Showing papers in "Studies in Conservation in 1983"
84 citations
TL;DR: In this paper, a procedure for extracting dyes from textile samples is described, based on comparison of the visible spectrum with those of known dyes, which can be used to strengthen the identification of the dye.
Abstract: Some of the dyes that may have been used in Anglo-Scandinavian York are listed. Procedures for extracting dyesfrom textile samples are described. Identification of dyes is based on comparison of the visible spectrum withthose of known dyes. Addition of magnesium acetate to a solution in methanol of many of the mordant dyes causes a characteristic change in the absorption spectrum which enhances the sensitivity of the detection, and can be used to strengthen the identification of the dye. Because of spectroscopic interference from staining extracted from the textile along with the dye, yellow dyes cannot be reliably identified without separation of dye from dirt. The extraction procedures described are not, in general, applicable to lichen dyes. Of over 90 Anglo-Scandinavian textile samples investigated, over one half show evidence of having been dyed, and on about onequarter of the samples, madder and indigotin were positively identified. The madder was Rubia tinctorum L. Yellow dyes, and probably...
49 citations
TL;DR: In this paper, the main features, molecular structures and physical and chemical properties of these carbon types, so far as they are relevant to pigment studies, are reviewed in outline and some better-known pigments based on carbon are summarized, with an indication of which form or forms of carbon each contains.
Abstract: A primary classification of carbons is into crystalline and non-crystalline forms. The only crystalline carbon encountered as a pigment is graphite; a secondary classification for non-crystalline forms is into flame carbons (formed in the gas phase), cokes (formed in a liquid or plastic phase), chars (formed entirely in the solid phase) and natural forms such as coal. The main features, molecular structures and physical and chemical properties of these carbon types, so far as they are relevant to pigment studies, are reviewed in outline. Some better-known pigments based on carbon are summarized, with an indication of which form or forms of carbon each contains. X-ray diffraction patterns for graphites, and for examples of the non-crystalline types, are described and discussed. Particle morphology of various carbons and pigments, as elucidated from scanning electron micrographs, is described in some detail, and notes are added on the use of optical microscopy in studying these materials.
48 citations
TL;DR: In this article, the ratio weight:volume has been determined for ironwork from four archaeological sites and it is shown how this ratio can be used to determine the presence or absence of metallic iron in a corroded artifact.
Abstract: The ratio weight:volume has been determined for ironwork from four archaeological sites. It is shown how this ratio can be used to determine the presence or absence of metallic iron in a corroded artifact. Experiments show that totally mineralized ironwork generally contains much less chloride than does ironwork retaining a metallic core. Accelerated corrosion experiments show that totally mineralized ironwork is not subject to a physical deterioration seen on objects retaining a metallic core. Therefore it is suggested that the ratio weight:volume can be used to predict the stability of ironwork following excavation. Costs of storage can be reduced since fewer environmental controls are necessary. Some aqueous chloride extraction methods were examined to determine if the weight:volume ratio influenced their efficiency but results were inconclusive.
44 citations
TL;DR: In this article, the principal alloys discussed are gold-copper, gold-silver and goldcopper-silver, and some problems related to the conservation of gold alloy antiquities are mentioned, together with the difficulty of the preservation of technological evidence.
Abstract: The different ways in which gold alloys can deteriorate are described. The principal alloys discussed are gold-copper, gold-silver and gold-copper-silver. Examples of South American gold alloys from Colombia and Panama are used to illustrate the different types of corrosive attack. Some problems related to the conservation of gold alloy antiquities are mentioned, together with the difficulty of the preservation of technological evidence.
38 citations
TL;DR: Barium copper silicate, BaCuSi4O10, an artificially produced mineral, has been identified on Chinese painted ceramic objects attributed to the Han dynasty (208 Bc-220 AD).
Abstract: Barium copper silicate, BaCuSi4O10, an artificially produced mineral, has been identified on Chinese painted ceramic objects attributed to the Han dynasty (208 Bc–220 AD). The mineral has also been observed as an important component in octagonal sticks probably dating to the Warring States period (475–221 BC) or to the Han dynasty. This man-made mineral has been hitherto unreported as a pigment in the ancient Chinese palette.
