Development of an Electrochemical Method for quantitative assessment of Organic Coatings used in Conservation of Archaeological Objects

摘要

Protection of cultural heritage objects is of major importance. Among historical and cultural objects related to boatbuilding, sailing, military science, maritime education are stored and displayed, many of them are made from metal. Although in some cases the visible changes on the metal are non-reversible in character, it is the job of the conservator to try to establish as closely as possible the original appearance. In order to prevent the objects from any further degradation after the-conservation process, different approaches are used including application of coatings, wax, paraffin wax and/or addition of different inhibitors. In case of reapplication of the coating conservators traditionally decide when it is necessary based on visible changes (corrosion signs). This is qualitative and is really "too late". Also there is no way currently of assessing quickly candidate coatings and of recommending the appropriate thickness that should be used to achieve adequate protection. Therefore there is a great need to find a method that will allow assessment of the performance of the coating in a relatively short time and efficient way. Electrochemical techniques such as measurement of DC resistance, Electrochemical Impedance Spectroscopy or Electrochemical Noise Measurement offer a way of achieving this. Each produces a number which is a measure of the ability of the particular coating/inhibitor to protect effectively. In this paper the authors look at four wax coatings used to protect metal objects from particular shipwrecks found in Baltic area Results are presented which rank these coatings on steel and copper using DC resistance method. It is anticipated that this work will lead on to become one potential strand of a new development plan for better maintenance of archaeological objects.