Omkonservering av Vattendränkt Läder Analys och Metodutveckling för Vasaskeppets Läderartefakter

Abstract

In the collections of the Vasa Museum, 100 leather objects have exhibited salt precipitations. The objects, that have previously been impregnated with PEG, have become deteriorated and fragmented due to the precipitations. During a previously conducted study it was established that the precipitations consisted of iron and sulphur. However, it was not established whether they occurred in the leather’s inner structure and no treatment plan was developed. The aim of this study has been to discuss a potential conservation treatment suitable for previously treated, waterlogged leather, which would be achieved through experimental analysis and literature studies. The experimental analysis included XRF analysis, which established the mineral contents of the inner structure, as well as FTIR analysis, which established organic components. The literature studies would culminate in a comparison between the treatments tested on the Vasa ship and other wooden objects from the museum’s collections and the treatments applied on waterlogged archaeological leather. The experimental analysis revealed that contents of both iron and sulphide occurred within the leather, though the organic contents couldn’t be completely determined. The literature studies revealed that chelating agents have been tested extensively on the Vasa ship and her wooden objects as well as on waterlogged leather, though before impregnation. Chelating agents could potentially remove the traces of iron and sulphur, though it was concluded that the treatment would bring unnecessary risks to the Vasa leather. A minimal treatment plan was therefore suggested, in which the leather objects would be stored in stable environmental conditions to prevent new precipitations and surface salt precipitations would be removed mechanically. A future research project was proposed where the effects of chelating agents would be observed on previously treated, waterlogged archaeological leather artefacts.