Color Cement Handicraft 19

Color Cement Handicraft 19

THE CEMENT SLAB IS MADE by surrounding an oiled surface (wood or glass)

with wooden retaining walls similar to those used in making tiles. These

walls should be oiled and otherwise made proof against leakage of water

as it is necessary that all water in the cement be retained to perfect

the hardening. The mixture of sand and cement (one part cement and two

parts sand or gravel) is next poured into this space and permitted to

set for several hours. Over this surface a thin layer of neat cement may

be spread or dry neat cement sprinkled through a sieve and worked into

the moist surface with the flat side of a palette or other knife.

 

THE COLOR IS THEN APPLIED by mixing up the colors to be used into a

paste form and these can be applied with a brush or with a palette knife

shaping and forming the subject as if painting in ordinary colors.

 

If the color sinks in too rapidly and becomes lost, the under surface is

too wet and the painting should be delayed for several hours or until

the color applied lays upon the surface properly.

 

THE CEMENT SLAB IS TRANSFERRED TO THE METAL TRAY as soon as it is

removable from its surface. In fact, a good way is to move the wood or

glass under support with the cement slab upon it and place the whole

combination into the tray. If the sides are well set the retaining walls

can be removed, and as soon as the whole layer is set enough so as not

to be dissolved by water, water is poured in the tray until it comes

half-way up the side of the cement slab. This will prevent the whole

slab drying prematurely as the water will supply all that is needed. If

the water becomes absorbed more should be poured in. After it has

remained in the tray for a week, it may be withdrawn and permitted to

dry gradually. Wet cloths around it will prevent too rapid drying.

 

WHEN WORKING UPON THE SURFACE, the surface should be completed as the

space is covered, avoiding returning to work upon any part after it has

commenced to set. If the surface has formed a shell or thin layer and

reworking breaks this shell, the color in that section will not harden

properly. It requires direct, confident handling of the subject, and

reworking of the surface such as the painter in oils is accustomed to is

not possible with color cement.

 

A WHITE CEMENT SURFACE can be formed over a cement layer and when this

is nearly dry thin washes of color cement may be used onto the surface

similar to working with water color. The white cement will absorb the

color easily and parts of the design may be worked in opaque or solid

colors.

 

A DARK WORKING BACKGROUND may be used by mixing a layer of dark blue,

brown or green. A layer of black can also be used. Brilliant colors can

be brushed or dripped into this so that they sink and become a part of

the dark surface without being in relief. A slight shaking of the

surface or the tray will produce this amalgamation of colors.

 

WATER SHOULD NOT REACH THE COLOR SURFACE until after it is entirely dry.

To avoid water splashing onto the surface from the tray it is the best

policy not to pour water into the tray before the painting is completed

and only when the tray is to be left undisturbed.

 

TO CONNECT THE COLOR CEMENT MURAL with the building wall, the space to

receive it should be well moistened and covered with neat cement which

is well worked into the surface. The back of the cement mural is

similarly treated and the two cement surfaces are pressed together and

held in position by a brace or support until thoroughly dried. The space

or border edge around the panel should be filled in with cement at the

same time.

 

[Illustration: Decorations Painted with Color Cement]

 

[Illustration: Cement Color Painted Decorations Applied]

 

 

 

 

[Illustration]

 

CHAPTER 18

 

Tiles and Pottery

with Color Magnesite

Cement Work

 

[Illustration]

 

 

MAGNESITE CEMENT WORK is a mixture medium producing a hard marble-like

quality and does not contain any Portland cement, but is given in this

book in order to complete the possible plastic mediums for the worker

wishing to mold objects with permanent durable mediums.

 

MAGNESITE CEMENT IS A SUCCESSFUL INDUSTRIAL MATERIAL and is used by

builders in interior trimmings for floor tiles, in making of bath-room

surfaces and recently used in coating stairways and hallways, producing

a pleasing texture and durable surface. The material is fireproof,

cleanly and better than marble.

