Integration of Traditional Methods and Modern Technologies in the Preservation and Restoration of Wooden Artifacts of Kazakh and Turkic Culture

1.1 Research Objective

The motivation for this study arose from the need to develop a scientifically grounded and practically applicable methodology for the restoration of wooden artifacts belonging to Kazakh and Turkic cultures. Although individual practices exist, to date, there is no unified protocol adapted to ethnographic objects exhibiting high degrees of biodeterioration and complex decorative structures.

The goal of this research is to determine optimal strategies for combining traditional methods and modern technologies, aimed at the preservation and restoration of wooden artifacts of Kazakh and Turkic origin, in such a way as to maximize the retention of their authenticity and historical value. The working hypothesis posits that integrating traditional restoration techniques, rooted in material-property knowledge and centuries-old practices, with contemporary methods of wood analysis and consolidation will enable the development of an effective and minimally invasive approach for safeguarding these wooden artifacts.

The specific objectives of this study are:

1. To conduct non-invasive diagnostics of the selected artifacts’ condition using 3D scanning, radiography, and computed tomography;

2. To identify and classify both traditional and modern materials employed for consolidation, protection, and restoration of wood;

3. To perform laboratory experiments assessing the efficacy of restoration approaches on representative damage scenarios;

4. To develop a comprehensive restoration methodology that synthesizes traditional knowledge with modern technologies;

5. To formulate recommendations for the application of combined approaches, thereby ensuring sustainable preservation of wooden artifacts in museum and exhibition practice.

2.1 Research Design and Sampling

The present study is aimed at the development of a comprehensive restoration strategy that integrates traditional approaches with contemporary technologies, specifically applied to wooden artifacts of Kazakh and Turkic cultural provenance. The experiment comprised four sequential stages. At the first stage, eight artefacts were selected and systematized, and subsequently classified into three functional groups. The second stage employed non-destructive diagnostic methods, including three-dimensional scanning with an Artec Eva scanner (0.1 mm resolution), computed tomography using a GE Phoenix system (70–80 μm accuracy), and visual inspection to complement the instrumental assessment. At the third stage, laboratory test parameters were established: five repetitions per series, temperature maintained at 22 ± 2 °C, relative humidity at 55 ± 5 %, and illumination at 500 lux. The fourth stage involved statistical analysis conducted in SPSS 26.0. The sample consisted of eight wooden artefacts representing key features of the material culture of Kazakh and Turkic peoples. Selection criteria included: documented provenance within a Kazakh or Turkic ethnocultural context; retention of primary wooden structure without substantial modern restoration interventions; presence of visible or latent damage requiring conservation; and compliance with museum registration and storage requirements as stipulated by the Ministry of Culture and Sports of the Republic of Kazakhstan. The selection process was carried out using holdings from the Central State Museum of the Republic of Kazakhstan (Almaty).

The artefacts were classified into three categories according to their functional purpose:

Yurt Elements: a carved wooden door jamb; a kerege lattice panel featuring original mortise-and-tenon joints; and a dome ring (shanyrak) missing three radial components.

Musical Instruments: a dombra with a deformed soundboard and evidence of neck replacement; and a kobyz exhibiting a cracked pegbox socket and disruption of its lacquer coating.

Household Objects: a carved wooden chest with loss of a section of its facade panel; a wooden bowl showing signs of biodeterioration; and a ritual vessel incorporating bone inlays and remnants of prior restoration work.

These artifacts were chosen on the basis of their historical significance, state of preservation, and the feasibility of applying both traditional and modern restoration techniques. Each object underwent an initial visual inspection and was documented within an electronic database, which records information regarding provenance, current condition, and the anticipated conservation tasks.

2.2 Methods of Instrumental Analysis

Non-invasive diagnostic techniques were employed to obtain objective information regarding the current physical condition of the artifacts. Each object underwent 3D scanning using a portable Artec Eva scanner, which yields high-precision digital surface representations, capturing microcracks, deformations, and surface abrasions. Additionally, radiographic imaging was performed on six artifacts exhibiting pronounced signs of internal degradation. Computed tomography (CT) with a resolution of up to 80 µm was conducted using a GE Phoenix v|tome|x m tomograph; this enabled the acquisition of cross-sectional images of the wood’s internal structure, revealing evidence of biodeterioration, shrinkage cracks, and prior restoration interventions. The resulting datasets were processed using Geomagic Design X (for geometric reconstruction) and VGStudio MAX (for defect and material-structure analysis).

