Counter facade restoration, Duomo Cathedral Church MILANO
Restoration work in Milan Cathedral
The counter facade made mainly in Candoglia marble appeared extremely blackened by large amounts of deposits of black smoke from exposure of candle smoke and the presence of the openings of the main church, from which soot and smog outside of this ‘building can reach the stone surface.
The stone blocks were intact, without major problems if not punctual efflorescence positioned at the top of the central arch, where infiltration interest coverage.
All segments showed fillings made with epoxy resin applied during one of several maintenance of the structure dating back to the 70s of the ‘900. Unlike the original stilature mortar, very thin, these overflow over tan. Matter as a result of the aging process is turning color, replacing the initial transparency a yellow mustard that interferes with the delicate tone of marble. The seals are still a very good adhesion to the surface, so that their removal would cause damage to the stone surface. Only in some places were found raised ridges.
The occasional reconstructions of fragments of stone veneer or decorative details were also made of resin and had therefore the same phenomena of degradation described above.
Different signatures executed in graphite were found both inside and outside of the central balcony and the two monumental statues on either side.
The pink granite used for the portals appear to have the same problems of marble, mostly related to the interference color of the seals.
The bases and capitals of the columns, made of black marble, appeared graying and had some breaks.
A look at the counter highlights its architecture consists of modules monumental Mannerist, and the eight windows, from right to left, are: “The Martyrdom of St. Tecla (1860);” S. Ambrose elected Bishop (1855) and, above, “the Church” (1955); “Assumption of the Virgin” (1854) and, above, (The Trinity “(1955);” St. Charles Borromeo sells the principality of Oria (1855) and, above “The Synagogue” (1955); “St. Michael the Archangel “(1858). At the second span, to the left, the baptistery, the classical temple run by the Pilgrims.
The facade was the last part of the cathedral to be built. It was begun at the dawn of the seventeenth century. by Francesco Maria Richini and this project date back five portals and the four smaller windows. The work, however, was suspended around 1630 for the strangeness of this architecture compared to the Gothic cathedral. The yard shooting in 1807, according to the project of Carlo Amati and Giuseppe Zanoja. This was not completed until mid-nineteenth century when, after the window neoclassical, in 1827, it was decided to close the top with a huge lion’s head and with a dedicatory inscription to be placed in the frame of the central balcony.
Thorough dusting all surfaces with vacuums and brushes to remove surface deposits, extraction of soluble salts made with pack cellulose pulp and deionized water until completely dry surface.
The cleaning of the wall was carried out with gelled solution based on ammonium carbonate, specially formulated, applied with a brush and removed by brushing with a nylon brush and sponge that has allowed to remove dirt deposited in a controlled manner, even in nature After a slight oily passage made with machinery compressed air at low pressure (microaeroabrasione wet) allowed to perfect cleaning and obtain a more homogeneous and smooth.
The writing executed in graphite have been properly documented photographically before their removal at the end of the cleanup to leave its testimony.
The statues in marble of Candoglia, the windows of the upper and the bases of the columns were cleaned by pack of saturated solution of ammonium carbonate and cellulose pulp, with shutter speeds varying between 10 and 40 minutes. After removing the surface was brushed and washed thoroughly with deionized water.
Granite surfaces have been cleaned with the same gel used for the veneer marble according to the application method already mentioned above.
The elements in black marble were cleaned with the gel and then protected with microcrystalline wax applied with a brush and pulled buffer.
Grouting of small deficiencies was carried out with mortar made of hydraulic lime and aggregates of different grain size and color in imitation of the surface subject of intervention.
The color balancing was performed setting the goal of restoring the correct reading of the whole. It has thus opted for a touch-up camouflage sealings tacks, intonandole one by one with the different shades of tan and recreating the look of the original stilature, with thin threads of light.
The entire project was completed with color silicate interior, unalterable, applied with a brush and sponge.
The bronze letters that make up the inscriptions above the main portal were treated with specific cleaner for metals and golden patina integrated with gold wax.
Veneranda Fabbrica del Duomo
TECHNICAL REPORT FINAL RESTORATION
Restorer Eros Zanotti
Dott. Ing. Benigno Morlin Visconti
Superintendence for the architectural and landscape of Milan
Dott. Arch. Giovanni Battista Sannazzaro
Skills : Stone sculptures