For someone who claims to work behind the scenes at the Art Gallery of Ontario, art conservator Sherry Phillips has become a familiar face to visitors over past few years. In 2013, the AGO decided to put its art conservation and restoration efforts on public display. Phillips and her team occupied a space opposite the Henry Moore Galleries where they spent four months providing much-needed TLC to one of the AGO’s most popular works, Floor Burger (1962) by Claes Oldenburg, before it went on display in a retrospective of the American Pop artist’s early sculptures at New York’s Museum of Modern Art. The public could ask Phillips and the other conservators questions about the process of returning “the burger” to a displayable condition, which included many hours of carefully re-affixing flaking paint onto the sculpture’s canvas buns with adhesive.

Earlier this year, Phillips started another painstaking project – the conservation of British artist Simon Starling’s Infestation Piece (Musselled Moore). Commissioned in 2006 for a 2008 solo exhibition at The Power Plant, the bronze sculpture, a replica of a Henry Moore sculpture titled Warrior with Shield (1954) in the AGO’s collection, was submerged in Lake Ontario for over a year. Its surface became populated by zebra mussels. Like much of Starling’s work, the piece brings together art history and the natural world to examine humanity’s role in changes occurring in social, political and natural systems.

Infestation Piece entered the AGO’s collection in 2008, and was on display in Walker Court for several months. During a routine condition assessment, more mussels than usual were found to be dislodged from the surface. “The byssus – the fine strands of thread that the mussel produces in order to grip to surfaces – was becoming brittle and the shells were dropping off,” says Phillips. “And, the metal was oxidizing. It was a case of two materials reacting as they do naturally, but it was contrary to our long-term plans for preservation and presentation.”

One would think that a conservator’s work consists mainly of the manual labour it takes to repair the damage caused to art by mishandling or the passage of time. Not so, especially with artworks consisting of unconventional materials.

“In art restoration, there are some things we know,” explains Phillips. “For example, we know a lot about the chemical composition of the paints or finishes used in paintings from the 18^th Century, and how they will change over time. The approaches to repairing damage to such works are established. But, with much modern and contemporary art, conservators are faced with new challenges, especially when artists have used materials – like food or, well, zebra mussels – that weren’t meant to last.”

Before starting work on conserving the Starling piece, Phillips had to conduct a lot of research. “I know way more about zebra mussels and byssus than I ever thought I would,” she chuckles.

Although the words “conservation” and “restoration” are often used interchangeably, there is a difference. In the case of Infestation Piece, the AGO is engaging more in the concept of preservation and re-treatability, with restoration work towards the final stages. With conservation, the conservator tries to preserve what still remains of the work. “Conservators are trained to work to the principle of reversibility; that any added materials are readily distinguished from original materials, and interventions can be reversed in the future,” explains Phillips. “Re-treatability is more realistic in the case of Starling’s sculpture; it is impossible to reverse the treatment given the nature of the object, so the treatment plan was designed so that anything that must be done to the sculpture in the future can aesthetically and functionally build upon the current efforts.”

With restoration, the conservator may add materials to return an object back to a former state. At present, Phillips is not replacing the mussels that fell off with new ones; she is using a special adhesive to keep the existing mussels in place, or is carefully reattaching mussels that had come off wherever there are pieces of byssus on the surface, an indication that a mussel had once been in that spot. Once the security of the existing shells’ attachment is improved, she will work under Starling’s instruction to add shells to ‘restore’ the intended appearance.

For a few more months, Phillips will continue her work on Infestation Piece in a sound-proof room with clear walls in the AGO’s Contemporary Tower. Because of the extremely precise nature of the work, the public will be able to watch Phillips, but won’t be able to interrupt with questions. “I go into the booth, put on my headphones, and can zone out for hours, undisturbed,” she says. “Once, though, someone banged on one of the windows and I jumped a mile. When I looked up, whoever it was realized what they’d done and took off. Looking down, there were several of the shells that I’d spent hours reattaching lying at my feet.”

Hear Phillips and Simon Starling explain more about the AGO’s conservation of the sculpture in this video from the gallery’s Conservation Notes series.