Quantitative criteria corresponding to the objectives of each restoration phase were developed to evaluate the efficacy of the methods and materials employed. Consolidation efficiency was assessed by measuring penetration depth (in millimeters), changes in surface microhardness (on the HV 0.1 scale), and resistance to biological attack. Microhardness testing was carried out with a Shimadzu HMV-G Series microhardness tester, following ISO 6507. Biological resistance was determined by quantifying the mass loss of wood samples exposed to the model fungus Trametes versicolor over 21 days under controlled incubation conditions, in accordance with ASTM D2017-81 (modified for museum specimens). Surface-cleaning efficacy was evaluated by measuring color change (ΔE on the CIE Lab scale) and by detecting residual contaminants – both visually and at the microscale – using digital microscopy at ×200 magnification. Colorimetric measurements were performed with a Konica Minolta CM-700d spectrophotometer, in compliance with ISO 11664-4:2008(E).

Methods of form restoration (including loss compensation and lamination) were evaluated based on geometric stability parameters – specifically, volumetric and shape alignment – verified on digital 3D models before and after intervention using Geomagic Design X’s deviation-comparison module (with an accuracy of ± 0.05 mm). Additionally, adhesion performance was assessed through pull-off testing in accordance with ISO 4624, and the reversibility of the intervention was examined by verifying the possibility of removing the applied restoration layer without damaging the original wood substrate. Pull-off tests were used to assess the adhesion strength of the materials: Paraloid B72 exhibited 2.8 ± 0.3 MPa, NanoCell M-21 reached 3.2 ± 0.2 MPa, ConsolideX 240 showed 2.9 ± 0.3 MPa, bone glue measured 1.8 ± 0.4 MPa, and larch resin yielded 2.1 ± 0.3 MPa.

2.3 Selection and Classification of Restoration Materials

In the subsequent phase of the study, materials employed in both traditional and contemporary restoration practices for wooden artifacts were selected and classified. Particular attention was given to criteria of compatibility with historical wood, environmental safety, reversibility of intervention, and resistance to biodeterioration. Based on an analysis of ethnographic sources and museum documentation, as well as consultations with master restorers from the Restoration and Conservation Service of the Central State Museum of the Republic of Kazakhstan, substances historically used within Kazakh and Turkic contexts were identified (Table 1).

All materials were procured in accordance with ethnographic sources and prepared by hand in the Conservation and Restoration Laboratory of the Central State Museum of the Republic of Kazakhstan. Biochemical parameters (viscosity, pH, and organic acid content) were determined under laboratory conditions. Control samples were applied to fragments of pine and elm wood – two species most frequently encountered in the artifacts.

Viscosity measurements revealed pronounced rheological differences among the traditional consolidating formulations (Table 2). Beeswax demonstrated the highest flow resistance (12,000 ± 500 mPa s), resulting in limited penetration into the wood but forming a durable protective surface layer. Bone glue exhibited moderate viscosity (450 ± 25 mPa s), making it suitable for localized crack filling. Linseed oil showed low viscosity (55 ± 5 mPa s), enabling deep penetration into the wood structure. The pH values remained near neutral (5.9–7.1), minimizing the risk of hydrolytic degradation. Larch resin contained the highest concentration of organic acids (4.5 ± 0.4 %), providing antimicrobial effects due to its acidic environment. These physicochemical characteristics informed the selection of materials for subsequent restoration procedures.

Modern materials were selected based on the following criteria:

1. Biological resistance (against fungi and insects);

2. Chemical compatibility with wood and traditional substances;

3. Reversibility and visual neutrality (absence of gloss, yellowing, or film formation).

The items chosen from among the tested samples are presented in Table 3.

Each treatment was tested on aged wood samples from the non-exhibition collection (manufacture date approximately 1930–1950, according to museum records). Standard testing protocols were employed to assess penetration, color change (via spectrophotometry), acidity, coating flexibility, and moisture resistance. For preliminary comparison of material efficacy, the following metrics were used: penetration depth (in mm), color change (ΔE on the CIE Lab scale), and degree of reversibility (complete removal without residue). Based on these analyses, six materials (three traditional and three modern) were selected for demonstrating the best overall performance and were recommended for subsequent restorative procedures during the laboratory modeling phase.

Laboratory experiments were then conducted to evaluate the effectiveness of various restoration methods utilizing both traditional and modern materials. The objective of this phase was to compare methods according to their ability to preserve the wood’s structural integrity, maintain aesthetic compatibility, and resist external stressors.

