Műtárgyvédelem 22., 1993 (Magyar Nemzeti Múzeum)
Restaurálás - Konzerválás - Morgós András - Hervainé Nagy Judit: Nagy sótartalmú mállott, festett kerámiák restaurálása : sók szerepe a kerámia károsodásában; mállott kerámiák szilárdítása kovasav-észterekkel
CONSERVATION OF DETERIORATED PAINTED CERAMICS HAVING HIGH SALT CONTENT (The role of salts in the deterioration of ceramics; The consolidation of crumbling ceramics using silicic acid esthers) Abstracts: During the conservation of high-level salt-containing ceramics, the salt must be removed from the structure of the ceramic to prevent the further deterioration of the ceramic. The ceramics containing high salt content are usually badly deteriorated which is why they required reinforcement. The removal of salt and the consolidation are the two main conservation processes used. The article describes these two procedures in details. If the ceramics are painted, this makes the conservation more difficult. The removal of salt is made by dissolving in water. It can be made theoretically before consolidation as well. But in the case of painted ceramics, the practice shows that because of the frequent loosing of the paint layers and the flaking of the ceramic surface, firstly the consolidation and fixing must be done, and later on the desalination. The article describes the restoration of two Coptic, painted ceramic coffin- lid fragments, of high salt-content. First the consolidation of the ceramics was done using tet- raethoxy-silane. This material doesn’t seal the pores of the ceramics so they remain open (permeable) to w'atcr used for desalination. The next step was to fix the paint- layer and the flaked superficial ceramic layers. The pigments were fixed to each other using 5% Paraloid B72 in toluene and the flaking of the ceramic surface was fixed using 15% Paraloid B72 in toluene. Thereafter the painted surface was treated with 15% PVB- (polyvinylbuthirate) in alcohol and stuck with Japanese-paper. The desalination was carried out by extraction using distilled water, with changing of the water- bath from time-to-time. The desalination was continued till the sample taken out from the bath showed a negative silver-nitrate reaction. After the desalination the ceramic was dried out very slowly under controlled conditions. After drying, the removal of the Japanese-paper fixing was carried out using alcohol. During this process, the holes under the paint layers, caused by the removing of the salt crystals were fixed using 15% Paraloid B72-toluene solution. In such cases the removal of the paper occured after the drying of the Paraloid. The complete removal of the Japanese-paper, the rest of the superficial laminations and deep cracks were injected with the same solution. If it was necessary, the fixing to the surface of the lamination was carried out by ironing using silicone-paper isolation layer. Finally the superfluous Paraloid was removed using methyl-ethyl-keton solvent. Szerző cime/Author’s address: Morgós András Műtárgyvédelmi Főosztályvezető/Head of Conservation Department Magyar Nemzeti Múzeum H-1087 Budapest, Könyves K. krt. 40. 1450 Budapest 9. Pf. 124. 60
