A waterborne type colorless varnish used in this study
was purchased from a retail store. The varnish was used as an emulsion formulation that
belonged to the company’s prospective, as supplied without any further purifications.
The varnish applications on samples were carried out for two different procedures. In one
procedure; in a soaking for 1 to 5 minutes, separately, then the drying was carried out at room
temperature for 8 hours. In the second procedure, in a soaking for 1 to 5 times, separately, the
drying was carried out in each stage for 2 hours and final drying in a room temperature for 8
hours. The all varnish-treated samples were soaked in distilled water at room temperature (23
°C, ±2) for 24 hours, and water absorption (WA%) was calculated. The water absorption
measurements were made with a digital balance, accurate to ± 0.01 gr. After the termination of
each experiment, the percentage maximum water intake was calculated by using the following
equations:
Max. water absorption (%) = 100*(Wet weight - Oven dry weight)/Oven dry weight (1)
The natural weathering tests were conducted on both control and waterborne varnish treated
samples for three months of duration on the south side of Sobu Heights in Isparta, Turkey. The
coating film hardness was determined by the pencil hardness (scratch resistance) test
according to the standard ASTM D3363. This testing checks one standard for film hardness by
comparing the ability of a graphite/clay pencil led to scratch the cured film. In the instrument,
the pencil is held firmly against the film at a 45° angle and pushed away from the operator. The
hardest pencil is applied first. The first pencil that does not mark the film before being marked
determines the “pencil hardness” of the film. This is expressed by the number and/or letter
denoting the hardness of the pencil.
Wood color studies are generally quantified by the CIE L*, a*, b* standard (1976) created by the
Commission Internationale de l’E ́clairage with a three-axis system, i.e., lightness (L*) from 0%
(black) to 100% (white); a* from green (-a) to red (+a); and b* from blue (-b) to yellow (+b).
The CIE color parameters of L*, a*, and b* were determined for un-weathered control and three
month weathered samples by the CIE L,a,b (1976), and their corresponding variations with the
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treatments, i.e. ΔL*, Δa*, and Δb*, were calculated automatically by instrument. The total color
difference of samples (ΔE*) with functions of L*a*b*, calculated as following equations;
ΔE* = (ΔL2 + Δa2 + Δb2)
1/2 (2)
A portable X-rite SP68 spectrophotometer was used to measure all colorimetry measurements
of samples. The instrument was calibrated with white and black standards. The measurements
were made using a D65 illuminant and a 10-degree standard observer. The three measurements
for each treatment sample (conditions) of the wood species were made, and average color
values were calculated. The surface whiteness and yellowness color properties were also
determined according to standard ASTM E-313, and ASTM D-1925, respectively. The gloss
measurements were carried out with the Glossgard II. gloss meter (600).
While many combinations were utilized during the surface treatment and natural weathering
procedure of wood samples, some code numbers and abbreviations were established
throughout the study, given in Figures and Tables. The wood samples shown in Figures and
Tables are: B: Beech; S: Spruce; 1,2,3,4 and 5: one-, two-, three-, four-, and five-time coatings
(number of coatings); a,b,c,d and e: control, one-, two-, three-, four-, and five minute soaked
samples. Figure 1 shows some representative of small wood samples used in this study.
Figure 1: Control and treated small wood samples
RESULTS AND DISCUSSIONS
Wood-based design elements have been preferred in many architectural planning purposes
due to their aesthetic properties. It has already well established that surface treated or natural
wood can be degraded, especially those left outdoors for a long time, such as well examples are
shown in Figure 2 (a-f). The Figure 2 clearly shows the desired appearances changed depends
on the placement of sitting elements. As a result of those changes, the wooden sitting elements
began to exhibit various level of discolorations after outdoor exposure (Fig.2c-f). In certain
circumstances, the effects of atmospheric conditions (weathering or light radiation) are likely
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Sahin, C. K., & Merdan, R. (2025). Properties of Clear Coated Spruce (Picea orientalis) and Beech (Fagus orientalis) Woods for Evaluating Outdoor
Utilizations. European Journal of Applied Sciences, Vol - 13(02). 165-175.