Historical wood samples (spruce and elm), matched in age and degradation level to those of the original artifacts, were used for testing. The laboratory conditions were maintained at 22 ± 2 °C, 55 ± 5 % relative humidity, and an illumination level of 500 lux. The fungus T. versicolor was cultured at 28 °C for 21 days in sterile Petri dishes with a diameter of 90 mm. In each experimental series (n = 5), the following types of interventions were applied:

1. Consolidation: application of adhesive or impregnating formulations.

2. Cleaning: removal of contaminants by mechanical or chemical means.

3. Protection: treatment with antiseptic agents and protective coatings.

Standardized protocols ensured consistency in data collection. Penetration depth was measured on transverse sections (50 μm thick) stained with a 0.1 % rhodamine B solution and examined under an Olympus BX51 microscope at × 100 magnification. Microhardness was determined using a Shimadzu HMV-G21 device, applying a 0.098 N load (HV 0.01 scale) with a 15-second dwell time; 10 measurements were taken for each specimen at 0.5-mm intervals to ensure statistical reliability. Moisture resistance was assessed by placing the samples in a Binder KBF 240 climate chamber (85 % relative humidity, 23 °C) for 72 h, with mass and dimensional changes indicating the degree of hygroscopicity. Reversibility was evaluated by dissolving the applied layers in the appropriate solvent (acetone for Paraloid B72; ethanol for nanocellulose), and ultraviolet inspection confirmed complete removal of the coatings.

2.4 Laboratory Modeling and Testing of Restoration Methods

In the third phase, laboratory experiments were conducted to assess both traditional and contemporary approaches to cleaning, consolidation, and conservation. A total of five methodologies were tested:

1. Consolidation using bone glue followed by surface treatment with beeswax;

2. Impregnation with larch resin in combination with linseed oil;

3. Fixation and consolidation employing Paraloid B72;

4. Injection of nanocellulose (NanoCell M-21);

5. Consolidation of friable wood using ConsolideX 240 solution.

Each treatment was documented in a digital logbook, specifying the parameters of the materials used, exposure time, the extent of observed changes, and any visible side effects. Analysis of variance (ANOVA) revealed statistically significant differences between groups (F(4,20) = 18.3, p < 0.001). Tukey’s post hoc test indicated that NanoCell M-21 and ConsolideX 240 outperformed the traditional materials across all parameters (p < 0.01), while the two modern consolidants did not differ significantly from each other (p = 0.82).

2.5 Statistical Analysis

All digital models and tomographic datasets were processed using Geomagic Design X and VGStudio MAX software. Quantitative parameters of change (e.g., crack depth, volume of lost material) were measured before and after each restoration intervention. The resulting values were compared across experimental groups using the Mann–Whitney U test and one-way analysis of variance (ANOVA) implemented in SPSS 26.0. The significance level (α) was set at 0.05.

2.6 Ethical Considerations

All artifacts were provided by the Central State Museum of the Republic of Kazakhstan with formal consent for non-destructive analysis. All diagnostic and restoration activities were carried out in accordance with the regulations and ethical standards governing the treatment of museum and ethnographic objects (Law of the Republic of Kazakhstan No. 288-VI ZRK “On the Protection and Use of Historical and Cultural Heritage Objects,” December 26, 2019). Only non-destructive methods and reversible materials were utilized. To ensure scientific rigor and alignment with international standards, the research adhered to the guidelines of the International Council of Museums (ICOM).

2.7 Limitation of Research

During the course of this study, certain limitations were identified, arising both from the characteristics of the source objects and from the conditions under which the experimental phase was carried out. The sample comprised artifacts accessible within a single museum collection, thereby constraining the diversity of typological and regional representations of wooden objects from Kazakh and Turkic cultures. Moreover, all restoration procedures were conducted under laboratory conditions on a limited number of specimens, which does not allow full consideration of factors associated with long-term natural aging. Another limitation is the use of non-destructive diagnostic methods, which, despite their high informativeness, do not always permit the detection of chemical changes in the deeper layers of wood. The results of the laboratory experiments require further validation under actual museum operating conditions, and the effectiveness of individual materials must be confirmed over the long term. Long-term performance after five years requires experimental verification, as accelerated ageing tests conducted under laboratory conditions do not always replicate the natural degradation processes that occur in museum environments.

3.1 Comparative Analysis of Restoration Method Effectiveness

The evaluation of each restoration methodology across the selected parameters yielded the following findings:

1. Bone Glue + Beeswax demonstrated the shallowest penetration depth (1.8 mm) and a relatively low surface microhardness (22 HV), indicating weak reinforcement of the wood’s internal structure. The color change (ΔE = 3.4) was among the highest observed, reflecting a pronounced visual impact on the surface. Biological resistance measured 61 %, suggesting that this method is most appropriate for surface-level decorative treatments or minimally invasive conservation tasks.

