Most if not all cemetery metalwork traditionally received some type of coating for protection. The application of paints and coatings are therefore both historically appropriate and necessary to preserve the decorative metalwork.

Metalwork Protective Coatings

Before any new finishes are applied, the metalwork must be thoroughly cleaned, and all small holes and pitting that might hold water should be filled with a quality patching material designed for metal.

A coating system should be selected that can be easily applied depending on the application context (on- or off-site). Only paints meeting all the current health, safety, and environmental standards should be used. Acrylic paints are building a relatively good track record for protection of metalwork and should be used over other irreversible coatings such as epoxy based paints.

Paints and coatings should only be applied when surfaces are perfectly dry and temperatures are above 50 degrees F. Brush applying paint insures the best coverage. If railings are removed, they can be spray painted in a controlled environment followed by "back-brushing" to ensure that the paint is worked into the surface and into all joints.

Three-coat work consisting of a primer, intermediate, and finish coats is standard for bare metal. A good quality corrosion inhibitive, "direct-to-metal" (DTM) primer should be used followed by two compatible finish coats. If the paint is applied in thin coats, there will be better adhesion, build-up will be minimized, and the detail of the metalwork will be less obscured.

Archival evidence suggests that architectural wrought iron was sometimes wax and oil treated, rather than painted. In these cases, a microcrystalline-based wax formulation can be used to protect and enhance the metalwork. This method has been extensively used with success on outdoor bronze sculpture and at St. Louis Cemetery No. 1.

The wax mixture is applied hot to a previously cleaned and heated surface to chase off condensed moisture on the surface and to insure adequate flow of the wax for complete coverage. Different formulations are possible, including mixtures of microcrystalline and low melting point polyethylene waxes with pigments such as lampblack, and are best prepared and applied by a professional conservator.

See the full discussion of metalwork cleaning, protection, repair and replacement options in the St. Louis Cemetery No. 1 Guidelines for Preservation and Restoration. The full document of guidelines can be downloaded as a pdf file. Go There.