URL: http://dx.doi.org/10.14738/aivp.1302.18510.
to play a considerably greater part for discoloration of wooden materials. The samples 2c, d, e
and f appeared to show higher amount of color change compare to Fig. 2a, after outdoor
exposure.
Figure 2: Outdoor exposured some clear coated wooden sitting elements (a, b and c: well
protected sitting elements, d, e andf: peeled off transparent sitting units)
It is well known that water penetration into wood is very sensitive to the surface coating layer,
and this must be taken into account for the measurement of the water intake. The water
absorption properties of weathered spruce and beech samples at two different treatment
conditions (Coating number and soaking time) in waterborne varnish are presented in Figures
3-4, respectively. It appears that there is a relatively inverse relationship with both treatment
conditions for both types of woods. The highest water absorption of 111.7% was found for the
spruce control sample (S0; untreated), while the lowest value of 4.8% observed with the fifth- time coated sample (S5). Increasing treatment time is also having positive effects, lowering
water absorption (Figure 3).
Figure 3: Treatment conditions effects on weathered spruce wood
Moreover, a less similar trend was also observed for beech woods (Figure 4). The lowest water
intake of 1.7% found at the fifth-time coated sample (B5) which indicates approximately 97.2%
lower value compared to the untreated control sample (B0). The increasing varnish treatment
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time also has further effects, lowering water absorption for beech samples. These results could
be expected, considering lowering water absorption well correlated with coating layer
thickness and/or varnish layer allowed to be deeper penetration into samples. These are also
in good agreement with the results reported surface treatment agent variables and treatment
conditions effects on wood substrates (2,4,5,14,15].
Figure 4: Treatment conditions effects on weathered beech wood
The resistance of varnish layers against scratching is usually called surface hardness. In this
sense, the comparatively scratch resistance of spruce and beech woods, measured with a pencil
hardness instrument, is given in Table 1. The control beech and spruce woods showed the
highest hardness and were not affected by the weathering. The only one level higher scratch
resistance was found for weathered Sa (4H) and Sb samples (5H), respectively. However, all
weathered beech woods show one-level higher scratch resistance values at counterpart
controls. Surprisingly, varnish-applied and then weathered samples had usually higher scratch
resistance than control samples. It could be explained that the surface hardness (Pencil
hardness test) is a property of a coating film, and measured hardness is influenced by the
substrate hardness. It has already been well predicted that the harsh outdoor conditions could
have effects on both chemically and physically. These changes could create tension on the
surface before erosion and/or cracking, which may be increasing effects on surface hardness at
various levels. The experimental results found in this study clearly support this hypothesis.
Table 1: The waterborne varnish treated samples subjected to weathering procedures
Spruce Control Weathered Beech Control Weathered
S0 5H 5H B0 6H 6H
S1 3H 4H B1 3H 4H
S2 2H 2H B2 2H 3H
S3 3H 3H B3 2H 3H
S4 3H 3H B4 3H 4H
S5 3H 3H B5 2H 3H
Sa 3H 4H Ba 3H 4H
Sb 4H 5H Bb 2H 3H
Sc 3H 3H Bc 2H 3H
Sd 4H 4H Bd 3H 4H
Se 4H 4H Be 2H 3H
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Sahin, C. K., & Merdan, R. (2025). Properties of Clear Coated Spruce (Picea orientalis) and Beech (Fagus orientalis) Woods for Evaluating Outdoor
Utilizations. European Journal of Applied Sciences, Vol - 13(02). 165-175.
URL: http://dx.doi.org/10.14738/aivp.1302.18510.
The comparative CIE L*, a*, b* colour properties of protective coating applied and weathered
wood samples are shown in Table 2. The measured results confirm that color properties
changed considerably. For spruce wood; it can be seen that the increasing coating number has
not any positive effects for lowering lightness values that all ΔL value found to be negatives.
This clearly implies that wood surfaces turn to darkish color regardless of coating thickness.