 

MAGNESITE IS A FORM OF LIMESTONE and is a carbonate of magnesia which is

produced by burning until all gases have been eliminated, leaving only

the oxide in the form of a pure white powder. It comes from Europe and

is found in Maryland, Massachusetts, New York, Vermont, California, and

Washington. It has been used extensively in Europe and when better known

will be used more generally in America.

 

MAGNESITE CEMENT AS AN ENAMEL has been used as a hardening surface on

concrete and cement surfaces and also on clay brick. The concrete or

cement or brick surfaces should be thoroughly moistened before the

magnesite mixture is placed upon it to avoid the moisture from the

magnesite being absorbed and improperly drying.

 

THE MATERIALS FOR PRODUCING MAGNESITE are calcined powdered magnesite,

chloride of magnesia, sulphate of magnesia, white sand, white talc and

fine sawdust.

 

The magnesite should be kept in a container, proof against exposure to

air and dampness, in order to preserve its full setting qualities.

 

Chloride of magnesia has the appearance of ice or alum and when exposed

has the tendency to dissolve but does not deteriorate. It is the

chemical which when united with the magnesite produces the binding or

cement qualities.

 

Sulphate of magnesia or epsom salts is an easily secured material and is

used in very small quantities in the formulae for producing magnesite

cement and which is given later in this chapter.

 

The white talc or soapstone used for giving a smooth and polished white

background is used as a filler.

 

White sand and the fine sawdust should be absolutely clean and are mixed

with the other ingredients to produce the composite mixture to produce

Magnesite Cement.

 

TO COMBINE THE INGREDIENTS proceed as follows:

 

FIRST MIXTURE. Two and one-half pounds of powdered magnesite and one

pound of white talc are mixed thoroughly with one quart of fine sawdust.

To this mineral, dry color similar to that used and described for color

cement should be added if a color tone is desired. About one-half as

much color should be used as there is magnesite. In other words, one

pound of color should be used with two and a half pounds of powdered

magnesite. A stone mortar should be used to grind the entire mixture

well together.

 

This first combination is a dry mixture and is then mixed with the

second mixture which is liquid.

 

SECOND MIXTURE. Take five parts by weight of chloride of magnesia

solution with a density of 25 tested with a Baumé hydrometer which is a

simple glass tube secured at any druggist for registering solutions. To

the chloride of magnesia solution add one-half part by weight of

sulphate of magnesia which is epsom salts and test with the hydrometer

until it records 15.

 

TO USE THE HYDROMETER, place water in a container and if the hydrometer

is placed in it, it will register “0” and when the chloride is placed in

it, and dissolves the hydrometer will commence registering the density

of the solution. When it records 25 no more chemical should be added.

More water should be added to correct the density if needed. The same

procedure is followed for registering the 15 for the epsom salts.

 

Chloride of magnesia will dissolve more rapidly if it is broken up, and

distilled water may be used if the usual available water contains lime,

iron or other injurious minerals. Some workers use rain water for many

purposes.

 

THE FINAL MIXTURE, or third step in the mixing, is to take the first dry

mixture and add enough of the second liquid combination to produce a

thick creamy mixture of the two. Strain this after it has been well

mixed.

 

TO PRODUCE TILES OR OTHER OBJECTS, THE MATERIAL is quickly poured into

the molds. A brush may be used for brushing the material well into the

edges and corners. A gentle jarring of the mold will remove the air

bubbles and the molds with the magnesite is permitted to dry for seven

to ten hours before the cast is removed from the mold.

 

FOR VARIOUS COLORS in the same design, the dry mixture can be mixed with

color and the liquid, or second mixture, added to it. This can be

applied to the mold in the same way as the color was used with cement,

and after it has set, can be backed with a general color of magnesite

cement or with plain magnesite mixture.

 

TO FINISH MAGNESITE let it remain drying for two or three days after

which it can be washed with slightly warmed water to remove the thin

scum on the surface. A thin coating of beeswax or floor wax well polished will finish the article.