Stabilisation and Consolidation

Almost all washing and electrolytic conservation treatments leave the artefact in a wet condition. This moisture has to be removed if further corrosion is to be prevented. For small artefacts, drying in an oven is very common, while for large ones such as cannons, hot air blasts or infrared lamps are employed. 

Thermoplastics in the form of a lacquer have poorer mechanical strength than the thermosetting resins but are more easily removed, should this prove necessary. Polyvinyl acetate and polyurethane are good examples of this class of consolidants, particularly on wrought iron artefacts. Many of the copper and copper-based alloys, such as bronzes and brasses recovered from the Mary Rose, were consolidated with a solution of acrylic resin dissolved in toluene (Incralac). 

Waxes are probably the most extensively employed consolidants because of their versatility. The artefact could be immersed in molten wax, which solidifies within the pores of the corrosion layers. Naturally-occurring beeswax is a common example, while microcrystalline waxes are now formulated to meet the requirements of the conservator such as hardness, colour, melting point, etc. The surface of the wax can now be further modified by the application of graphite powder to give an appearance similar to that of a wrought iron finish. 

Pearson, Conservation of Marine Archaeological Objects, Butterworths, London, 1987. 

Metallography of Ancient Objects, Summer School Press, Institute of Archaeology, London, 1987. 

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