ASSESSMENT OF EDTA AS A CLEANING REAGENT FOR STAINED GLASS WEATHERING PRODUCTS (ABSTRACT)
M. Hood*, M. Cole*, D. Littlejohn*, and N. H. Tennent***Department of Pure and Applied Chemistry, 295 Cathedral Street, Univeristy of Strathclyde, Glasgow, G1 1XL, Scotland
**Central Research Laboratory for Objects of Art and Science, Gabriel Metsustraat 8, 1071 EA Amsterdam, The Netherlands
The effect of EDTA on stained glass has been examined using flame atomic absorption spectrometry (FAAS) and inductively coupled plasma-optical emission spectrometry with charge coupled device detection (ICP-OES-CCD). The removal of calcium, potassium, manganese, and copper from glasses designed to simulate medieval stained glass has been assessed to investigate the effect of (a) EDTA concentration and (b) the pH of the EDTA cleaning solution. The extent of removal of the constituent elements appears to be more dependent on the pH than on the concentratoin of EDTA; eg. the leaching of calcium is greater at pH 7.5 than at pH 6.5. The resultant damage to the glass surfaces has been studied by scanning electron microscopy. In complementary experiments the efficacy of EDTA as a cleaning reagent has been assessed through its efficiency at dissolving a typical weathering product (CaSO4). Again, the parameters of interest were the EDTA concentration and the pH of the solution. The aim of the study is to identify conditions that are effective in removing weathering products, but with minimal damage to its glass surface.
The methods, techniques, and conclusions found in individual papers are the work and responsibility of the author of the paper, and should in no way be thought to represent the opinion or endorsement of either the Journal of Conservation & Museum Studies, the Institute of Archaeology, or University College London. No liability or contract is accepted or implied by the publication of these data.
Copyright © M. Hood, M. Cole, D. Littlejohn, and N. H. Tennent, 1996. All rights reserved.