Gold Plating in Statues

RAW MATERIALS

The chief raw materials necessary for gilding are gold and mercury that has been traditionally been obtained from the red hingul ore by gilders and goldsmiths. This substance is used for the extraction of mercury. Hingul is also used as a colour for painting the face of the red machhindranath. The proportion of gold required to mercury is usually 1:4 tolas. Another part of the raw material mix is made up of magito (manjista /Rubia Cordifolia), a plant used in natural dying.

PROCESS & TECHNIQUE

The process of gilding a surface has remained the same for centuries. At the first stage an amalgam of gold and mercury is prepared. The gold is hammered into very thin sheets, which are then cut up into tiny bits. These tiny bits of gold are put in a mortar into which some mercury, salt, and a sour-liquid (chuk) is added. The whole mixture is ground into powdery sand grains. At this stage some more mercury is added, and the grinding process is repeated about three to four times. The grinding is considered complete when the mixture is tested -by rubbing on the palm of the hand - and the layer of gold rolls up and does not break.

In the meantime, the icon or surface to be gilded is rubbed vigorously either with citrous fruit or chuk, or common salt and chuk in order clean it. Burnt bits of black bricks are also used for scraping the surface clean. This is followed by a thorough water wash. The surface to be gilded is then given a coating of the finely ground mixture of gold amalgam. As the coating dries the surface appears white. The icon is then heated in a cow-dung fire - during this process the mercury volatilises producing a crackling sound accompanied by white fumes. When the heating process is complete the surface of the icon has changed from white to a reddish tone. At this stage a decoction of the majito herb is prepared and poured over the hot reddish-hued surface - through this process the gilded surface acquires a dull gold tone.

The final finishing is through by rubbing the surface with a hard agate stone till a lustrous and glossy bright yellow-gold colour is obtained.