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Research on the degradation mechanism of coating materials is crucial for the preservation of cultural heritage. The purpose of this study was to evaluate the protective effect of Coromandel coatings on wooden substrates by analyzing their dimensions, weight, adhesion strength, hydrophobicity, and glossiness. The results indicate that after five cycles, the radial moisture expansion rate of the wood specimen is 0.332%, while that of the lacquer specimen is 0.079%, representing 23.8% of the radial moisture expansion rate of untreated wood specimens. This performance is superior to that of the ash and pigment specimens. Across different experimental conditions, the change in the mass of the Coromandel specimens aligns with the trend in their dimensional changes, indicating that moisture absorption and desorption are the primary reasons for dimensional changes. The influence of temperature on mass and dimensional stability is significant only in terms of dry shrinkage rate. After wet and dry cycles at 40 °C, the adhesion strength of the Coromandel specimens decreases the most, with the ash specimens decreasing by 7.2%, the lacquer specimens by 3.2%, and the pigment specimens by 4.5%. Following wet and dry cycles at three different temperatures, the contact angle of the lacquer layers changes by less than 5%, with their contact angle values exceeding 120°. These data indicate that among the Coromandel coatings, the lacquer layer provides the best protection for the wooden substrate, while the ash coating is the most fragile. The degradation rate of the Coromandel specimens increases with rising temperatures. These findings emphasize the critical roles of humidity and temperature in protecting wooden coatings and aim to provide theoretical insights and practical significance for the preservation of wooden artifacts and the assessment of coating performance. [ABSTRACT FROM AUTHOR]

Pyrolysis is an effective way to use abandoned furniture materials. This work dealt with solid wood, particle board, and medium density board obtained from dismantling discarded furniture as experimental materials. Slow pyrolysis was performed at a heating rate of 150 °C/h and pyrolysis temperatures of 400, 500, and 600 °C, and the products were analyzed. With the increase of pyrolysis temperature, the yield of solid products gradually decreased, while the yield of liquid products and non-condensing gases gradually increased. The carbon content in solid products reached 63.6 to 94.4%. The pyrolysis solution was acidic to weakly alkaline due to the different types and contents of adhesives in the three pyrolysis materials. Understanding the yield and characteristics of the pyrolysis products of waste furniture can provide more research directions for the recycling and utilization of these materials. [ABSTRACT FROM AUTHOR]

In this study, wood samples extracted from the Taicang ancient ship, dating back to the Yuan Dynasty, were investigated to study the characteristics of waterlogged archaeological wood. The macroscopic characteristics and microscopic structures were used to identify the wood species. To assess the degree of degradation of the waterlogged archaeological wood, X-ray diffraction (XRD), nanoindentation (NI), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) were used to compare the new and ancient wood samples from the same species. The microscopic structures of the samples were identified as Pinus massoniana. The XRD and nanoindentation results revealed that the crystallinity index of the cellulose decreased from 41.07% to 33.85%, the elastic modulus was reduced by 20.90%, and hardness was reduced by 55.6% compared with the new wood. The FTIR spectra revealed that biological deterioration occurred in the cellulose and hemicellulose, but there was no noticeable change in the lignin content. These results provide helpful information for the conservation and restoration of ancient ships. [ABSTRACT FROM AUTHOR]

This study presents the results of a comprehensive investigation of a wooden rice bucket made in the 1860s. Macroscopy aspects and microscopic structure were conducted to identify the wood species. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) were also adopted to investigate the degradation degree of the rice bucket compared with a new wood sample from the same species. The results of the microscopic identification concluded that the rice bucket was made of Chinese fir (Cunninghamia lanceolata). The XRD pattern indicated that the crystallinity degree of cellulose in the wooden rice bucket decreased to 33.2% from 38.8% (new wood). The FTIR spectra revealed that natural ageing resulted in the degradation of cellulose and hemicellulose, and the change of lignin was not obvious. [ABSTRACT FROM AUTHOR]

