Co-cathedral enters another golden age

The arches along the main nave of St John's Co-Cathedral in Valletta have been restored to their original splendour in an extensive project that cost about €530,000.

The arches were damaged by the dampness and the accumulation of dust and grime over time and it took the Italian and Maltese restorers almost two years of meticulous work to reveal their former beauty.

The project was funded by the St John's Co-Cathedral Foundation and entrusted to Sante Guido restorers from Italy.

The cathedral is often described as Malta's gem. Now, it sparkles even brighter. After the recent controversy that raged over the foundation's proposed underground museum, the focus can now shift to the exquisite grandeur of the cathedral's interior.

The grandmasters of the Knights, who took great pride in their conventual church, wanted it decorated in a Baroque style. The process of decoration lasted from the 1650s to the 1660s and it was only after Mattia Preti painted the vault that the nave and chapels were adorned with elaborate motifs, transforming the walls into a riot of richly gilded foliage, flowers, angels and triumphal symbols.

As a result, the restoration of each arch and the interior wall of the façade entailed an initial detailed study of each arch, taking into consideration the gilding technique, the state of conservation, old restorations and materials as well as factors of deterioration.

Samples were taken to understand the constitutive materials of several arches as well as for comparative studies.

The arches suffered from dampness, salt migration to a height of approximately three metres, loss of gold and original paint layers, over paintings in tempera and oil medium and application of linseed oil.

Tests were carried out on each arch to ensure the cleaning method was suitable for all arches.

The restorers then started from the top, removing all dirt and grime using aqueous solutions applied by brush and working on the surface with a circular motion, followed by thorough rinsing with de-ionized water.

Lower areas that had a high content of water and salt florescence were rid of salts using absorbent materials and techniques. Thick layers of linseed oil were removed using poultices of alkaline solutions.

In all methodologies, rinsing the surface from all products was extremely important to stop any action on the surface that could cause further damage.

Unstable and detached stone or paint layers were consolidated while old, weak in-fills were removed and replaced with fresh plaster. Cracks and other losses were filled in with the same reversible material to attain continuity of decorative surface.

Once the structural work was wrapped up, areas that had loss of paint layers were repainted using reversible water colour technique and then gilded.