Restoration of artistic stained glass

RESTORATION OF STAINED GLASS IN THE BASILICA OF ST. MARK (VE)

Conservation and restoration work involving artistic stained glass was carried out in accordance with precise and strict working sequences that envisaged the following stages: Historical Analysis Historical execution techniques Analysis of the static structure (installation site) Analysis of conservation status Analysis of the deterioration status of the painting Action required Historical analysis and research into the techniques used to make stained glass requiring restoration envisage exact and precise identification of the original typology and methods to ensure appropriate action.

Analysis of the static structure ensures precise identification of the restoration work methods, define the possibility or otherwise of removing the windows from eventual metal structures or walls where they are installed. The intention is to avoid subjecting the stained glass to stresses caused by harmful tensions or vibrations.

The stained glass windows are transferred to the workshop where the individual components are mapped, followed by analysis of their conservation status. Lancets are then used to analyse strata of dirt and the deterioration of individual panels in order to define targeted action. Very often, the sulphur dioxide in the air penetrates deeply into the glass itself and corrodes it. Ancient stained glass works also often have missing or broken pieces.

Such ancient works of art - of different styles over the centuries - may have been made not only with the grisaille technique but also using copper oxides and silver nitrates. Such a work may suffer from flaking or have grooves that must then be rebuilt strictly in keeping with the original layout.

Restoration work as such involves several stages that, on the one hand, make it possible to save the stained glass artefact and, on the other, to re-install the leading and reinforcement soldering. The stained glass is cleaned with solutions of deionized water using appropriate buffers and depositions are removed using a lancet and glass fibre brushes; lastly, the deteriorated portions of the work are re-stabilised.