Color Cement Handicraft 8

Color Cement Handicraft 8

COLORS MAY BE GLAZED, MAT OR DULL FINISH according to how and when it is

placed on the cement tile. Each finish requires different treatment and

the easiest is the Dull Finish.

 

THE DULL COLOR FINISH is produced when the color is dropped or placed

into the mold and concrete or cement is used as a backing. This results

in the color drying in the mold with a dull finish next to the plaster

mold surface and is exposed when the cement casting is released from the

plaster mold.

 

THE GLAZED COLOR FINISH is more difficult to produce successfully and is

secured only in that color that is placed onto tile or pottery surfaces

after the cement surface has partially hardened. A tile design or

pattern may be cast in a mold and after it has come out of the mold it

is dried for an hour and then placed in water. If the surface to receive

color has been roughened or lines scraped into it when first released

from the mold and the cement slightly soft, the color will adhere even

more surely. We know that metal craftsmen often roughen the surface of

metal where enamels are to be placed and fired in, to insure more

perfect attachment, and a similar treatment to the cement will do

likewise for the cement color. When the cement tile has been removed

from the water and surplus moisture shaken off a little plain neat

cement is placed on the surfaces to be colored and to this the color in

thin paste form is dripped from a brush. No back stroke is possible

without injuring the finish. Finish each section and then leave it

alone.

 

A SAFE WORKING METHOD is to place the tile in shallow water to avoid any

part becoming dry while the color is being applied. A pan or shallow

dish will serve the purpose.

 

THE MAT FINISH is produced the same as for the Glazed Finish excepting

that the tile is placed in water immediately after it is removed from

the mold and placed there for a few minutes only. The surface is treated

otherwise similarly to the glazed process and this results in the color

being dull in finish.

 

HARDENING IN WATER should be done with all tiles and the dull and glazed

finished tiles should be set in a pan of water without letting the water

reach the decorated surfaces.

 

A COLORED SKETCH should be made in every instance where color is to be

applied to cement.

 

MATERIALS FOR MIXING COLORS are as follows: Two sizes of small

sable-hair brushes, a palette knife (or putty knife), several small

dishes, a spoon, a fine-mesh sieve, and a piece of glass.

 

TO MIX THE COLORS proceed as follows: Place a little of the desired

color on the glass, to this add dry cement reducing the color intensity

to the desired strength. Portland cement being gray will do this

harmoniously. To this add a few drops of water until the color is of the

desired consistency.

 

The color should always be tested on a tile surface and dried in the sun

to determine final color, adding color or cement to the wet mixture to

correct the color. Where a tint of color is wanted a white cement should

be added instead of Portland cement.

 

To produce a plain surface color on tiles, the desired quantity of color

is mixed and strained, to eliminate all coarse particles. The mixture

may be sifted while dry or strained after the cement has been added.

 

THE USE OF WHITE CEMENT should be limited because white cement is not as

durable as gray cement and because its setting qualities disappear as it

becomes older more rapidly than gray cement. If perfectly fresh it can

be used with good results and produces a more brilliant color when mixed

with the colors than when gray cement is used.

 

TO APPLY THE COLOR either in the mold or to the surface of the object

after it is removed from the mold, the color should be applied with a

brush.

 

AS A TEST COLOR PROBLEM use an incised pattern plaster mold and the

colors may be planned for the incised tile as follows: Working from a

color sketch, mix up colors to match and after the plaster mold has been

water soaked it should be oiled by dabbing the brush up and down on the

surface. If the brush is stroked it will not leave enough oil on the

surface and the color will stick to the tile. Next drip the cement color

from a brush with a shaking motion. The various colors are thus placed

in each of the partitions of the mold and after drying for fifteen

minutes is backed with a layer of plain cement and sand and allowed to

set.

 

When the tile is released it will contain different colors between the

incisions and a thin wash of an additional color may be added to fill

the incisions.

 

COLORS CAN BE MIXED one with another while dry or when wet to produce

other shades. Violet will be produced by the mixture of mineral orange

and ultramarine blue.

 

PLAIN SURFACED TILES MAY BE COLORED by pouring in a thin layer of color

combined with neat cement and then backed up with a concrete mixture.

Mottled and variegated color surfaces may be secured by first spattering

or dropping drops of another color into the mold before the color

mixture is poured in. Or the plain cement or concrete tile can be

removed and covered with a color layer which will be dull or glazed in

finish.