This paper investigates the potential of clove (Eugenia caryophyllata) essential oil (C-EO) as a wood protection system for use in cultural heritage conservation. The preventive and curative antifungal efficacy of C-EO was compared to a boron containing wood preservative (Diffusit S) in two laboratory tests on European beech (Fagus sylvatica) and Scots pine sapwood (Pinus sylvestris) mini-blocks. Non-sterile, air-infected wood samples were employed in the first test, while wood samples with active attack, as result of inoculation with three fungal strains isolated from cultural heritage sites, in the second test. Untreated controls and C-EO-treated wood blocks were incubated up to 150 days to monitor and quantify fungal growth. The experimental results showed antifungal efficacy of C-EO to be higher than that of the boron wood preservative at the concentrations used. Concentrations of C-EO 5 % - 10 % in ethyl alcohol prevented mould growth for at least 150 days, while a concentration of 10 % delayed or suppressed active attack by decay fungi. This effect, determined up to 90 days of incubation, was dependant on the type of fungus. [ABSTRACT FROM AUTHOR]

The improvement of wood-plastic composites properties by additives and compatibilizers is a critical issue to produce value-added materials. High-density polyethylene-wood composites have been obtained through compression molding at 140 °C, using two types of additives, namely methyltrioctylammonium bis (trifluoromethylsulfonyl)imide and trihexyltetradecylphosphonium bis (2,4,4-trimethylpentyl) phosphinate room temperature ionic liquids. The ionic liquids improve the interfacial adhesion between the wood and the polymer phases, contributing to an increased stability of the material to water action and to an improved impact resistance and tensile strength in comparison with the reference. Also, the FTIR spectroscopy tests have proven a higher resistance of the ionic liquid-containing composites to accelerated photooxidation. Preliminary screening tests have also proven the antifungal character of the ionic liquids used in this study against brown rot ( Postia placenta). This study opens new insights in the domain of polymeric composite materials, through documenting the possibility of blending new types of chemically distinct materials, difficult to be achieved by traditional functionalization/derivatization routes. [ABSTRACT FROM AUTHOR]

This research paper is related to conservation - restoration of decorated furniture objects with intarsia by highlighting the influence of aesthetic quality of these special surfaces. The effects of natural aging by indoor exposure are presented. Different wood species as well as finishing materials was employed in order to show in time evolution of chromaticity changes of the unfinished and transparently finished wood surfaces. The effect of in time colour modification, after, a total period of 18 month of natural aging exposure was studied. Three wood species were selected ash (Fraxinus excelsior), walnut (Juglans regia) and Sycamore maple (Acer pseudoplatanus) and three type of traditional finishing material (beeswax, linseed oil, shellac). This traditional finishing material was the most used material in furniture manufactured of old objects. The experimental results show that a protective finishing material, resisted to light, has to be used for maintaining the esthetical value of intarsia design. Otherwise the contrast colour between wood species is lost in time and will become null. The data are also useful for current approaches of the intarsia technique to provide data for an adequate choice of finishing technology with traditional products, which will add value to the objects. [ABSTRACT FROM AUTHOR]

A voluntary action is the key for individual benefits in addition to social ones. The voluntary actions for cultural heritage conservation are meant to provide gains for longs terms and to raise public awareness on the importance of conservation-restoration activities. During the past 5 years different volunteering actions for cultural heritage conservation organized by our faculty alone or in cooperation with the ASTRA Museum from Sibiu were finalized with exhibitions and public events. The case study presented in this paper is referring to the conservation-restoration of two long benches with backrest, dating from the first half of XXth century. The benches restored make parts from a group of artefact that was restored in the restoration camps at ASTRA Museum in 2013 and 2014. The particularity of the benches was de finishing layer that imitates the wood texture known as flander technique. This type of finishing is common to the landler community who was deported from Austria to Transylvania at the end of 17th century. The approach of conservations - restorations process was different for the artistic painting parts and needs special and appropriate intervention and investigation. While minimum interventions were making in order to preserve the objects for the future, we want to ensure that the value of less known technique can be well understood by younger generations. [ABSTRACT FROM AUTHOR]