However, the similar results have also found with treatment time up to 3.0 min that beyond this
level, the wood surfaces found to be lighter (ΔL: + values). The lowest ΔL value of -7.83 was
found with sample Sc, followed by Sb (ΔL: -9.68) and S4 (ΔL: -3.69) while the lighter surfaces
were found with samples Sd (ΔL: 2.73) and Se (ΔL: 9.17), respectively. For beech wood; the
lightness properties of the samples from both procedures were found to be lowering (ΔL:-
values) in all conditions and no any positive lightness values were found. Moreover, the lowest
ΔL value of-9.78 was found for sample Be and followed by B4 (ΔL:-9.38) and B5 (ΔL:-9.0) while
the lowest changes was found with sample B3 (ΔL: -5.38).
However it is notable that surface redness/greenish color properties (Δa*) of spruce samples
show higher redness (Δa: + values) in all conditions than controls. The highest redness value of
Δa: 1.81 was found with sample Sc followed by Se (Δa:1.80) and Sb (Δa:1.70), respectively. Like
lightness, similar trend was also found for redness/greenish properties for beech samples that
that beyond 3.0 min treatment time, the beech wood’s surface found to be more reddish color.
The more greenish like color was also found with sample Bb (Δa:-0.98) and followed by B1 and
B3 (Δa:-0.78), respectively.
For yellowness/blueness properties (Δb*), for both spruce and beech samples show higher
yellowness (+Δb) values than control in all treatment conditions. The highest yellowness value
of Δb: 5.06 found for samples S1 and Sa for spruce and Δb: 6.97 found for sample Bc for beech.
Surface whiteness (E-313) and yellowness (D-1925) values usually correlate CIE L*,a*,b*
properties that all weathered samples show lowering whiteness while increaing yellowness
color properties regardsless of treatment conditions for both spruce and beech wood samples.
These results could be expected considering wood having different anatomical and chemical
properties could influence treatments differently. Hence, it should be suggested that the
different wood species might influence the wood-color interactions to some degree differently
[1,9,13,16]. However, a number of researchers has already reported that yellow color of
weathered woods was mainly due to oligomeric chromophores, which probably came from the
chromophores of the lignin moiety and lignin is the main constituent responsible for the
discoloration of woods [17].
Table 2: Surface color change of wood species exposure in outdoor conditions (Values
in metric)
Samples ΔL Δa Δb E313 Whiteness D1925 Yellowness
Spruce Woods
S1 -3.07
(2.48)
0.99
(0.11)
5.06
(1.06)
-9.87
(2.62)
10.92
(1.11)
S2 -2.20
(0.62)
0.65
(0.24)
3.45
(0.20)
-6.29
(0.59)
8.37
(0.63)
S3 -2.94
(0.52)
0.88
(0.22)
3.08
(0.44)
-5.26
(0.62)
7.27
(1.69)
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S4 -3.69
(0.36)
0.28
(0.24)
4.33
(0.71)
-7.20
(1.15)
10.53
(1.67)
S5 -0.19
(1.18)
0.28
(0.13)
4.11
(0.82)
-8.52
(2.22)
7.81
(0.89)
Sa -3.07
(2.48)
0.99
(0.11)
5.06
(1.06)
-9.87
(2.62)
10.92
(1.11)
Sb -7.68
(0.53)
1.70
(0.07)
4.97
(0.80)
-8.55
(1.59)
14.75
(1.47)
Sc -7.83
(0.94)
1.81
(0.19)
3.83
(0.46)
-6.24
(5.15)
13.04
(0.68)
Sd 2.73
(0.31)
1.37
(0.48)
3.38
(0.74)
-5.31
(1.55)
11.78
(1.70)
Se 9.17
(0.80)
1.80
(0.24)
3.54
(1.54)
-5.01
(3.23)
13.37
(2.52)
Beech Woods
B1 -5.55
(2.53)
-0.78
(0.51)
6.13
(1.28)
-12.52
(3.42)
13.85
(0.40)
B2 -5.79
(0.67)
-0.69
(0.64)
5.30
(0.80)
-10.32
(1.24)
12.67
(2.64)
B3 -5.01
(1.34)
-0.78
(0.18)
4.9
(0.27)
-9.85
(0.67)
11.32
(1.14)
B4 -5.84
(0.42)
-0.8
(0.42)
4.7
(0.12)
-9.18
(0.09)
11.47
(0.14)
B5 -9.0
(1.89)
-0.44
(0.32)
4.44
(0.35)
-7.56
(1.13)
14.61
(1.56)
Ba -5.55
(2.53)
-0.78
(0.51)
6.13
(1.28)
-12.52
(3.42)
13.85
(0.40)
Bb -6.67
(0.72)
-0.98
(0.23)
5.99
(0.18)
-11.70
(0.14)
14.43
(1.62)
Bc -8.06
(2.09)
0.12
(0.88)
6.97
(0.32)
-12.86
(1.23)
18.18
(2.54)
Bd -9.38
(0.69)
0.67
(0.09)
6.06
(0.46)
-10.71
(1.07)
18.07
(0.36)
Be -9.78
(1.97)
0.61
(1.05)
6.06
(0.74)
-10.55
(1.95)
18.33
(2.40)
*The numbers in parentheses are standard deviations
