Archaeological conservation is necessary to properly treat, stabilize and preserve human-made objects or artifacts recovered from underwater archaeological sites. Waterlogged artifacts that are not subjected to physical and chemical treatment in the laboratory usually face rapid deterioration and often utter destruction when exposed to air for prolonged periods. The Lighthouse Archaeological Maritime Program (LAMP) employs a professional archaeological conservator and maintains several indoor and outdoor laboratory spaces for the treatment of artifacts composed of a variety of materials (wood, metal, leather, textile, ceramic, stone, etc). Artifacts treated in LAMP's conservation laboratories range from small items such as coins and nails to large objects including a 2000 lb cannon, a 14-ft long copper-sheathed wooden rudder and a 20-ft long dugout canoe.
The conservation of artifacts is a vital part of any maritime archaeological research program. Artifacts, or human-made objects, submerged in a marine or aquatic environment undergo significant changes as time goes by. When removed from a shipwreck site and exposed to air for the first time in possibly centuries, such artifacts are in danger of rapid deterioration unless they are immediately stabilized and treated by a specialist known as a conservator. Left untreated, an iron object such as a sword blade will soon begin to oxidize and eventually crumble to dust, similarly, a wooden object such as a tool handle will shrink, shrivel and possibly fall to pieces. This damage can be postponed by keeping the artifact in question wet, but eventually it must be subjected to proper chemical and/or physical treatment in the laboratory.
The conservator determines the specific treatment for each artifact, which varies according to the material from which the artifact is made. Stone objects, such as ballast or gunflints, often need little more than fresh water soaking and physical cleaning, while iron objects such as cannon and anchors must be subjected to a constant electrical current and chemical bath in a process which might last for five years or more. Conservators also carefully record the objects in their care through drawing, measurements and photography at each stage of treatment. Sometimes exceptionally complex objects, such as a heavily concreted wooden box of flintlock pistols, might be recovered intact by field archaeologists and then "excavated" by conservators in the controlled conditions of the laboratory. Often, chemical or x-ray analyses will reveal secrets that could not be discerned in the field. Because of this, conservators often learn as much or more about a shipwreck from their laboratory work as do archaeologists working on the site itself.
Since LAMP archaeologists regularly recover artifacts from shipwrecks or other underwater sites in order to learn about the past, we maintain a conservation laboratory overseen by our full-time conservator, Kathleen McCormick. Smaller artifacts can be treated in the laboratory located within the LAMP headquarters on the St. Augustine Lighthouse grounds. We also have an outdoor conservation facility which is used to treat larger artifacts such as cannon and ship timbers.
Explore the links below to learn more about archaeological conservation and ongoing LAMP conservation projects:
- Conservation Workshop
- Conservation Reports & Artifact Studies
- Sucrose Treatment of Waterlogged Wood
- Browse the definitive Archaeological Conservation Manual at Texas A&M’s Nautical Archaeology Program
All text and images, unless otherwise noted, are copyright Lighthouse Archaeological Maritime Program, Inc. We extend permission to scholars, students, and other interested members of the public to use images and to quote from text for non-commercial educational or research purposes, provided LAMP is acknowledged and credited. If there are any questions regarding the use of LAMP’s work, please inquire at LAMP@staugustinelighthouse.org.