The adhesives compositions for wood gluing have to complied special requirements to be called structural adhesives. Three adhesive compositions based on polycondensation, namely an urea-formaldehyde adhesive, a mixed furan resin and a mixture of these in equal proportions, were tested in terms of their compliance to the requirements imposed for structural adhesives by SR EN 301:2006 and their classification as type I or type II based on their expected performance in service in different specified environmental conditions. Two tests were employed for this purpose: determination of the influence of acid attack on the wood fibres on the transverse tensile strength and the determination of the effects of wood shrinkage on gluing strength. The results shown that: the adhesive composition based on urea formaldehyde resin, included in this research only as a reference, does not comply to the requirements for structural adhesives, the mixed furan resin complies entirely to the requirements for structural adhesives of type I. The adhesive composition based on mixture equal proportion of these resin demonstrated a significantly improved performance compared to the reference urea-formaldehyde adhesive, but could not reach the requirements for the structural adhesives. However, it shown a much better resistance to climatic cyclic aging compared to the UR reference, which clearly demonstrates the positive effect of the mixed furan resin. [ABSTRACT FROM AUTHOR]

The main objective of this paper is the comparative study of some adhesive compositions based on mixed furan resin with furfurylic alcohol of FC-2 URELIT type, compared to a classic urea resin of URELIT R type, using the same addition amount of rye flour or technical lignin of PROTOBIND type, at 2 and 4 hours pressing time. The determination of the quality for such adhesive compositions was achieved through determination of the gluing shearing strength of some beech samples, in dry state, as well as under diverse climatic exposure conditions according to STAS 5114-85. It was established that the gluing shearing strength of all adhesive compositions mostly depends on four influencing factors, namely: type of resin, type of dilution-plastifying material, pressing time and type of applied treatment. Regarding the influence of the resin type, it was shown that the gluing shearing strength for the adhesive compositions based on mixed furan resin with furfurylic alcohol are superior to the ones which use the classic URELIT R type urea resin. Regarding the influence of the dilutionplastifying material, the best results were obtained when instead of the rye flour, a technical lignin of PROTOBIND type was used. Regarding the pressing time, it was found that the gluing shearing strength increases with the pressing duration, the values obtained at 4h pressing time being much higher than at 2h pressing time. Regarding the influence of the applied treatment, it was found that the gluing shearing strength is much higher in case of the dry treatment and the order of decreasing values for the five analysed wet treatments was also established. As an overall conclusion of the performed study, it was found that the use of the adhesive compositions based on mixed furan resin with furfurylic alcohol of FC-2 URELIT type allows the reduction of the specific glue consumption by ca. 45%. [ABSTRACT FROM AUTHOR]

Obiectivul de bază al lucrării constă în studiul comparativ al calităţii unor compoziţii adezive pe bază de răşină furanică mixtă cu alcool furfurilic tip URELIT FC-2 în raport cu o răşină ureică tip URELIT R, folosind adaosuri similare de făinǎ de secarǎ sau lignină tehnică tip PROTOBIND la duratele de presare de 2 ore şi respectiv 4 ore. Stabilirea calităţii acestor compoziţii adezive s-a realizat prin determinarea rezistenţei încleierii la forfecare ale unor epruvete din lemn de fag atât în stare uscată, cât şi supuse în prealabil unor regimuri speciale de tratament conform prevederilor STAS 5114-85. S-a constatat că rezistenţele încleierii la forfecare a compoziţiilor adezive depind în principal de patru factori: tipul de răşină, tipul materialului de diluareplastifiere, durata de presare şi tipul tratamentului aplicat. Referitor la influenţa tipului de răşină, rezultatele arată că rezistenţa încleierii la forfecare a compoziţiilor adezive pe bază de răşină furanică mixtă cu alcool furfurilic sunt mult superioare celor cu răşină ureică clasică tip URELIT R. Referitor la influenţa materialului de diluare-plastifiere, cele mai bune rezultate se obţin atunci când în locul făinii de secară se utilizează o lignină tehnică sulfat tip PROTOBIND. Referitor la influenţa duratei de presare, rezultatele indică tendinţa de creştere a rezistenţei cu durata, valorile obţinute pentru durata de presare de 4 ore fiind mai mari decât cele obţinute la durata de 2 ore. Referitor la tipul tratamentului aplicat, valorile rezistenţei la forfecare a încleierii în cazul tratamentului în stare uscată sunt net superioare celor obţinute în cazul tratamentelor în stare umedă, fiind stabilită totodată şi ordinea de descreştere a valorilor pe cele 5 tipuri de tratamente umede analizate. Ca o concluzie generală a studiului efectuat, se poate afirma că, utilizarea compoziţiilor adezive pe bază de răşină furanică mixtă cu alcool furfurilic permite reducerea consumului specific de adeziv aplicat cu cca. 45%. [ABSTRACT FROM AUTHOR]

