Nicola Emmerson has co-published a scientific paper on corrosion rates of various wrought iron samples when coated with 5 different preparations
We cannot publish anything but the abstract, but she has made her email address available and if you want to question her about her findings, you can. The abstract, which raises some of the issues NHIG was founded to solve, is below:
Emmerson, N. J. and Watkinson, D. E. 2016. Surface preparation of historic wrought iron: evidencing the requirement for standardisation Materials and Corrosion 67 (2), 176 – 189
The conservation of heritage wrought iron relies on corrosion prevention by preparation of surfaces and application of protective coatings. In contrast to industrial and engineering treatment of modern steel, conservation practice is not regulated by accepted national and international standards or underpinned by empirical evidence.
This paper presents the results of oxygen consumption rate testing (as proxy corrosion rate) of historic wrought iron samples prepared by five commonly applied surface preparation methods and subjected to high humidity environments, with outcomes assessed by use of international standards employed in industrial contexts.
Results indicate that choice of surface preparation method has a direct influence on corrosion rate of the uncoated wrought iron, which impacts on performance of the protective coatings that may ultimately determine survival or loss of our rich wrought iron heritage.
By implication, more extensive empirical evidence is required to underpin and develop heritage standards for treatment of wrought iron which encompass specifics of the historic material, heritage context and the ethics of conservation practice. The introduction of such standards is called for in order to bring treatment of historic ironwork in line with highly regulated engineering and industrial practices.