The Cruz de Cerrajería (the locksmith’s cross) (Seville): materials, degradation process and restoration methodology

Abstract

The Cruz de Cerrajería is a wrought-iron cross forged in 1692 by the master locksmith Sebastián Conde. Its exposure to environmental elements, its structural characteristics and the inappropriate application of superimposed coats of paint have given rise to severe degradation due to corrosion. By means of instrumental analysis techniques, we were able to accurately identify the causes of the deterioration, determine the characteristics of the metal and evaluate its response to the application of passivation and stabilization treatments. Through an experimental approach we were able to determine the most appropriate solutions regarding the restoration and protection measures adopted to combat corrosion, considering the application possibilities according to the typology and shape of the numerous pieces that form the Cruz de Cerrajería. The treatment studied here guarantees the adequate protection of the cross, water evacuation and prevents galvanic couples.

Keywords

• par galvánico
• forja
• oxidación
• estratigrafía
• pasivado