CHAPTER 16

Surface Finishes

COLOR CEMENT TILES ARE SURFACE FINISHED generally after they are dry. As the tiles or pottery dry a lime or white powder dries on the surface and the colors appear to become dull. To bring out the colors and remove this powder, a soft cloth or soft brush is used to brush or dust off the tile surface thoroughly.

AN OIL RUB can be given to the surface of the tile with raw linseed oil on a soft cloth, and a brisk rubbing of the cloth will give a soft dull polish. This should be done only on the cast and dull finish tiles and not on the slip-painted or glazed surfaces.

A THIN SHELLAC COATING may be given a color cement tile or pottery as a preliminary to a wax polish or a gasoline wash. White cement tiles or pottery are very porous and a thin coating of clear white shellac will prevent over absorption of surface coloring if the shellac is permitted to dry thoroughly. Shellac should be applied after the surface is thoroughly dried to prevent a sticky surface.

THE GASOLINE WASH is made by mixing white oil paint (flake white or zinc white) with black paint (ivory black or lamp black) until a gray tone is secured. This mixture should be made in a cup or bowl so that gasoline can then be added until the paint is almost as thin as water. To this mixture green or blue paint or other color should be added until the right hue is secured. This is then brushed onto the tile surface and brushed well into the crevices and countersunk sections as it is important that the low sections be well filled. After the wash has dried thoroughly, a soft cloth is used to rub off all the surplus. This will leave the gasoline wash remaining only in the bottom or lower portions giving a pleasing finish. After this has dried a wax rub may be placed over it.

A WAX RUB is produced by taking either wax tan shoe polish or floor wax and rubbing it onto the cement with a soft cloth. The cement should be thoroughly dry before the wax is placed upon the surface. After a few minutes a soft brush or woolen cloth should be used to polish the waxed surface.

A wax rub can be applied over a gasoline wash, but only after the wash has been given time to thoroughly dry. If the gasoline wash is not dry, the wax will remove it in parts and destroy the effect produced by the gasoline wash.

A COLOR CEMENT SURFACE FINISH is made by mixing a thin mixture of color and cement which is then brushed onto the tile. The tile or surface to be finished with cement should not be dry or be permitted to dry after it has been removed from the mold. Previous to the application of the cement color, the tile should be well moistened. After the color has dried for several hours upon the surface, a cloth balled or gathered so as to form a padded surface should be used to remove the color from the high parts.

A SLIP SURFACE FINISH is where the tile or surface has been completed in single or several colors and when hardened sufficiently in water, a thin slip of color cement is placed over the entire surface and permitted to settle into the hollows, leaving the higher portions to appear more clearly through the colored slip. If the surface is a tile, it should then be permitted to harden in shallow water placed in a tray with the tile placed carefully into it so that the water does not reach the color slip portions. If the object is a vase, it may be filled with water to harden the outer surface properly. If the color has been used as a layer on the inside, the bowl or vase should be placed in a pail and water poured into the pail so that the object is surrounded with water. A weight or board can be placed so as to prevent the object from floating if it commences to do so.

COLOR MAY BE SPRAYED by mixing a thin mixture of color and cement and spraying it onto the tile or pottery surface with a fixitive blower such as may be obtained at artists’ supply stores and which is used by artists for spraying a solution of shellac (termed fixitive) onto charcoal or pencil drawings.

The color should be repeatedly stirred to keep it well mixed and if the sprayer becomes clogged, it should be rinsed in water.

Too much color should not be sprayed at a time as it will fail to be absorbed and run on the surface, resulting in streaks.

SPATTERED COLOR FOR SURFACES is secured by dipping a short-haired bristle brush (the bristles are best when they are about one inch long) into color cement and causing the color to spatter onto the surface by rubbing a knife edge or straight edge of a stick along the brush. This will cause the bristles to release suddenly, throwing pigment in the opposite direction onto the object. A trial should first be made on paper surface before the actual surface is used to avoid too much color, such as would come from an overcharged brush or too vigorous rubbing. The surface of the object should be moist or dampened well previous to the spattering.

SPRINKLED DRY COLOR can be applied to surfaces. This will give a pleasing effect in certain places where an antique or scattering of dry color will enter into the nature of the design. The dry pigment can be sprinkled onto the surface only where the surface has been covered with a layer of other color that is still moist. This is necessary in order that the dry color will absorb sufficient moisture from the other color to amalgamate with the first color.

TEXTURE SURFACES are produced by working on the surfaces while they are still moist or soft enough to admit the use of a tool or edge to press or model the surface. Even when a surface might have become quite hard it may be tooled or chipped and a cement wash or gasoline wash used to give the tooled parts a unifying color.

REPEATED SURFACE COLORING may be done where the first coloring is not satisfactory. It will be found that a more pleasing effect is often produced by the second surface coloring being placed over the first. Care should be taken that so much rubbing does not occur that it wears parts of the tile or pottery surface that are soft.

SURFACE FINISHES PERMIT OF EXPERIMENTING and the craftsworker in color cement must test out different combinations in order to achieve the most desirable quality to respond to personal choice. A brilliant color wash will often bring out the pattern in pleasing contrast, and at other times it may be over absorbed and produce a mottled undesirable quality. The condition of the molds and the amount of sand in the mixture all influence the surface of the object and in turn influence the result of the surface finishes.