Many researchers suggested that ΔE was could be a better predictor than CIE, L*,a*,b* for most
property of woods [17-20]. The surface total color difference (ΔE) of wood substrates appeared
to be well correlated with coating number and duration time for spruce and beech woods
(Figure 5). However, beech wood appeared to more sensitive for discoloration than spruce
wood at similar treatment conditions. These comparisons between the treatment variables and
the measured results reveal that the color-change response of a wood can be accurately
predicted based on the treatment conditions.
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Sahin, C. K., & Merdan, R. (2025). Properties of Clear Coated Spruce (Picea orientalis) and Beech (Fagus orientalis) Woods for Evaluating Outdoor
Utilizations. European Journal of Applied Sciences, Vol - 13(02). 165-175.
URL: http://dx.doi.org/10.14738/aivp.1302.18510.
Figure 5: Surface coating conditions effects on total color changes (ΔE) of spruce and beech
wood
The measured color values presented above are clearly indicated that the color changes of a
coated wood substrate are a phenomenon and contains many variables (e.g., wood-based,
varnish-based, treatment condition-based) and very difficult to explain all changes in a one
way. But it is clear that color modification could be decreased by choosing optimal treatment
conditions.
Figure 5: The coating conditions effects on glossiness (Gu) of weathered spruce wood
Figure 6: The coating conditions effects on glossiness (Gu) of weathered beech wood
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A comparative summary of the surface glossiness changes of weathered samples with varnish
treatment (coating time and number) are shown in Figure 5 (for spruce) and Figure 6 (for
beech). It could be seen that increasing coating number not effective for protecting gloss
properties for spruce wood. Similar trend was also found with coatings that increasing coating
layer is not effects protecting glossiness. The highest gloss value of 4.3 Gu was found with only
one minute and only once coated control spruce sample. However, some variations in
glossiness for beech wood could be realized by changing the treatment parameters. In general,
increasing coating layer provides effective protection of glossiness up to three level (3.17 Gu)
then it is decreases. Moreover, it appears to be some level correlated with treatment time as
well.
CONCLUSION
The wood consumers and producers have become to avoid the use of toxic chemicals in their
close environments. In this respect, development of new technologies based on low
environmental impact agents and sustainable principles are emerging issue in recent years.
Waterborne varnish which contains reduced toxic solvent in its formulations have become
favor surface coating agents in many applications. However, experimental results show how
beech and spruce wood species respond in real time at environmental conditions according to
surface clear coating variations, changing their surface properties. These issues are very
important during urban furniture establishments with wood-based elements while it may
affect the integrity of the wooden components and, ultimately, the integrity of the entire design
practices. The experimental results clearly stated that water intake and surface discoloration
usually correlated with number of coatings and varnish treatment durations. This may very
important and should be considered when established wooden landscape design elements to
outdoor condition.
References
[1] Winterbottom, D.M. Wood in the landscape. A practical guide to specification and design, John &Wiley Sons,
NY.2000. pp 216.
[2] Sahin, C. K., Onay, B. Alternative wood species for playgrounds wood from fruit trees. Wood
Research, 2020. 65(1), 149-160.
[3] Sahin, C. K., Topay, M., Var, A. A. A study on suitability of some wood species for landscape applications:
surface color, hardness and roughness changes at outdoor conditions. Wood Research, 2020. 65(3), 395-
404.
