The Ville de Montréal owns a significant collection of public artworks that require constant attention to ensure their preservation. To which municipal entity is this task entrusted? What is the city’s policy in this regard?
Snejanka Popova: The management of restoring and maintaining the municipal collection of public artworks is entrusted to the Public Art Bureau of the Direction de la culture et du patrimoine de la Ville de Montréal.
Over the years, the Public Art Bureau has acquired a wide-ranging expertise. Each restoration project is unique and requires specific knowledge and know-how. Our interventions are constantly being adapted to the needs of the work. Our goal is to restore or maintain the work’s integrity, respecting the artist’s intention and adhering to the principles of the main conservation charters.
In addition to counting on the specialized internal resources of engineering and heritage conservation, the Public Art Bureau works in collaboration with interdisciplinary teams, notably from the city’s laboratory, the Centre de conservation du Québec as well as experts from the architecture, engineering, traditional crafts and trades linked to new technologies and scientific research.
While carrying out the restoration projects, the Public Art Bureau uses the services of professional restorers, craftspeople and companies specialized in handling and transporting artworks, etc.
A team of blue collar workers, trained by the Centre de conservation du Québec, annually maintains a large portion of public artworks situated on the territory of the former Ville de Montréal. This team is responsible for removing graffiti, cleaning the works, replacing a protective layer of wax on bronze sculptures, etc. To slow the collections’ deterioration, the Public Art Bureau collaborates with the maintenance team to identify works that need to be looked after. We take special care of works located in highly frequented areas, as well as of recently acquired or restored works. The boroughs that were formed out of the former municipalities on the island of Montreal oversee the maintenance of the works located in their respective territories. They call on the Public Art Bureau’s expertise for the choice of products and the recommended intervention methods.
Though each case is unique, what are the techniques that are generally used for bronze pieces? Could you describe the various stages of the process?
The restoration methods for public art works in bronze must be chosen in view of ensuring the piece’s optimum conservation, as well as a good “stabilization and protection” for outdoor conditions. Moreover, in doing this we want to keep some of the signs of time passing on the sculptures and to respect their integrity in a reversible way.
Historical research and an inspection of the work’s physical state precedes restoration work on bronze pieces.
The Main Stages of Protecting Outdoor Bronze Pieces are:
TAKE DOWN AND TRANSPORT, IF REQUIRED
This stage includes if needed, dismantling the sculptures from their pedestal, lifting and installing them on a truck for transport to the restoration workshop.
To prevent damage to works during the handling process, the Ville de Montréal prefers restoring the bronze components of a monument onsite rather than in the workshop. However, very often we must take the sculpture down to restore the pedestal’s stonework or replace the damaged assemblage components or anchorings of these bronze pieces.
Cleaning with water to remove all residues (dust, pigeon droppings, etc.) to analyze the bronze surface better.
The objective is to eliminate superficial corrosion and dust. Some restorers use the micro-abrasive technique (propelling a vegetable abrasive at an adjustable pressure, depending on the type of corrosion and deterioration); others, use high pressure waterjetting along with nylon brushes and a non ionic detergent. This stage ends in a cleaning, using water, soft brushes and anionic soap.
STRUCTURAL RESTORATION, IF REQUIRED
The reconstitution of missing pieces (based on photographs) or the replacement of bolts and ferrous or damaged assemblage dowels are sometimes necessary.
This stage begins by stripping down the patina to observe the sculptural details better. We then apply two layers of microcrystalline wax to protect the surface. The first layer of wax is applied to the bronze pieces, which have been preheated using a torch in order to reduce the porosity of the bronze as much as possible. The second layer of wax is applied cold. This protection creates a barrier between the metal and the corrosive environment. It also protects against pigeon droppings and graffiti, preventing them from impregnating the pores of the bronze.
At the end of the process, the restorer makes a report that includes photographs taken before, during and after the restoration work, as well as specification sheets of the products used.
TRANSPORT AND REMOUNTING, IF REQUIRED
This stage includes loading the bronze work on a truck, transporting it from the restoration workshop to its location and installing it on its support (pedestal, plinth, etc) with anchorings.
INSPECTION OF THE RESTORED BRONZE PIECES, 6 TO 12 MONTHS AFTER THE COMPLETION OF THE RESTORATION WORK
This inspection is carried out by the restorer in order to ensure that the metal has properly stabilized. If necessary, he or she will do some touching up and produce an inspection report as well as a maintenance estimate.
ANNUAL MAINTENANCE OF THE ALREADY RESTORED BRONZE WORKS
This maintenance is carried out by the city’s maintenance team on the basis of the maintenance estimate provided by the work’s restorer. Generally, the required interventions are cleansing with water and wax replacement.
Could you give us examples of public artwork restorations that turned out to be particularly complex?
Restoring the Monument to Sir George-Étienne Cartier (1919) was certainly a considerable challenge. It included reconstructing the cement structure that supports the terrace, restoring the granite components, rectifying the structural integrity of the sculpture standing atop the monument and restoring the bronze pieces. However, La Renommée (the Angel of Renown) was restored onsite, using scaffolding that was specially designed by experts. The seventeen human figures and the four bronze lions were taken down, transported and restored in the workshop.
Restoring Robert Roussil’s Migration was also a stimulating project! Created in 1967 for the Universal Exposition, the sculpture is made up of heavy cast iron pieces. Keen on keeping the raw material visible, Roussil never painted his outdoor iron cast sculpture. He protected them with “used oil” in order to preserve the grain of the casting. With photographs from the period and the artist’s participation, we reconstructed the two missing feet, cold welded the broken feet, removed the corrosion and applied two layers of penetrating oil.
Translated by Bernard Schütze
Snejanka Popova is an engineer at the Public Art Bureau of the Ville de Montréal.