Architectural gilding on exterior metal: An overview of materials and methodology

Michael W. Kramer


Methods and materials for gilding have changed considerably from the historic origins of the craft up to modem times. Historic techniques including flame gilding with mercury/gold amalgams proved to be highly effective in attaching gold to a copper surface, but very detrimental to the health of the gilders performing the work. Lead compounds once in common use as primers and undercoats have been legislated out of existence. The use of zinc chromate and other chromium compounds has became highly restricted in many jurisdictions. At the same time, the conditions an exterior gilded object is exposed to have become more demanding than ever before.

Environmental regulations have had a tremendous impact on all aspects of exterior gilding. From preparation to priming to finishing, the gilder needs to research and keep up with the different materials available from region to region. Beyond conventional primers and undercoats, there is a new generation of moisture cured and catalyzed primers, undercoats and sealers that have been developed for exterior metal. Coupled with this is the introduction of acrylic adhesives during the last few years. The suitability and uses of these materials on actual projects will be explored.

Installations including exterior copper, lead coated copper and bronze will be reviewed with an emphasis on how new materials and techniques are expected to perform compared to more traditional methods. More changes in materials are anticipated. How the materials are changing and the impact this is having on the craft is already becoming evident in certain areas of the country.

1995 | St. Paul | Volume 3