• Journal of Conservation Science
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• v.36 no.2
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• pp.103-111
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• 2020

To compare the cleaning effect of solvents such as water and ethanol used to clean lacquer relics, the components extracted with various solvents were analyzed. A freshly dried lacquer sample and a lacquer sample exposed to ultraviolet radiation for 24 days were treated with water, ethanol, acetone, and hexane, and the dissolved material was detected by pyrolysis-gas chromatography-mass spectrometry. The amount extracted was significantly higher in acetone and ethanol than in hexane, a nonpolar solvent. Water, a highly polar solvent, was relatively efficient for extracting low-molecular-weight materials. After experiencing 24 days of ultraviolet radiation, the lacquer exhibited a significant increase of extracted materials compared with the nonexposed one. This may be due to the degradation of the urushiol chain in the form of polymers, resulting in the formation of low-molecular-weight polar substances, including dicarboxylic acids. In addition to the deterioration status of lacquer relics, such solvent extraction properties will be a crucial consideration in selecting the appropriate cleaning solvent.

• Conservation Science in Museum
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• v.8
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• pp.41-47
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• 2007

The wooden lacquer wares, which had excavated from the water reservoir in the Isong Sansung Fortress, were applied with vacuum freeze drying method and treated, after they had been substituted with tbutanol, and treated with PEG-pretreatment. The manufacturing technique, which had not been investigated in the past, was examined through the investigation of the wood and the lacquer used for wooden lacquer wares, and the pieces of the lacquer wares, which had been stored for a long time, were restored for the exhibition and conservation. As the result, the wooden lacquer wares were manufactured, using black alder belonging to the group of Alnus, and the lacquer was painted on the bottom-layer by mixing the powdered soil and lacquer, and it was confirmed that the lacquer mixed with the black pigment and the pure lacquer had been painted alternatively over 2 times, and that the wooden lacquer ware had been manufactured through total 5 times of being painted.

• Conservation Science in Museum
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• v.12
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• pp.47-52
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• 2011

The authors did conservation treatment of wooden objects excavated from Isong Sanung Fortress upon request of the Museum of Hanyang University. The authors investigated types of the trees prior to conservation treatment to find out 1 Pinus spp. and 11 Querus spp. The authors investigated paint coating of 1 wooden ware to find out No.4 of the exterior and No.3 of the interior and about 100㎛ thickness of the lacquer layer. The. conservation treatment was done to immerse wooden ware into high molecular PEG#3,350 in water solution (10 ~ 45%) and to give physical strength and to do vacuum freeze drying.

• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.96-104
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• 2008

In this study, the observation of test pieces with an optical microscope was carried out after fabricating 4 groups of standard lacquer, in order to inquire into the ancient lacquering techniques. Group I had transparent reddish brown color, and the part of layer was indefinite, and the layer polished was easily distinguished. Group II had mostly transparent yellowish brown color, and it was possibility distinguished the layers when they were varnished with mixed lacquer after prime coating, and when they were varnished with lacquer as the prime coating. Group III set up membrane in the hardening process of the lacquer, and the lacquer and the unsaturated fatty acid of internal part was dried, so the top layer and the lacquer layer were separated and observed. Group IV: When the lacquer coat film of Group IV test pieces were observed in polarized light, the ferrous components were seen as the black and red color were mixed, and the silica crystals of silty soil were distinguished by reflection of lights. And the colors were distinguished as the lacquer layer of ruddle had red color, and the mixed lacquer of reddish lacquer and ruddle had the deep red color at the top and the bottom, but the middle part had the bright red color.

• Conservation Science in Museum
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• v.7
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• pp.53-62
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• 2006

The wooden armor frame and various lacquerware artifacts excavated from the low swamp remains in Imdang, Gyeongsan have very weak material and lacquer coating; in case they are exposed in the air, they are likely to be shrunken and deformed immediately. The wooden armor frame has large size and it might be dissolved during freeze-drying. The lacquer coating of lacquerware blocks the penetration of chemicals and it is very likely to swell or peel off during the treatment. Therefore, to prevent the dissolution during vacuum freeze-drying, the wooden armor frame was replaced with t-butanol and impregnated in t-butanol solution with PEG#3, 350 43%, and lacquerware was impregnated in PEG#3, 350 40% solution at room temperature and freeze-dried. According to the analysis of the lacquer fragment from the lacquerware, the lid and the mounted cup was pasted with the mixture of lacquer and black pigment (soot) on the base layer after the first coating and pasted two or three times more with natural lacquer; the red lacquered wooden cup was pasted with the mixture of lacquer and black pigment on the base layer and pasted once on the middle layer. The top lacquer (red) was pasted with the mixture of iron oxide(Fe₂O₃).

