Gold Gilding

  • Gilding: the application of gold, silver, or other, leaf to a surface
    • Adhesive is applied to a clean and smooth surface of the item being gilded.
    • The gold leaf is then pressed on to the adhesive, and the excess leaf is brushed off.
  • Surface preparation is important.  A clean smooth surface works best.
    • Because the gold leaf is very very thin, any imperfections in the surface will show.
    • The surface preparation will differ depending on the base material.  Wood, metal and glass are the most common.
    • When gilding a metal object, the surface needs to be clean and smooth. 
    • Many gilders use shellac as the base coat, as it is a wonderful sealer. 
    • The surface should be lightly sanded and clean to allow the shellac to adhere properly. 
    • Once the shellac is applied and dry, you can lightly sand with a very fine sandpaper and then apply the gilding size.
  • Fire-gilding or Wash-gilding: a process by which an amalgam of gold (gold dissolved in liquid mercurymetal) is applied to metallic surfaces, the mercury being subsequently volatilized, leaving a film of gold or an amalgam containing \n 13 to 16% mercury.
  • Preparation of the amalgam: the gold must first be reduced to thin plates or grains, which are heated red-hot, and thrown into previously heated mercury.
    • When the mixture is stirred with an iron rod, the gold is totally absorbed by mercury.
    • The proportion of mercury to gold is generally six (or eight) to one.
  • The gold amalgam is equally spread over the prepared surface of the metal, the mercury is then evaporated by a heat.
  • When the mercury has evaporated, the gilded surface is rubbed with a scratch brush of brass wire, until its surface is smooth.
  • It is then covered with gilding wax, and again exposed to fire until the wax is burnt off.
  • This process, when skillfully carried out, produces gilding of great solidity and beauty, but owing to the exposure of the workmen to mercurial fumes, it is very unhealthy.
  • There is also much loss of mercury to the atmosphere, which brings extremely serious environmental concerns as well.
  • Sealing will prevent oxidation and color change in leaf that does not have a high gold content.
    • Sealing gold or silver will result in some loss of brightness and shininess.