I think that after a 60-year history of acrylic coatings that we would have a good understanding, with very specific data, on the longevity of acrylics in outdoor environments. I have seen exposure test samples of original acrylics from the Rohm & Haas test facility outside Philadelphia of a coated wood panel set out in 1954 that are in incredibly good condition; no breaks at all in the film and very little color loss. And I have also seen test exposures of coatings on metal panels in test facilities in South Florida that after 3 years have totally been destroyed.
The specific aging data on outdoor murals painted in acrylic coatings is not available. We have a great deal of anecdotal information and examples that have lasted well over 20 years and those that have not lasted two years. Our oldest example of a mural with GOLDEN acrylic dispersion paints was conceived, developed and executed by artist Archie Rand in Jerusalem, in 1984. The murals consisted of seven enormous panels depicting the „Creation Story.“ The paints have held up well, except for significant changes in the yellow over the last 24 years. The mural „West and North“ 1987, by Norman Yates in Edmonton, Alberta Canada, composed of hundreds of painted 4 foot by 8 foot panels, has endured the Canadian climate with little change. The mural „Homage to Seurat: La Grande Jatte in Harlem,“ painted by the late Eva Cockcroft in 1986 in Manhattan, has a great deal of flaking and many of the reds and yellows have changed to pastel in color. All these murals were painted around the same time, yet in very different environments and in very different conditions.
What causes some murals to last for decades and others to begin to fail soon after completion? Unfortunately, we are only beginning to understand the dynamics that affect these public artworks. Yet while we do this, many major murals by significant artists are being destroyed, most for reasons not related to the materials. Saving our public legacy has been the mission of the group sponsored by the Heritage Preservation, formerly the National Institute for Conservation. This group called „Rescue Public Murals“ (RPM) has been co-directed by Dr. Timothy W. Drescher and Will Shank, both with considerable credentials in art history, murals and art conservation, beginning in 2006. Its mission has been to identify the inventory of significant works around the country and to assess and potentially remediate conditions that have led to the works‘ state of disrepair or potential destruction. As one of its first public efforts, RPM has established a best practices section on its website.
I am most excited about a new effort led by Mark Gottsegen, the Administrator of the Art Material Information and Education Network, (AMIEN). Mark has already gained the commitment of colleagues in paintings conservation and mural artists to develop a testing program to begin to monitor how well the coatings used in outdoor murals withstand the various environmental conditions which they face. Using a portable spectrophotometer to measure changes in the coatings over time, AMIEN will begin to assemble data that will replace a good deal of the conjecture and rumor with real information. Eventually we hope that AMIEN will be able to convince many communities with a significant mural program to support this effort with a minimal investment, but with a tremendous payback to improving data and eventually information for best practices. AMIEN is currently in the beginning stages of this work and commitment to collaborate with RPM as both of these organizations advance the goals of preserving public art for generations to enjoy.