35 citations
TL;DR: In this paper, the Sainsbury Centre for Visual Arts used experimental measurements and computer modelling to investigate the system of local humidity control at the Sainbury Centre of Visual Arts, and the results showed that the sorbent's chief function is to buffer seasonal humidity variations.
Abstract: Environmental monitoring data, experimental measurements and computer modelling have been employed to investigate the system of local humidity control at the Sainsbury Centre for Visual Arts. Experiments to determine therate of display case leakage suggested diffusion was the main control for gas transport, and water vapour was transferred with a half-life of 1·75 days. Three parameters, exchange rate constant, half-life and residence time are used to describe gas transfer to and from cases. Equations are provided for calculating the slope of the sorption isotherms of various sorbents in order to assess their effectiveness at desired relatIve humidities. Computer modelling demonstrated that the sorbent's chief function is to buffer seasonal humidity variations; it was shown that a well-sealed case damps out the more rapid diurnal fluctuations. Modelling is also used to illustrate the benefit of minimizing case leakage and increasing the mass of sorbent to extend hygrometric half-time.
29 citations
22 citations
TL;DR: A survey of previous research on the his-tory and composition of niello is given in this article, along with recipes for nierello which are recorded in some mediaeval technological treatises.
Abstract: This paper surveys previous research on the his- tory and composition of niello and discusses recipes for niello which are recorded in some mediaeval technological treatises. Analytical results (by X-ray diffraction and X-ray fluorescence in the scanning electron microscope) are then reported for 18 niello inlays in copper, silver or gold objects from a wide range of cultural periods and geo- graphic areas.
20 citations
TL;DR: In this paper, structural changes during the hardening of silicone films and in testing environments such as SO2, Na2S04, are described, and an attempt is made to clarify the attack mechanism of SO2 on the silicone films.
Abstract: Structural changes during the hardening of silicone films and in testing environments such as SO2, Na2S04, are described. An attempt is made to clarify the attack mechanism of SO2 on the silicone films.Problems directly relevant to conservation practice are discussed, including processes taking place during salt crystallization In porous stone and the effectiveness of destructive tests in SO2 atmosphere and during frost-defrost cycles.
19 citations
TL;DR: In this paper, samples of pigments from a wall-painting of a house of the first Pompeian style (400 Bc-168 BC) found in Pella, Greece, were analyzed by the non-destructive methods of Xray fluorescence and X-ray diffraction, and red pigments were identified as cinnabar and iron oxide pigments (haematite and goethite).
Abstract: Samples of pigments from a wall-painting of a house of the first Pompeian style (400 Bc–168 BC) found in Pella, Greece, were analyzed by the non-destructive methods of X-ray fluorescence and X-ray diffraction. Red pigments were identified as cinnabar and iron oxide pigments (haematite and goethite). Blue was the well-known Egyptian blue and yellow was identified as goethite. A characteristic feature of the wall-painting was the presenceof green earth, i.e. celadonite and glauconite, encountered for the first time in this series of investigations.
TL;DR: In this paper, thermal stress arising from environmental conditions, and structural deformations induced by some recurring stress mechanisms, have been studied for the statue of Marcus Aurelius in Rome.
Abstract: In this experimental work, thermal stress arising from environmental conditions, and structural deformations induced by some recurring stress mechanisms, have been studied for the statue of Marcus Aurelius in Rome. In order to characterize thermal exchange between the monument and the surrounding air, temperature measurements of some significant zones have been recorded with the aid of thermocouples and a thermovision survey of surface temperature distribution was carried out during the course of cooling of the metallic structure and of the stone pedestal. In addition, mechanical stresses have been evaluated by recording pressure waves with an acoustic emission apparatus.
TL;DR: A simple washing procedure has been developed for stabilization of corroding aluminium-copper alloys as mentioned in this paper, using an ammonia-ammonium sulphate buffer at pH 9·6 in aerated deionized water.
Abstract: A simple washing procedure has been developed for stabilization of corroding aluminium-copper alloys. The use of an ammonia-ammonium sulphate buffer at pH 9·6 in aerated deionized water effectively removes cemented copper metal and copper corrosion products from the surface of the object whilst also removing aggressive chlonde ions. This treatment has been used to stabilize a Duralumin sea-plane float which was actively corroding after 46 years' exposure to a marine environment.