The paper presents the results of some own studies performed at laboratory scale, regarding the gluing shearing strength of some adhesive compositions based on mixed furan resin with furfurylic alcohol of FC-2 URELIT type in equal weight proportions with ureic resin of R URELIT type, which are stipulated to be used for solid wood gluing at environmental temperature. As catalyst a constant addition of 5% ammonium chloride and IR hardener was used, both in solid state and aqueous solution with the concentration of about 20%, and respectively, 25%. The gluing shearing strength in dry state and after 24h of water immersion were determined after 4h pressing time at the temperature of 20°C, whilst 2 using the specific pressure of 0.5N/mm² and 2 0.8N/mm². The specific adhesive consumptions achieved were by 32%-46% lower than the ones for adhesive compositions based only on classical urea resin of R URELIT type, which was used as control sample, while the catalyst type and form were varied. Compared to the same reference adhesive composition, the gluing shearing strength of the adhesive compositions based on mixed furan resin with furfurylic alcohol of FC-2 URELIT type, calculated in absolute values at the same specific consumption of dry adhesive, was by 43-88% higher in dry state and by 51-164% higher after 24h of water immersion at 20°C. The obtained results revealed that, in the case of adhesive compositions that contain mixed furan resin with furfurylic alcohol of FC-2 URELIT type, the 2 pressure of 0.5N/mm² leads to higher gluing shearing strengths in dry state, while the pressure of 2 0.8N/mm² leads to higher gluing shearing strengths after 24 hours of water immersion at the temperature of 20°C. In the same context, using solid catalysts leads to higher gluing shearing strengths than the use of catalysts in aqueous solution, ammonium chloride having a more favorable catalytic effect than the IR hardener. [ABSTRACT FROM AUTHOR]

