Knowledge of the process for conserving and/or preserving metal artifacts, coins or tombstones is very different from cleaning and preserving tombstones made out of stone.
First of all is the fact there are so many different combinations or alloys utilized in the making of an artifact, coin or tombstone.
Secondly and most importantly is to keep in mind whatever is attacking the metal object has been doing this over an extended period of time. With this in mind, stopping and reversing the process needs to be done at a very patient rate.
Metal artifacts recovered from a variety of archeological sites can have all kinds of negative processes working to destroy the object. For instance, any type of metal artifact recovered from a salt water environment such as the Gulf of Mexico has been going through changes ever since it entered the water.
Many readers may remember the excavation work carried out several years ago in the middle of Matagorda Bay. The remains of one of La Salle’s ships, The Belle, was discovered utilizing a remote sensing device dragged behind a boat.