[4] Sahin, C. K., Merdan, R. Surface behaviors of pine wood (Pinus nigra) after short-term weathering: urban
furniture suitability investigation. European Journal of Applied Sciences, 2025a. 13(1): 98-109.
[5] Sahin, C. K., Merdan, R. Outdoor exposure effects on different formulated clear coats of wood as sustainable
urban design material. European Journal of Applied Sciences, 2025b. 13(1): 110-121.
[6] Bowyer J.L, Shmulsky, R., Haygreen J.G. Forest Products and Wood Science-An Introduction. Fourth edition,
Iowa State University, Ames, IA, 2003. 553p.
[7] Hoffman, R., Hendricks, L. T. Selecting preservative treated wood (with special emphasis on landscape
timbers), Agriculture Extension Service, 1982. Extension folder-642-1982, University of Minnesota, MN. 1-8
p.
[8] Auer, M. M. Wood finishing and refinishing. Creative Homeowner Press, New Jersey, NJ. 1982. pp 142.
Page 11 of 11
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Sahin, C. K., & Merdan, R. (2025). Properties of Clear Coated Spruce (Picea orientalis) and Beech (Fagus orientalis) Woods for Evaluating Outdoor
Utilizations. European Journal of Applied Sciences, Vol - 13(02). 165-175.
URL: http://dx.doi.org/10.14738/aivp.1302.18510.
[9] Cassens, D., Feist, W. Exterior wood in south, selections applications and finishes, USDA Forest Service,
Forest Products Laboratory, General Technical Report FPL-GTR-69, 1991. Madison, WI. USA.
[10] González-Laredo, R. F., Rosales-Castro, M., Rocha-Guzmán, N. E., Gallegos-Infante, J. A., Moreno-Jiménez, M.
R., Karchesy, J. J. Wood preservation using natural products, Madera y bosques, 2015. 21, 63-76.
[11] Feist, W. The outdoor finish, how and when to paint or stain, Fine housebuilding, 1985. pp. 54-55.
[12] Özgenç, Ö., Durmaz, S., Şahin, S. and Boyaci, I. H. Evaluation of the weathering resistance of waterborne
acrylic-and alkyd-based coatings containing HALS, UV absorber, and bark extracts on wood
surfaces. Journal of Coatings Technology and Research, 2020. 17(2), 461-475.
[13] Williams, R. S., Feist W. C. Finishing wood decks, Wood design focus, 1993. 4 (3): 17-20.
[14] Budakçı, M., Sönmez, A. Bazı ahşap verniklerin farklı ağaç malzeme yüzeylerindeki yapışma direncinin
belirlenmesi, (Turkish, Abstract in English) Gazi Üniversitesi Mühendislik Mimarlık Fakültesi Dergisi, 2010.
[15] Gezer, İ. Ağaç malzemeye uygulanan ısıl işlemin su bazlı verniklerdeki etkilerinin incelenmesi, (MSc thesis,
Turkish Abstract in English), Dumlupınar Üniversitesi, Kütahya-Turkiye, 2009.
[16] Mc Donald, K.A., Falk, R.H., Williams, R.S., Winandy, J.E. Wood decks, materials, construction and finishing.
Forest Products Society, Madison, WI. 1996. pp 93.
[17] Tolvaj, L., Faix, O. Artificial ageing of wood monitored by drift spectroscopy and CIE Lab color
measurements. Holzforschung, 1995. 49(5):397-404.
[18] Janin, G., Gonzales, J.C., Ananias, R., Charrier, B., Silva, G., Dilem, A.: Aesthetics appreciation of wood colour
and patterns by colorimetry. Part 1. Colorimetry theory for the CIELAB system. Maderas: Ciencia y
Tecnología, 2001. 3(1-2):3-13.
[19] Palashev, Y.: Change in the wood colour under the influence of climatic factors. Naukaza Gorata, 1994.
31(2): 65-71.
[20] Pastore, T.C.M., Santos, K.O., Rubim, J.C Spectrocolorimetric study on the effect of ultraviolet irradiation of
four tropical hardwoods. Bioresource Technology, 2004. 93(1):37–42.