Lucrarea prezintă rezultatele unor cercetări proprii efectuate în fază de laborator privind rezistenţa încleierii la forfecare a unor compoziţii adezive pe bază de răşină furanică mixtă cu alcool furfurilic tip URELIT FC-2 în amestec masic egal cu o răşină ureică clasică tip URELIT R, în condiţiile reticulării la temperatura mediului ambiant. Drept catalizator s-a utilizat un adaos constant de 5% clorură de amoniu, întăritor tip IR, fiecare atât în stare solidă, cât şi sub formă de soluţii apoase cu concentraţiile de 20% şi respectiv 25%. S-a determinat rezistenţa încleierii la forfecare în stare uscată şi după 24 ore imersie în apă rece, în condiţiile unei temperaturi de încleiere de 20°C şi a unei durate de presare de 4ore, la presiunile specifice de 0,5 şi 0,8 N/mm². Consumurile specifice de adeziv rezultate au fost mai reduse cu cca. 32%-46% faţă de cazul compoziţiilor adezive numai pe bază de răşină ureică clasică tip URELIT R, folosită ca probă de referinţă, acestea variind în funcţie de tipul şi forma de utilizare a catalizatorilor. În raport cu aceeaşi compoziţie adezivă martor, rezistenţele încleierilor la forfecare a compoziţiilor adezive conţinând răşină furanică mixtă cu alcool furfurilic tip URELIT FC-2, calculate în valori absolute la acelaşi consum specific de adeziv absolut uscat aplicat, sunt mai mari cu cca 43-88% în stare uscată şi cu 51-164% dupa 24 ore imersie în apă la temperatura de 20°C. Rezultatele obţinute au relevat că, în cazul compoziţiilor adezive care conţin răşină furanică mixtă cu alcool furfurilic tip URELIT FC-2 presiunea de 0,5N/mm² duce la obţinerea unor rezistenţe ale încleierii la forfecare mai mari în stare uscată, iar cea de 0,8N/mm² la rezistenţe mai mari dupa 24 ore imersie în apă la temperatura de 20°C. În acelaşi context, catalizatorii sub formă solidă conduc la obţinerea unor rezistenţe la forfecare mai mari decât în cazul utilizării lor sub formă de soluţii apoase, clorura de amoniu având un efect catalitic mai favorabil decât întăritorul tip IR. [ABSTRACT FROM AUTHOR]

The paper refers to the comparative evaluation of the potential antifungal effect of two essential oils: clove (Eugenia caryophyllata) essential oil and cinnamon (Cinnamomum verum) essential oil, against a brown rot fungus (Postia placenta) and a white rot fungus (Trametes versicolor). The screening test employed in this research demonstrated the biocidal antifungal potential of the two essential oils against both fungi tested. Cinnamon essential S-EO showed biocidal effect against white rot Trametes versicolor from 1% concentration and against brown rot Postia placenta from 10% concentration. Clove essential oil CEO showed biocidal effect against both types of fungi, brown and white rot, from 1% concentration. Both esssential oils tested were more active against the brown rot fungus Postia placenta than the white rot fungus Trametes versicolor. [ABSTRACT FROM AUTHOR]

A fragment from an old beam from a Saxon house in Ghimbav - Brașov, bearing the inscription 1733 J, offered the opportunities to study/investigate degradation and ageing phenomena on old wood elements recovered from constructions by colour measurements and FTIR. The results demonstrated different ageing phenomena from the surface towards the inner parts of the wood. A core of basic principles to be considered in modern design approaches of reinterpretation and reintegration of such elements, based on three fundamental phases has been defined. Adequate active conservation methods allowed stabilisation of the material, preservation of historic information and old patina, while highlighting the special aesthetical features of such elements. [ABSTRACT FROM AUTHOR]

This paper presents the conservation - restoration process of a Cassone from the 17th century, a valuable piece of furniture, classified as thesaurus of Romanian Cultural Heritage. This is part of the George Călinescu collection, belonging currently to the Romanian Academy. George Călinescu (1899-1965) was a Romanian novelist, journalist, literature historian and critic, academician, representing an important peer of Romanian culture. Cassone defines an Italian type of highly decorated large chests, usually commissioned by rich merchants and aristocrats families from Italian culture at the occasion of their daughters' marriage. The restoration process of this object was part of an important restoration project undertaken in 2016 at the ASTRA Centre for Patrimony, the Polychrome Restoration Laboratory, from the ASTRA Museum Sibiu. The complex conservation - restoration of this valuable piece of historic furniture, which was in a precarious state of conservation, required specific scientific investigations and appropriate interventions, which are detailed in the paper. [ABSTRACT FROM AUTHOR]

