William McKinley Monument

The William McKinley Monument is a bronze statue atop a granite base located in the Panhandle of Golden Gate Park. The Monument has been subject to recurring graffiti vandalism of multiple media types. The existing anti-graffiti coating was thick and milky-white in appearance, obscuring the color and texture of the granite pedestal and impeding water and vapor migration through the surface of the stone. The coatings were partially peeling from the granite surface.

ARG Conservation Services was contracted to remove the superficial graffiti and existing coatings from the granite, and apply a new, more aesthetically appropriate anti-graffiti sacrificial coating. When removing graffiti, it is particularly important to prevent the graffiti media from migrating into the porous stone and leaving a shadow. Conservation cleaning materials were tested and selected after taking into account the physical and chemical properties of the granite substrate and various graffiti media. The majority of the graffiti was successfully removed using an environmentally conscientious approach with a minimal amount of chemicals while still ensuring the long-term preservation of the monument. The new sacrificial coating allows for better water and vapor migration and provides an improved aesthetic for the stone base, and has allowed for subsequent removal of graffiti at this site.