AHRC/CDA in partnership with Historic Scotland and the Tank Museum
Quantifying corrosion of historical wrought iron and steel to develop predictive preservation methods and strategies
This Cardiff University based CDA studentship involves research partners Historic Scotland and The Tank Museum . It will quantitatively determine corrosion rates of wrought iron and industrial age steels, then assess the performance of a range of selected coatings applied to their surfaces. The data will be contextualized for heritage by examining how it can be used in evidence based management of ferrous metal heritage, with particular reference to the needs and practices of the project partners. There will be 6 months placement with Historic Scotland and visits to the Tank Museum. Both partners will take an active part in the research, trial its outcomes and offer strong communication routes for dissemination to the sector.
Iron forms a large part of the historical heritage in museums, monuments and engineering and is prone to corrosion which must be controlled or prevented. Many museums contain a wide range of vehicles, machinery and equipment housed outdoors or in uncontrolled sheds and stores, where they are subjected to high humidity and condensation. Within the heritage sector controlling this corrosion is expensive mostly takes the form either of protective coatings such as paints, lacquers and waxes or environmental control of moisture levels that promote iron corrosion. Most data used to support the use of coatings in conservation is qualitative. How well coatings protect heritage iron and for how long is largely unknown and so are the corrosion rates of many uncoated iron alloys. Quantitative data is needed to address both these unknowns and to develop evidence based conservation offering predictive treatment and accurate estimation of corrosion damage.
This research project will quantify the corrosion rates of historic wrought irons from architectural furniture and steels from historic military vehicles. A survey of ferrous alloy composition on vehicles at the Tank Museum will form part of the study to support sample selection. Quantification of corrosion will be precisely recorded by measuring how much oxygen individual iron samples consume within a controlled relative humidity. Results can be used to determine the impact of storage environments on corrosion of heritage iron and steel. The same quantitative method will be applied to assess the performance of historic ferrous metal samples covered with protective coatings currently used within conservation. The results will facilitate direct quantitative comparison both between coatings and to the corrosion of uncoated samples in the same environment. Ultimately, the project will provide the structure and some underpinning data for a management tool to preserve ferrous metals within the Heritage Sector. The aim is also to provide a reproducible test methodology that will allow other researchers to contribute to a data base on by testing new coatings and different ferrous alloys.