Tung oil and linseed oil are two representative traditional drying oils wich were commonly employed, for centuries, for wood finishing. Therefore, their study in terms of properties, chemical structure features and alterations by ageing is important for furniture conservation. This paper focusses on some comparative properties of Tung oil and linseed oil as wood finishing materials. For this purpose, test wooden samples of Chinese walnut (Juglans mandshurica Maxim.) were coated with these materials by manual traditional techniques. Solids content of the oils was determined in order to approximate the thickness of the resulting film. The colour change brought about by coating of wood surfaces with these oils was measured in the CIELab system. Furthermore, an accelerated artificial ageing test under the action of temperature (100°C) was performed in order to evaluate and compare the ageing resistance of the two types of oils. Ageing phenomena were investigated by colour measurements and FTIR - ATR spectrometry. Both uncoated and oils coated wood surfaces suffered colour changes observed as darkening and colour shade shifting to red and yellow, but these were obviously more evident for the oil coated samples. The overal colour changes were maximum for the samples finished with linseed oil, while tung oil semmed to be more resistant. FTIR investigations for two types of oils highlighted similarities and differences in their chemical composition, curing and aspects of the thermally induced ageing mechanism. The later proved to be mainly an oxidative degradation process leading to formation of free fatty acids and other carbonyl containing compounds, as suggested by the broader carbonyl (1740 cm-1) and hydroxyl bands (3400 cm-1). [ABSTRACT FROM AUTHOR]

Conservation of cultural heritage relies on scientific investigation of artefacts, a key point being identification of the original materials. In this context, besides wood species identification, investigation of finishing layers is of ultimate importance for old furniture and any other wooden objects with historic, documentary or artistic value. The present paper refers to a series of micro-destructive investigation methods applied for identification of finishing materials, namely: simple in situ and laboratory physical tests, optical microscopy, micro-chemistry and FTIR - ATR analysis. Small samples of finishing layers were taken from four furniture objects belonging to CNM ASTRA Sibiu and were analysed according to the usual procedures of the laboratories from Sibiu and Brasov. The results showed that physical tests and microscopy are useful to get basic information on the samples' morphology and possible classes of coating materials, while micro-chemistry revealed by some successive tests more specific information on the type of finishing materials. FTIR - ATR is a rapid method of identifying the coating materials based on available reference samples or spectra. However, this is not always straightforward and preliminary physical tests of solubility are useful to select the adequate references, while micro-chemistry tests could complete the FTIR result, especially for those components of the finishing layer present in very small amounts (less than 5%), bellow the FTIR sensitivity. Corroboration of microscopy, physical and micro-chemistry tests with FTIR can provide more reliable results in terms of finishes identification and also valuable information for restoration. [ABSTRACT FROM AUTHOR]

Performance of wood preservatives or coatings as surface treatments products is closely connected to different needs and requirements. This paper investigated the protective efficiency of such products, on fir wood exposed outdoors for 7 years, in a modified L-joint test. The evaluation refers to degradation as result of the combined action of the biotic and non-biotic factors, active in use class 3. Two common non-destructive methods were used to evaluate the wood exposed outdoors: visual assessment and microscopic evaluation. Rating of the exposed faces showed that untreated control samples presented the most severe biological degradation and cracking. Surface bioprotection minimised discolouration and was generally a beneficial treatment prior coating. The surface treatments investigated in this paper generally delayed the degradation phenomena but could not provide an efficient protection over a long exposure period. [ABSTRACT FROM AUTHOR]

This paper refers to the second edition (2014) of the summer restoration camp organized by our faculty in cooperation with the ASTRA Museum from Sibiu, as a voluntary action for cultural heritage conservation. A group of 13 (thirteen) volunteers, with different levels of experience and expertise in the field of conservation, from undergraduate students to master and PhD students, alongside researchers and teachers, formed an united and dedicated team involved in this action. During a period of two weeks, this team has assumed the challenge of conserving and restoring three very different objects from the collections of ASTRA Museum: a chair from Săpânţa - Maramureş, a long bench with drawers from Scoreiu Porumbacu and a cart from Brateiu - Sibiu County. Within this paper the three objects are briefly presented, alongside with some general aspects related to their conservation, while a more detailed description and illustration of the initial state and the conservation -- restoration schedule is presented for the chair from Săpânţa. A sequence of operations, including dry ant wet cleaning, active conservation by biocide treatments and consolidation of wood material by impregnation with Paraloid B72, structural consolidation of the object, replacement of missing parts, chromatic integration and finishing with beeswax, were necessary for this purpose. An "exhibition" has been set in the working area where the reception of the restored objects was made by the museum's curators. The action as a whole represented a valuable professional and human experience, an opportunity to get new skills and strengthen cooperation with recognised specialists, while bringing a contribution to the necessary effort for cultural heritage conservation. [ABSTRACT FROM AUTHOR]