TL;DR: In this paper, the main principles of the application of epoxy resins for the consolidation of porous inorganic materials are summarized, and the most important requirements for the attainment of sufficiently deep penetration are the low molecular weight of resin and hardener, a suitable type and amount of solvent, an effective impregnation method and the prevention of reverse migration.
Abstract: This paper summarizes the main principles of the application of epoxy resins for the consolidation of porous inorganic materials. The most Important requirements for the attainment of sufficiently deep penetration are the low molecular weight of resin and hardener, a suitable type and amount of solvent, an effective impregnation method and the prevention of reverse migration.
TL;DR: In this paper, textiles dyed with turmeric, madder and indigo were exposed to incandescent, fluorescent and tungsten halogen lamps, with infrared and/or ultraviolet filters.
Abstract: Textiles dyed with turmeric, madder and indigo were exposed to incandescent, fluorescent and tungsten halogen lamps, unfiltered and with infrared and/or ultraviolet filters. Color change was measured by the K/S value function after 100, 200, 300 and 400 hours of light exposure. The filtered lamp systems caused significantly less fading than did the unfiltered systems. In general, samples dyed with indigo and turmeric exhibited greater color change than did the samples dyed with madder. Quartz (tungsten halogen) lamp/filter systems caused the least overall color change but exhibited the most sporadic fading curves, and after 400 hours of exposure had caused more color change on indigo- and madder-dyed samples than fluorescent lamp/filter systems.
TL;DR: In this paper, the distribution of polyethylene glycols in wood can be demonstrated even more exactly, even from very small samples, by adopting a print-off technique onto damp filter paper.
Abstract: Polyethylene glycols (PEG) can be detected in wood by their in situ formation of coloured complex compounds. Solutions of potassium bismuth iodide/barium chloride and of bromine/potassium iodide are suitable for sprayingdirectly onto wood, and may even be used on dark-coloured wood by mixing chalk powder into the reagent. By adopting a print-off technique onto damp filter paper, the distribution of PEG in wood can be demonstrated even more exactly, even from very small samples. Print-offs are developed into differentiated coloured pictures withsolutions of potassium bismuth iodide/barium chloride, iodine/potassium iodide or ammonium cobalt (II) thiocyanate.
TL;DR: In this paper, the presence of lime mortars containing varying amounts of an inert fraction such as dolomite, quartz, microcline, sanidine, diopside, analcime and augite was found.
Abstract: Samples from the external facade, internal pillars, wall and floor mosaics of the Cathedral of Salerno and mosaic samples from the Cathedral Museum were examined by X-ray diffraction, thermo-differential analysis and by thermo-gravimetric analysis. They were shown to be lime mortars containing varying amounts of an inert fraction such as dolomite, quartz, microcline, sanidine, diopside, analcime and augite. The predominant binder was calcite deriving from Ca(OH)2 The existence of relicts of Ca(OH)2 and Mg(OH)2 of low crystallinity in some samples is discussed.
TL;DR: In this article, the impregnation of wood by two acrylic monomers, methylmethacrylate and butylmethACrylate, and their subsequent polymerization in wood samples initiated chemically and by gammaradiation was examined.
Abstract: This study considers the impregnation of wood by two acrylic monomers, methylmethacrylate and butylmethacrylate, and examines their subsequent polymerization in wood samples initiated chemically and by gammaradiation. The results of the polymerization were assessed on the basis of the resultant polymer content of the wood, and it was found that polymerization initiated by gammaradiation was more effective. The influence of the consolidation by monomer polymerization upon the properties of the wood (hygroscopicity, water absorption, swelling andcompression strength alorig the fibres) was found to depend on the polymer content of the wood, on the polymercomposition and on the type and structure of the wood. Copolymerization of methylmethacrylate and butylmethacrylate has no benefit on the properties of the wood.
TL;DR: The object of the treatment is to remove the papyri without loss of text while maintaining the visual and aesthetic appearance of the original cartonnage.
