The post-treatment deterioration of marine
archaeological wood – where to now?

Dublin Core

Title

The post-treatment deterioration of marine
archaeological wood – where to now?

Subject

Session 7
Preservation and conservation of wet archaeological materials and site management

Description

As waterlogged wood is ubiquitous in excavation sites, being used for structures (ships and buildings), tools, personal effects and for decorative artefacts, this material has been the subject of most conservation research and treatment over the past few decades. The development of disfiguring white deposits on treated timbers from the Skuldelev Viking ships from Roskilde Fjord in the late 1970s was initially treated as a minor cosmetic problem. The seriousness of the situation was soon realized when more timbers were affected and the destruction of timber tissue became evident. Similar problems have also been encountered with the Batavia timbers from Western Australia, the Shinan ship in Korea and artefacts from the Mary Rose in England. Problems associated with the presence of iron corrosion products in treated, formerly waterlogged timbers were further highlighted in 2000 with the development of highly acidic regions on some Vasa timbers and associated artefacts. These outbreaks on the Vasa were thought to be related to the inability of the climate control system to keep the relative humidity in the gallery below 60%. These post-treatment developments prompted a significant period of focused research and conservation activities, this time involving multi-faceted analyses and the development of strategies to address a problem that has the potential to affect all waterlogged timbers excavated from anaerobic sites. This paper reviews the current situation regarding the role that iron species play in promoting the formation of acidic species and in catalyzing the oxidation of reduced sulfur species, cellulose and polyethylene glycol and the steps being taken to reduce post-treatment deterioration of formerly waterlogged wood. The implications for future conservation treatments of waterlogged wood are discussed.

Creator

Godfrey, I. M.
Richards, V. L.
Cha, M. Y.

Date

November 2011

Files

Citation


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