Chinese lacquer (urushi) is an ancient natural finishing material obtained from the sap of the lacquer trees (Rhus vernicifera). This has been used for millennia to protect and decorate furniture and various artefacts made of wood or other materials. Lacquered objects are important components of Chinese and world cultural heritage and their conservation imposes a good knowledge and understanding of the material and traditional techniques. This paper presents basic information on the Chinese lacquer as material and lacquering techniques in their historic evolution during different dynasties. The experimental part looked at the physical properties of raw urushi lacquer, respectively aspect, solids content and miscibility with different solvents. A limited compatibility with white spirit as potential thinner was demonstrated. Furthermore, the microstructure of the cured film and characteristic chemical features of raw urushi lacquer as liquid and cured film were investigated. The cured film of raw urushi presents a characteristic microstructural pattern. FTIR spectroscopy revealed a partial oxidation and polymerization following processing by Kuromisation. The further curing accentuated these changes, visible as a decrease of hydroxyl absorptions bands (3400 and 1360cm-1) occurring in parallel with an increase of carbonyl band (1740cm-1). A strong decrease of the absorption band at 1270cm-1, which nearly disappears for the cured film, was also observed. [ABSTRACT FROM AUTHOR]

The paper refers to a comparative laboratory study of some traditional natural adhesives and a modern synthetic adhesive, related to their potential use in furniture restoration for solid wood gluing and veneering. Two types of collagen based adhesives (bone glue and rabbit skin glue) and a commercial PVAc D2 type adhesive were tested to determine their adhesion capacity (gluing strength) and controlled reversibility, as a specific requirement in the conservation field. Beech (Fagus sylvatica) solid wood lamellas were used to obtain standard test samples for determining the shear strength (τf, MPa) of the glued joints. Poplar (Populus tremula) wood samples were veneered on both faces with aesthetic veneers of various wood species important for historic furniture. The potential controlled reversibility of these adhesives was evaluated by three original tests on adhesive films, bonded solid wood and veneered samples. The experimental results showed that the collagen adhesives provide strong (τf values around 13.4MPa) but fully reversible bonds, the bone glue being though easier to reverse under the action of heat and humidity than rabbit glue. For the PVAc adhesive type Novobond D2 employed in this research was determined shear strength of about 16 MPa, but its reversibility was limited. Accordingly, the employment of the commercial PVAc type adhesives in the field of furniture/wood conservation should be avoided or at least limited to very carefully considered special situations. [ABSTRACT FROM AUTHOR]

Holy doors, also named royal doors or beautiful gates, are the central doors of the iconostases in the Eastern Orthodox churches. An iconostasis is a complex wooden screen structure which separates the sanctuary (altar) from the nave of the church. Holy doors, as the whole iconostases, are most often very complex polychrome wood artefacts, with sculptured elements, gilded and painted surfaces. Their high value, residing from liturgical, spiritual, artistic, historic and documentary valences, makes their conservation imperious and challenging at the same time. Understanding of the object and scientific investigations are starting key points for an approach in accordance to the code of good practice and ethics. The paper presents the first steps undertaken in the conservation of a 19th Century Holy door, originated from the old orthodox church in Codlea (Brasov county), presently belonging to the local Museum of Traditions. Active conservation methods to preserve the very frail painting layer, the gilding and the wood substrate, with massive insects attack, were applied. Microscopy, FTIR spectroscopy and XRF were employed to investigate the original technique and materials, to highlight the initial conservation state and also assist the cleaning interventions. [ABSTRACT FROM AUTHOR]