2. Larch Resin + Linseed Oil performed best among traditional materials: penetration depth reached 2.2 mm, surface microhardness increased to 25 HV, and biological resistance improved to 66 %. The visual alteration (ΔE = 2.9) was lower than that of the bone glue + beeswax treatment, making this combination suitable for the restoration of exposed decorative elements where retention of visual authenticity is paramount.

3. Paraloid B72 (synthetic resin) yielded significant structural reinforcement: surface microhardness measured 34 HV with a penetration depth of 3.9 mm. Biological resistance reached 85 %. Color change remained moderate (ΔE = 1.6), but the formation of a superficial film may be critical for artifacts with an exposed wood texture.

4. NanoCell M-21 (nanocellulose) exhibited superior performance across all criteria: minimal color change (ΔE = 1.2), greatest penetration depth (4.2 mm), highest surface microhardness (38 HV), and maximal biological resistance (91 %). These results indicate that nanocellulose is a highly effective consolidant with minimal visual impact. Its biodegradability and reversibility further establish it as a priority choice in conservation practice.

5. ConsolideX 240 showed characteristics comparable to NanoCell M-21: penetration depth of 4.0 mm, surface microhardness of 36 HV, and biological resistance of 89 %. Color change measured ΔE = 1.4. These findings confirm the material’s efficacy as a universal internal consolidant, particularly in areas exhibiting extensive degradation.

Based on the analysis of all four parameters, modern formulations – especially those based on nanocellulose and consolidating resins – outperform traditional treatments in terms of durability, resistance to biodeterioration, and structural preservation. Notably, nanocellulose offers minimal visual intrusion and superior reversibility. The comparative chart illustrating the effectiveness of the five restoration methods across the evaluated parameters is presented in Figure 4.

Figure 4:

Comparative chart of the effectiveness of five restoration methods according to the evaluated parameters (↓ – lower is better, ↑ – higher is better). Source: author’s design.

A comparative analysis of materials across categories revealed consistent patterns (Table 6). Synthetic consolidants (Paraloid B72, NanoCell M-21, ConsolideX 240) penetrated to depths of 3.9–4.2 mm, approximately twice that of traditional formulations (1.8–2.2 mm). Color change inversely corresponded to technological sophistication: nanocellulose produced minimal discoloration (ΔE = 1.2), whereas bone glue resulted in noticeable yellowing (ΔE = 3.4). Nanocellulose increased microhardness to the highest level (38 HV), exceeding the performance of traditional treatments by 73 %. Biological resistance demonstrated pronounced divergence: Preventol D6 Plus inhibited fungal growth by 95 % due to its biocidal activity, whereas untreated samples were fully colonized by mycelium. Moisture resistance aligned with penetration depth, as consolidated wood absorbed less water and underwent reduced swelling. Reversibility showed categorical distinctions: synthetic polymers dissolved completely in appropriate solvents, while natural adhesives left residual traces. The multiparametric comparison confirms the superiority of modern materials for structural consolidation, with traditional substances remaining suitable for reversible surface treatments.

The comparative analysis of pre- and post-restoration data demonstrated that the implementation of an integrated approach resulted in significant improvements across several key parameters.

Restoration quantitatively improved the structural condition of all artefact types (Table 7). Nanocellulose injection reduced the delamination of the dombra soundboard from 4.0 mm to 0.2 mm, eliminating 95 % of the defect. Surface hardness doubled (18→36 HV), restoring mechanical integrity to a level comparable to untreated wood. Cracks in the kobyz closed completely following the precise application of adhesive. Geometric correction of the shanyrak reduced deviation from circularity by 75 %, with a residual distortion of 3 mm attributable to irreversible fiber compression. Treatment removed 93 percent of the deteriorated material from the chest panel. Statistical significance (p < 0.001–0.01) confirmed that the restoration effects exceeded measurement error. These quantitative improvements demonstrate that combining traditional and contemporary methods yields superior conservation outcomes compared to the use of isolated approaches.

However, the degree of effectiveness varied depending on the chosen methodology and the type of artifact.

1. Bone Glue + Beeswax was primarily applied for localized consolidation of cracks in the Kobyz’s structure, where minimal visual intervention was required. Despite the cultural relevance of this method, the increase in surface microhardness was only 22 HV (a 12 % rise relative to the baseline) and resistance to biodeterioration measured 61 %. Cleaning efficacy and penetration depth were minimal. Nevertheless, this method preserved a high degree of visual integrity of the lacquered surface.

