Preparing Bole from Dry Clay
Materials:
Gluepot, double boiler, or bain marie
Animal collagen glue (we recommend
)(dry powder or cone)
Distilled water
Spoon
Procedure:
• Soak 80 grams of the glue in one liter (about one quart) of cold water for about 30 minutes.
• Warm up the resulting mass in a water bath until the glue is completely dissolved (See Tip No. 2).
• Gradually add small amounts of the glue solution to the bole and stir together well. To prevent the formation of air bubbles, stir the size and bole mixture slowly and thoroughly.
• The resulting mass takes on a dough-like consistency and becomes more liquid as the glue is added. Add glue solution to the bole until the mixture takes on the consistency of latex paint that can be smoothly applied with a brush.
Preparing Bole from Wet Clay
Materials:
Gluepot, double boiler, or bain marie
Animal collagen glue (we recommend
)(wet clay)
Distilled water
Spoon
Procedure:
• Soak 120 grams of the glue in one liter (about one quart) of cold water for about 30 minutes.
• Warm up the resulting mass in a water bath until the glue is completely dissolved (See Tip No. 2).
• Gradually add small amounts of the glue solution to the bole and stir together well. To prevent the formation of air bubbles, stir the size and bole mixture slowly and thoroughly.
• Continue adding glue solution to the bole until the mixture takes on the consistency of latex paint that can be smoothly applied with a brush—about two parts by volume of glue to one part by volume of bole. More water may need to be added to achieve the right consistency.
Applying Bole
Materials:
Sieve, soft-hair brush
Procedure:
• Pass the bole and glue mixture through a sieve (See Tip No. 3).
• Apply it rapidly to the surface to be gilded with a brush. Let each coat dry before applying the next one (See Tip No. 4). Apply at least two coats, but no more than four.
• When the final coat of bole is completely dry, smooth it with a brush (See Tip No. 5).
Applying Gold Leaf
Materials:
(loose or surface)
Wetting brush (any soft-haired brush such as a squirrel brush)
Wetting solution
Preparing the Wetting Solution (Gilding Liquor):
• Mix isopropyl alcohol (1 part by volume) and distilled water (2 parts by volume).
• Use a brush to apply the wetting solution to the surface of the bole immediately before applying the gold leaf.
• Lay a piece of gold leaf on the gilding pad and cut it to size.
• Pick up the gold piece with the gilding tip and place it onto the wetted surface of the gilded object. The gold leaf should overlap by about 2–3 mm along the edges.
• Blow the gold leaf gently into place, taking care to prevent the formation of air bubbles under the surface.
Burnishing the Gilded Surface
Materials:
Agate burnisher of the right type (See Tip No. 6)
See our selection of
Procedure:
Before burnishing, the base should have only traces of the wetting solution (See Tip No. 7). Once this stage has been reached (after about one hour in normal climatic conditions), rub the agate burnisher, using slight pressure, across the entire gilded surface. Ensure that no part of the surface is left untreated. Burnish the gilded surface until it is highly polished.
Tips
1. To ensure patches of the surface that have not been gilded correctly with gold leaf are not obvious, use yellow bole to hide these areas.
2. Place the pot containing the wet glue into hot water (maximum 50° C). The ideal implement for this purpose is an electrically operated water bath with thermostatic temperature control; otherwise, use a double boiler or bain-marie.
3. You can filter the solution through a fine-mesh material, such as an old pair of nylon stockings. Lumps and other impurities then remain inside the stocking.
4. Apply each layer “wet on wet,” i.e., without waiting for the previous one to dry completely. Add warm water to prevent the bole and size mixture from thickening too much. This will make it easier to apply with a brush, ensuring that it goes smoothly. When diluting the solution, stir it very slowly to avoid the formation of bubbles.
5. Brush the thoroughly dried surface of the bole with a brush before applying the gold leaf, ensuring that no part of the surface is left untouched. Apply firm pressure when doing so. This pressing action causes the base material to compress, giving the surface of the bole a porcelain-like shine.
6. The most versatile burnisher recommended for novices is a small tooth-shaped agate.
7. The right moment to begin gilding can also be determined using the so-called “knock test.” Carefully tap the gilded surface with an agate burnisher. If the tone produced is lighter than the dull one heard just after applying the gold leaf, test a small area at the edge of the gilded surface to determine whether the gilding is ready for burnishing. If it is, begin burnishing the entire surface. It isn't easy to burnish the gold correctly once the underlying surface is completely dry.