• Journal of Conservation Science
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• v.34 no.5
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• pp.369-377
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• 2018

In order to examine the constituents and weathered state of a lacquer specimen, analysis of the organic materials was conducted using py/GC/MS(pyrolysis-gas chromatography-mass spectrometry). The samples were obtained from the lacquered wooden sheath of a long ring-pommel sword excavated in the Imdang No.1 ancient tomb constructed around the Proto-Three Kingdoms period. In direct py/GC/MS, the sample and the dried Asian lacquer showed similar chromatograms, while the characteristic compounds of Asian lacquer such as 1,2-dimethoxy-3-pentadecylbenzene were observed in THM(thermally assisted hydrolysis and methylation)-py/GC/MS. In addition, compounds like dimethyl nonanedioate, which presumably originated from drying oil, were also detected. Furthermore, the detection of oxidized catechols in considerable amount indicated that the degradation of lacquer is estimated to result from the oxidation of urushiol. Therefore, it is suggested that the lacquered wooden sheath was prepared using Asian lacquer and drying oil, and that the lacquer layer was considerably oxidized over the long burial time.

• Conservation Science in Museum
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• v.11
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• pp.43-48
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• 2010

Excavated lacquer wares can be divided into waterlogged lacquer wares supersatuated with moisture and dry lacquer wares with little moisture. This conservation was done with dry damaged lacquer wares excavated from Daho-ri. Lacquer ware artifacts with lacquer fragments and no surface material remaining were processed using the three following methods. The three methods are reinforcing while sustaining three-dimensional form; reinforcing with earth after cleansing so that fragments are revealed due to weak lacquer fragments; and reinforcing the whole lacquer ware or parts by connecting and supporting missing parts with rayon paper, an artificial fiber paper, if the form cannot be sustained only with lacquer fragments.

• 보존과학연구
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• s.32
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• pp.37-52
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• 2011

This study investigates the hardening characteristics of the mixture lacquer and glue at room temperature. Diverse samples were made from manufacturing of glue to the adding ratio in sap of the lacquer tree. After the examination of moisture content of samples, it has been seen that there is no relation with glue's kinds or adding ratio, but only with contain level of moisture. The samples made with film shape in order to examine the drying time. Samples with isinglass needed for over three days and had smooth surface. However, samples mixed with animal glue dried within a day and had ripples on the surface because of fast drying rate. In addition, the samples with isinglass had slow change of colour in early step of drying and no colour difference after completely drying although it had significant changes to black oxide as soon as contact with air. In structural analysis with FT-IR showed that the carbonyl bond increased in the samples of mixed with glue, compared to raw lacquer and treated lacquer.

• Conservation Science in Museum
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• v.12
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• pp.89-92
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• 2011

Wooden object lacquerware and grass made object excavated were discovered in water. The object can be dry gradually for a long time when it is not kept at water evaporation. Wooden area of wet lacquerware wet organic materials mmersed kept lacquer only on the exterior after being decayed, and most of grass made object were adhered to the earth. In this study, the author preserved lacquerware and grass made equipment at Dahori Changwon that were relics in the Iron Age by using bees wax, rayon pper and layering technique. And, the author could remove ware from the earth to conserve lacquer and grass made object.

• Conservation Science in Museum
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• v.10
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• pp.43-61
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• 2009

The Buyeo National Museum was requested conservation treatment for wooden objects excavated from three Baekje archeological sites: Neungsan-ri, Ssangbuk-ri, and Gungnamji Pond. Prior to conservation treatment, analysis was conducted to identify the species used. The results of the analysis revealed wood from diverse species of trees including Hard pine, Cryptomeria japonica D. Don, Zelkova serrata Makino, Quercus spp., Platycarya strobilaceae S. et Z., Castanea spp., Torreya nucifera S. et Z., Taxus cuspidata S. et Z., and Salix spp. A high percentage of the objects were made of Cryptomeria japonica D. Don., a species native to Japan, which indicates that exchange with Japan was active at that time. Among the wooden objects, we analyzed lacquer fragments from six pieces of lacquerware, and the characteristics of the lacquer fragments were peculiar to specific artifacts. Most of the fragments were thicker than 100 ㎛. Pure lacquer and mixed black pigment were used. Infrared spectroscopy of the lacquered wooden fragments revealed that they had a very similar absorption band as refined lacquer, confirming that they were painted with lacquer. For their conservation, we immersed the objects in a high molecular weight aqueous solution of PEG#3,350 (10% → 50%) to strengthen them before vacuum freeze-drying.