2. Larch Resin + Linseed Oil was employed to infill losses in the decorative carving of the yurt’s door jamb. This treatment yielded more balanced results among traditional techniques: microhardness increased to 25 HV (+16 %), biodeterioration resistance rose to 66 %, and color alteration was moderate (ΔE = 2.9). Penetration depth reached 2.2 mm, which allowed for the consolidation of the upper wood layer while maintaining its decorative qualities.

3. Paraloid B72 was tested during the restoration of adhesive-bonded areas on the ritual vessel, serving as a reversible consolidant for fragment reattachment. The resulting strength gain was 34 HV (+28 %), with biodeterioration resistance of 85 % and minimal visual change (ΔE = 1.6). However, the formation of a superficial film limits its use in areas with exposed wood texture.

4. NanoCell M-21 (Nanocellulose) was applied to the chest’s interior layer, where insect-induced tunnels had been identified. This material exhibited the greatest penetration depth (4.2 mm), raised microhardness to 38 HV (+31 %), and achieved biodeterioration resistance of 91 %. With a low color change (ΔE = 1.2), this method was deemed optimal for restoring load-bearing capacity while preserving visual authenticity. Its biodegradability and reversibility further support its priority status in conservation practice.

5. ConsolideX 240 was used to consolidate the dombra’s soundboard in regions of internal delamination. This treatment demonstrated strong performance: microhardness of 36 HV (+30 %), penetration depth of 4.0 mm, biodeterioration resistance of 89 %, and color change (ΔE = 1.4). These results facilitated the strengthening of the thin, deformed wood layer without altering its acoustic properties.

Each method exhibited varying degrees of effectiveness contingent on the damage type and specific artifact characteristics. The most comprehensive improvements across all parameters – strength, protection, and visual neutrality – were achieved by approaches based on modern biodegradable formulations, notably nanocellulose and consolidating resins. Their application yielded an average increase in microhardness of 31 %, a 54 % improvement in biodeterioration resistance, and a 42 % enhancement in visual cleanliness compared to the initial state. These outcomes validate the appropriateness of their use in restoring ethnographic collections. Empirical data indicate that contemporary materials (particularly NanoCell M-21 and ConsolideX 240) outperform traditional treatments across all criteria, especially in terms of biodeterioration resistance and penetration depth. At the same time, traditional combinations (e.g., resin + oil) yield satisfactory results with significantly less alteration to visual characteristics, which is critical when working with exposed decorative surfaces.

The experimental results confirm the high efficacy of a combined approach that utilizes modern consolidants alongside traditionally employed protective substances. Such combinations provide mechanical strength and protection while minimally impacting the visual and tactile properties of the object. Based on the empirical data obtained from artifact condition analyses and laboratory testing, a comprehensive restoration methodology for wooden objects of Kazakh and Turkic cultural heritage was formulated. This methodology is founded on the principle of integrating traditional artisanal practices with scientifically validated technologies and prescribes a differentiated approach depending on artifact type, damage characteristics, and the required level of intervention.

The methodology is founded upon three primary principles:

1. Predominance of reversible interventions, allowing for the dismantling or removal of restorative materials without damaging the original structure.

2. Minimization of visual and physical impact on the artifact, prioritizing the preservation of patina and original traces of use.

3. Cultural relevance – employing materials and techniques traditionally used within the corresponding historical-ethnographic context, provided they are compatible with modern components.

The stages of the restoration protocol are presented in Table 8.

The enhanced workflow follows a modular structure, with each stage adapted to the specific characteristics of the artefact, ensuring a balance between technological efficiency and the preservation of cultural authenticity. This protocol may be recommended for incorporation into the conservation practices of Kazakh museums and can serve as a methodological foundation for training specialists in ethnographic heritage preservation.

Based on the foregoing analysis, the following recommendations are proposed for the practical implementation of combined restoration strategies:

1. In the restoration of wooden artifacts from Kazakh and Turkic contexts, preference should be given to reversible consolidants with minimal visual impact (e.g., NanoCell M-21, Paraloid B72).

2. The use of traditional materials is permissible for external protective or decorative treatments, provided they are compatible with primary consolidating components.

3. A preliminary instrumental survey (3D scanning, CT) is required to detect concealed defects and to plan interventions with precision.

4. It is advisable to establish a digital archive for each object, comprising a 3D model, a damage map, and a record of all interventions, in order to facilitate monitoring of changes over time.

5. The selection of treatment methods should consider not only physicochemical parameters but also the artifact’s cultural significance, including its ethnographic context and status within the museum collection.

6. These recommendations are designed for adaptation to various artifact categories and may inform the development of national standards for conserving ethnographic wooden heritage.