Cast zinc was in common use for monumental and decorative statuary during the period just prior to the turn of the 20th century. Zinc, a metal less costly and easier to cast than bronze, was marketed as “White Bronze” in an effort to associate it with the perceived value of the better known statuary metal. Designs as well as inscriptions were also intended to recall traditional materials through the use of the rustic faced courses, reference to stone in inscriptions and occasionally, bronze powder aint faux finishes.
Zinc proved to be less permanent than it was originally proclaimed to be and its use in monuments declined in the early 20th century. The inherent qualities that proved to be troublesome for monumental use were its brittleness, tendency to slump from metal creep, and its sacrificial galvanic qualities when combined with other metals. The structural weaknesses lead to early failure of larger structures that deformed and cracked under their own weight. These monuments were generally not created with internal armatures. In poorly engineered works the zinc also corroded due to galvanic action when in contact with other metals. Nevertheless, properly detailed monuments that did not exceed the design limitations of the metal continue to survive in excellent condition in many cases.
The author has treated several zinc outdoor monuments that have required the creation of an internal structural armature to support the slumping or cracked metal forms. Each was specially designed to stabilize the monuments without introducing contact between differing metals and the likely galvanic corrosion that would result. Armatures had to accommodate the specific designs of the monuments and be installed through minimal intervention into the existing sculptures. He will discuss these treatments as well as review other, less successful means that have been used in reinforcing zinc monuments.