Every shipwreck is like a time capsule, and the artifacts they contain offer a unique vision of the daily lives of the people on board every ship. But before these objects can be studied or displayed in a museum they have to be treated to ensure their preservation for the future.
Conservation is a very important part of an underwater archaeology excavation because the materials recovered from the sea are often well preserved but extremely fragile and, if left untreated, will deteriorate at a very fast rate. The most important thing after the materials extraction is to maintain them in similar conditions to those of the underwater environment; this is why the artifacts are kept in salt water until their arrival to the conservation laboratory.
The typology and characteristics of the artifacts recovered form a shipwreck vary depending on the type of ship that they come from. In the case of naval ships, such as Punta Restelos or the Bayonaisse,we find weapons and ammunition like musket bullets, and objects used in daily life made of cheap materials such as the pewter used for tableware; on the other hand, there is the case of the steamerGreat Liverpool, a passenger steamer where lots of luxury objects including silver cutlery, jewels, and chess pieces were recovered.
The conservation treatments applied vary depending on the material and condition of the artifact. Before any direct intervention on the materials, the soluble salts present in the sea water must be removed; this is done by gradually adding tap water, which is then substituted by deionized water. After salt removal, the condition of the objects is documented by photography and a detailed description. The pieces are then classified by material and condition to determine the most suitable treatment for each one.
By: Victoria Folgueira
Finisterre Project Team.