The Northwest Chapter recently visited Italy where we dedicated the restoration of Arnaldo Pomodoro’s Sfera in honor of our Northwest Chapter’s co-founder, Thomas S. James, Jr.
This sculpture, was donated by the artist in 1990 to the Vatican Museums where it was installed in the Pinecone Courtyard. The work is particularly striking in the architectural context of the courtyard, flanked on one side by the Dome of St. Peter’s Basilica and the other from the monumental niche of the Pinecone. The sculpture is part of a series of similar spheres by Arnaldo Pomodoro and exhibits both in Italy and abroad.
The artist created this particular work by duplicating the same dimension of the golden ball topping the Dome of St. Peter’s. Pomodoro, who was trained as a goldsmith, intended a play of opposites with his work; the outside is highly polished, smooth, and homogenous in its spherical shape, but wide fissures show a glimpse of the dark and complex interior made of gears and geometric mechanisms. It is in contrast to the exterior, symbol and metaphor for the dramatic confrontation between inside and outside, spirit and matter. The Sfera, despite its colossal size, can rotate, and is operated manually. It is said that that the sculpture can also be activated by the wind blowing over Rome at sunset, giving the spectator a unique play of light reflections.
State of Conservation
The works has fortunately retained the original smooth external surface which contrasts with the interior. This was in part due to the constant vigilance of the laboratory restorers of the Vatican Museums who work in the Department of Conservation of Metal Objects. Also important was the period maintenance by the Museum staff who regularly cleaned the surface and applied special protective layers for conservation. In spite of these controls, however, the work presented degradation typical of a monumental public outdoor sculptures, subject to pollutants , atmospheric precipitation and temperature fluctuations as well as dirt and smog deposits. Both other and inner surfaces were marked by bird excrement, which interrupted the continuity of the sculpture’s reflective surface. These layers of animal waste had calcified, and the previous layers of protective film has aged and become crystalized, dimming the luster of the outer surface. The interior surfaces contained a number of surface deposits. Birds nests, along with plant matter and growth were evident, carried in by wind and animals. The rough inner surfaces showed signs of light-colored powder from corrosion. All of these changes favored the persistence of pollutants and moisture on the surface, and furthered corrosion. In one areas, the metal surface had lost its mirror-like polish and was strongly oxidized. The welding for the assembly of the interior parts showed many pieces that were perfectly smooth and uniformly repaired, with a mirrored surface.
The restoration began with the complete photographic documentation of the work, paying close attention to the state of conservation of those areas affected by corrosion. The team graphically mapped out the conservation status in table format based on the photographs. The restoration operation began by preliminarily cleaning the surfaces; washing was carried out with controlled pressure washers and soft brushes were use to remove more substantial deposits. From the deposits taken from the mechanically cleaned zones, shapes were retained for further analysis. At the end of repeated washing operations, restoration work continued by removing all previous protective layers from the surface.
This operation was long and complex, due to the strength of the old protective layer, and the limited accessibility to the recessed portions of the gear mechanisms. The next step concerned treatment with a corrosion inhibitor. All areas of the city that had a powdery appearance received a cysteine solution application. the work continued with polishing the surface of the sphere, and its “teeth” using a fine abrasive paste.These operations were carried out manually and with the aid of electric hadn’t sanders. During the polishing phase, each zone that had lost its mirrored surface due to oxidation was treated and polished. The oxidation was removed with soft steel brushes mounted on a small motor drill, followed by repeated passages with sand paper. Afterwards, the restoration team applied polishing wax to the surface. The sculpture was then dusted with compressed air, brushes and vacuum cleaners, to prepare the surface for the protective film layer. The final protective spray was applied in three layers, and required special authorization to work by the Director of Works to work while the Museums were closed to the public on Sundays. The rough and glossy dark surfaces were further treated with microcrystalline wax to emphasize the difference between the shiny and matte surfaces, respecting the original aesthetic effect. The restoration team documented the conservation state and techniques via mapping procedures and photographs before, during and after the process.