2025 Poster Session

Abstract

coins are the mirror of any civilization, with its historical, economic, and political information, so it must be restored and cleaned to read the inscriptions and writings on it. Lead material is made of coins are toxic and very sensitive materials, so when restored, it must be made with great care and at the lowest intervention because the increase in restoration work at the permitted limit can lead to its distraction, given that it is a very soft material.

Several scientific methods have been used in documentation, examination and analysis, such as: photography with a modern high -quality camera and a microscopic examination to document the aspects of damage such as: corrosion products that appear white and yellow also  analyzed with Portable X-ray fluorescence spectroscopy (p-XRF) which was determined the metal composition, which turned out to be mainly of lead, copper, iron elements and appearance Elements of corrosion products as: sulfur and chlorine.

After that, the restoration starts with mechanical cleaning by using the wooden stick, ultrasonic pen, and Bass, as the chemical cleaning was used by ethanol, Acetone, Hexametaphosphate and citric acid at a concentration of 3%, which gave an excellent result in removing corrosion products without affecting the patina and mineral metal. Finally, the protection was  using the paraloid B-72 with a 3% concentration.

 

Keywords: coins, corrosion, lead, p-XRF, paraloid B-72, ultrasonic pen