Abstract: The removal of papyri from cartonnage (Egyptian mummy cases) is accomplished by facing the object with a tissue coated with pressure-sensitive adhesive, after which the gesso on the inside of the object is removed by means of an enzyme solution. After the removal of the layers of papyrus, the object is backed with Japanese tissue and the facing layer is removed. The object of the treatment is to remove the papyri without loss of text while maintaining the visual and aesthetic appearance of the original cartonnage.
TL;DR: In this paper, the properties of naturally and artificially aged linen fabrics were compared in order to develop a model degraded linen suitable for evaluating the potential of several deacidification treatments, and an evaluation of methods of application concluded that immersion application of aqueous agents and spray application of nonaqueous agents provided better protection during accelerated aging.
Abstract: The properties of naturally and artificially aged linen fabrics were compared in order to develop a model degraded linen suitable for evaluating the potential of several deacidification treatments. Application of deacidification agents and procedures successful in paper conservation reduced the rate of deterioration of artificially degraded linen during accelerated aging. An evaluation of methods of application concluded that Immersion application of aqueous agents and spray application of nonaqueous agents provided better protection during accelerated aging. In addition, washing with deionized water offered no benefit over untreated degraded linen fabric on the basis of accelerated aging tests.
TL;DR: The Lascaux cave is a complex living environment, continually subject to various physical, hydrogeological, chemical and biological phenomena as discussed by the authors, and the area is also subjected, with a certain delay, to external influences transmitted through the rock, water and air.
Abstract: The Lascaux cave, like any other, is a complex living environment, continually subject to various physical, hydrogeological, chemical and biological phenomena. The area is also subjected, with a certain delay, to external influences transmitted through the rock, water and air. Cave art experiences exchanges between the rock and the ambient air of a thermal, hydrous, chemical and biochemical nature. Our studies have enabled us to isolatethe cave within its natural surroundings and have consolidated the fragile equilibrium re-established after the many alterations which the cave has undergone since its discovery in 1940. Ideal conservation conditions areobtained through the efficient functioning and maintenance of mechanical installations which control the thermal conditions of the cave by means of heat-exchangers, a weak concentration of carbon dioxide in the atmosphere maintained by continuous pumping in the Puits du Sorcier and the elimination of seepage water which is collected in a sump and led...
TL;DR: This technique can be used for mosaics of any size, and enables large mosaics to be broken down into sections which are more easily handlable, which facilitates the moving, storage and display of mosaics within a museum.
Abstract: A modification of an existing technique for the lightweight backing of mosaics has been developed. The technique can be used for mosaics of any size, and enables large mosaics to be broken down into sections which are more easily handlable. This facilitates the moving, storage and display of mosaics within a museum, since the mosaic can be mounted either horizontally or vertically on a suitable frame. This method was successfully applied to a mosaic which had been mounted in a traditional manner on a plaster backing many years ago.
TL;DR: Cobalt salts are capable of changing colour as the RH fluctuates and this property can be utilized to manufacture RH indicating cards as mentioned in this paper. But their accuracy was not comparable to the recording thermohygrographs tested.
Abstract: Cobalt salts are capable of changing colour as the RH fluctuates and this property can be utilized to manufacture RH indicating cards. Three commercially available cards have been tested and their accuracy found to be similar to the recording thermohygrographs tested.
TL;DR: In this article, the functional relationships between psychrometric and barometric observations and commonly encountered atmospheric humidity parameters were derived for the practical application of the material, using a programmable pocket calculator.
Abstract: Derivations are given for the functional relationships between psychrometric and barometric observations, and the commonly encountered atmospheric humidity parameters. The use of a programmable pocket calculator is recommended for the practical application of the material.
TL;DR: The Canadian Conservation Institute (CCI) operated five mobile conservation laboratories to provide basic assistance to museums, galleries and other cultural institutions across Canada as discussed by the authors, with the purpose, operational needs and outfitting of the laboratories described, as well as examples of kinds of help they are able to provide.
Abstract: During the past three summers, the Canadian Conservation Institute operated five mobile conservation laboratories to provide basic assistance to museums, galleries and other cultural institutions across Canada. The purpose, operational needs and outfitting of the laboratories are described, as well as examples of kinds of help they are able to provide. An inventory of the material and equipment carried by the mobile laboratory is given