Laura Buchner and Chris Gembinski gave a fascinating presentation on the conservation of dalle de verre glass panels at the New York Hall of Science, a building erected for the 1964 World’s Fair. Unlike many buildings erected for world’s fairs, the New York Hall of Science was always meant to be a permanent structure. The Great Hall is a 90-feet high ribbon-like structure of dalle de verre glass panels. The exhibition during the 1964 World’s Fair, “Rendezvous in Space”, made use of the deep cobalt blue dalles, highlighted by bits of ruby, green and gold, which give the interior the appearance of stepping into the cosmos.
The authors presented a brief description of how dalle de verre panels were made, both for this building and for typical buildings of the era. According to the authors, 1964 was a transition period when Willet Studios, a manufacturer of dalle de verre panels, began switching from the poured concrete panels used at the Great Hall, to an epoxy matrix.
In 2005, BCA began restoring the Great Hall. The goals of the project were to preserve the “experience of the building” and to address most of the deterioration and moisture-infiltration issues related to the building, but it was acknowledged by all parties involved that it would be impossible to cure all of the moisture-related problems due to the nature of original construction materials. The authors explained how they treated the typical conditions–cracks, erosion of the matrix, spalls of the concrete matrix, cracked glass, biological growth, and exposed reinforcement mesh. They replaced several panels with new dalle de verre set in an epoxy matrix, and rearranged some existing panels to minimize differences in light transmission between new and old units. They repaired cracks by injection and surface-application methods, and used a consolidant and water-repellant to reduce further deterioration of the panels. They also used a migrating corrosion inhibitor to reduce corrosion of rebar in the concrete grid.
The presentation was clear, informative, and well organized, and the conservation work looks expertly performed. I enjoyed learning about dalle de verre, as I was not familiar with it prior to the talk. I especially appreciated the authors’ willingness to share their experience using specific products, and the steps they took to maximize the efficacy of these products.