THE COMPARISON OF STABILIZATION METHODS FOR COPPER ALLOY ARCHAEOLOGICAL OBJECTS ON THE EXAMPLE OF THE COINS FROM TAURIC CHERSONESOS

Abstract

1. V. Strukova

The paper reviews the main methods of stabilizing copper alloys using the example of the numismatic finds from the excavations of Tauric Chersonesos. In the course of this work, the coins were subdivided into seven groups depending on their preservation level and the methods applied. As a result of the completed work, con­clusions were made on the efficiency of the methods applied. It became obvious that not all copper alloy items require stabilization. The benzotriazole treatment can be used selectively, with adherence to the necessary safety measures and mandatory verification of the result. The deep rinsing method is only effective for objects shallowly affected by active corrosion. The tannin treatment is more effective for items where copper chlo­ride is deposited along the metal grain boundaries. The silver oxide treatment is affordable and effective, but it changes the colour of the object's surface. The Rosenberg method also changes the colour of the surface of the objects. A combination of tannin and silver oxide treatment has shown high efficiency of stabilization and reduction in the rate of corrosion processes. However, this requires closer follow-up observation of the objects.