A less experienced gilder may have attempted to follow the original specifications with disastrous consequences. In 1983 the two copper domes on top of the Dubuque County Courthouse were gilded with 23 Karat Gold Leaf. Within 5 years the gold and primers began to flake off. The specifications for the work proved to be ambiguous and left out some critical steps. The domes were subsequently stripped and re-gilded.
Every different surface requires distinct treatments to ensure proper adhesion between the layers.
What works on bronze will not work on lead coated copper or cast iron. What works on lead will not be appropriate for steel or copper. The correct system for use on fiberglass will fail on most other substrates. And there are no standard guidelines to follow. Specifications that are available are inaccurate, outdated and misleading.