A Survey of Stone Consolidation Methods: The case study of a sculptural monument at Forest Lawn Cemetery
Lauren Paige Isaacs
As a conservation student working with a generalized knowledge of outdoor stone deterioration and viable treatments options, Ms. Isaacs confronts the problems of acidic deposition on calcareous stone using the Pratt Memorial at Forest Lawn Cemetery as a case study in Buffalo, New York. The selected monument was erected in the late nineteenth century and has since suffered from prolonged exposure to acid precipitation resulting in severe granular disintegration (also referred to as ‘sugaring’).
For this project, the original stone was classified as dolomitic limestone using XRD (X-Ray Diffraction) analysis. Comparable weathered stone samples were obtained and similarly classified with XRD for evaluating potential treatment options. After a review of current and traditional treatment approaches for granular disintegration of limestone, four possible consolidation treatments were selected for evaluation. These options included: lime water washes, low viscosity epoxy in solvent mixture, commercially available alkoxysilanes, and alkoxysilanes with the inclusion of acrylic resin (Paraloid B-72).
Following treatment, the samples were subjected to accelerated aging using a series of controlled freeze thaw cycles to approximate a climate, such as Buffalo, over a twenty year period. The samples were then evaluated against each other and a negative control for changes in surface appearance by using photomicrography, depth penetration and overall coverage by viewing cross-sections with SEM (Scanning Electron Microscopy), and imparted strength by using a modified ASTM International Testing standard for spot abrasion.
The results of this research indicated that for this particular case, alkoxysilanes with the inclusion of acrylic resin performed the best overall. From this investigation it is evident that stone, its deterioration, and possible treatment options cannot be generalized. For every case of stone degradation in an outdoor environment it is crucial not only to accurately characterize the stone in question, but also the environment it is exposed to over time, as well as consider how the two will interact with the inclusion of a consolidation material.
Lauren “Paige” Isaacs specialized in the conservation of objects at Buffalo State College where she earned a MA and CAS in Art Conservation. She grew up in Nashville, TN and received a BA from Washington University in St. Louis in 2004. Paige was compelled to pursue a career in Art Conservation after studying abroad in Siena, Italy followed by a pre-program summer internship at The Frick Collection in New York City. She spent the following year as a conservation intern working full time at the Denver Art Museum in Colorado before entering a program of formal training.
While pursuing her master’s degree, Paige was a part of the Gulf Coast Recovery Project, where she assessed, stabilized, and treated museum objects for various institutions across the Gulf Coast affected by Hurricane Katrina. After completing her formal training in Buffalo she moved to New York City to complete a practical year of training while working at the Museum of Modern Art. Paige continues to live in New York City working as a freelance conservator through her private practice for various museums, galleries, and private clients throughout the area and beyond.