Conservation and restoration of shipwreck artifacts

The conservation and restoration of shipwreck artifacts is the act of caring for cultural heritage that has been part of a shipwreck and have often been underwater for a great length of time. Without conservation most artifacts will perish and important historic data will be lost. In archaeological terms, it is usually the responsibility of archeologist and conservator to see that material recovered from a shipwreck is properly cared for. The conservation phase is often time consuming and expensive, sometimes costing more than the original excavation. One of the most important considerations when planning or implementing any action that will result in the recovery of material from a shipwreck of any marine archaeological site.

Artifacts recovered from the sea, a saltwater environment, are often preserved but fragile and friable by nature. Once the artifacts are brought to surface, and exposed to air and light, the artifacts will degrade rapidly. Artifacts that are not conserved in timely manner will deteriorate at a rapid rate. Organic material, such as wood, leather, textiles, etc.,. if allowed to dry without conservation treatment, can in a matter of hours deteriorate and crumble. Other materials such as bone, glass, pottery, and similar materials, if not conserved, will slowly devitrify and in extreme cases will degenerate to a pile of slivers. Conservation must be part of any archaeological project, especially for underwater archeological sites. Artifacts found in salt water has the greatest challenge to a conservator. Artifacts from a saltwater environment are saturated with salt that must be removed when the artifacts are recovered.

Approximately 70% of bone and ivory are made up of an inorganic lattice composed of calcium phosphate and various carbonates and fluorides. The organic tissue of both is ossein and it constitutes at least 30%. It's difficult to distinguish them apart, unless examined microscopically. Both bone and ivory are easily warped by heat and moisture, and deteriorates by prolonged exposure of water.

Bone and ivory being at a saltwater environment will absorb soluble salts and crystallizes when removed from water as the object drys. The salt crystallization will make the surface flake and can destroy the object. In some cases when bone and ivory suffer ossein loss due to hydrolysis, it leaves the calcareous substance; the calcareous substance can cause the materials to fossilise and once organic content is lost resulting in crystallisation, quartz can be formed. The soluble salt must be removed to preserve and stabilize the object when removed from the marine environment. Artifacts of these type of material is recommended to remove all the soluble salts with the use of water.

...
Wikipedia