 

A PLAIN TILE TO BE APPLIED WITH COLOR should be placed in water

immediately on being removed from the mold, and allowed to remain there

for a quarter of an hour, before applying the color. When taking the

tile out of the water do not let the fingers come in contact with the

surface to be colored. Let the tile stand a few minutes to drain, before

applying the color. Then a thin layer of neat cement mixed with water is

applied. Next place a spoonful of the color upon the surface of the

tile, slightly shaking the tile while level, then pour off the surplus

color as it overflows the edges. If bubbles occur the surface should be

recoated for the bubbles will break in the drying, producing a defect.

To prevent bubbles, the color should be stirred with the spoon slowly so

as to avoid the arresting of air which produces the bubbles. The point

of a pin will often help to dissolute the bubbles if used immediately

after the surface is coated. When satisfactorily coated, place the tile

carefully in a tray and add water until it reaches a little more than

half way up the side of the tile. Be careful that water is not splashed

or dropped on the newly coated tile, for this will ruin the surface and

necessitate doing the tile again. The tile should remain in this water

for four or five days, water being added when it has become absorbed or

evaporated.

 

TO COLOR AN INCISED DESIGN the plaster cast from the original becomes

the mold for the color cement tile. The plaster, having become

thoroughly dry, is shellaced with one or two thin layers of shellac and

after drying for one or two days is ready for use with color cement.

 

It is then oiled well but not so that surplus oil remains on the

surface. A dry brush will be good to use for removing surplus oil. The

color having been mixed to harmonize with the previously prepared color

sketch, one of the color mixtures is taken up with a brush and dripped

with a shaking motion onto the correct area, which in an incised design

is divided into spaces. If a drop of color falls where it is not wanted,

take a clean brush and pick the color out of the space, after which a

little oil should be brushed carefully into the space to renew that

which was removed with the misplaced color. If any color falls onto the

back of color already placed do not worry over it as it will not appear

on the finished surface.

 

ANY COLOR NEXT TO A FILLED SPACE may overlap the previously filled space

as only that color touching the plaster surface will be visible when the

tile is removed from the mold and is finished.

 

AFTER COVERING THE ENTIRE SURFACE WITH COLOR let it remain for half an

hour before backing it up with the concrete mixture, as otherwise the

weight of the concrete may force gravel particles through the thin color

deposits and mar the face of the color design.

 

TO COMPLETE THE TILE remove after two days, and place in water after the

edges and slight faults have been corrected. It should harden in water

for several days and then dry in a cool place after which it can be

waxed or finished in other ways.

 

ANY OF THE PREVIOUS PROBLEMS described in the methods for producing

tiles in plain cement can be carried over into this chapter and color

added to the texture finishes in cement and concrete and many

interesting finishes developed.

 

OLD COLOR AND CEMENT or dried cement color should not be used. Mix up

only enough color for immediate use as any color not used fresh after

mixed with cement cannot be used again and should be discarded.

 

[Illustration: Use of Color in Cement Tiles]

 

[Illustration: Color Tile Methods

 

1. Relief Tile.

2. Persian Relief.

3. Relief Line with Mold Color.

4. Relief Line, Majolica Color.

5. Intaglio Tile.

6. Sgraffito Tile.]

 

 

 

 

[Illustration]

 

CHAPTER 6

 

Color Cement Relief

Tiles

 

[Illustration]

 

 

TO BEGIN A RELIEF TILE, a model should first be planned on clay or

modeling wax. A pencil pattern is first made on paper and this paper is

placed over the layer of clay or wax and a pencil tracing will produce

an indented pattern of the subject on the clay or wax underneath.

 

TO MODEL THE SURFACE a wooden modeling tool, such as is used by

sculptors, or a leather modeling tool or even small whittled pieces of

wood can be used. In producing raised portions the clay or wax scraped

to produce low parts can be used and care should be taken not to produce

too great a relief as a tile design should not appear detached.

 

AVOID UNDERCUT SURFACES or overhanging edges on the finished model as

this will result in locking of the cement cast with the plaster mold and

breaking of the tile before it can be removed. A general checking over

of the different parts before the plaster cast is made will avoid many

of the overhanging parts going through as they can be easily located and corrected.