This section is from the "Henley's Twentieth Century Formulas Recipes Processes" encyclopedia, by Norman W. Henley and others.
Cane marl.......... 16 parts
Ball clay............ 12 parts
Feldspar........:. . . 8 parts
China clay.......... 6 parts
Flint............... 4 parts
Ball clay........... 22 parts
China clay......... 5.5 parts
Flint.............. 5 parts
Feldspar........... 3.5 parts
Cane marl......... 12 parts
Ball clay........... 120 parts
Ground ocher...... 120 parts
Ground manganese. 35 parts
Ball clay............ 12 parts
China clay.......... 10 parts
Feldspar............ 8 parts
Bull fire clay........ 16 parts
Yellow ocher........ 3 parts
Cane marl.......... 30 parts
Ball clay............ 10 parts
Stone.............. 7 parts
Feldspar............ 4 parts
Red marl........... 50 parts
China clay.......... 7 parts
Ground manganese .. 6 parts
Feldspar............ 3 parts
In making mazarine blue glazed bricks use the white body and stain the glaze only.
Mazarine blue....... 1 part
Glaze.............. 7 parts
For royal blue use 1 part stain to 6 parts white body, and glaze unstained.
Numerous brick manufacturers possess beds of clay from which good and sound bricks or tiles can be made, the only drawback being that the clay does not burn a good color. In many cases this arises from the fact that the clay contains more or less sulphur or other impurity, which spoils the external appearance of the finished article. The following stain will convert clay of any color into a rich, deep red, mixed in proportions of stain, 1 part, to clay, 60 parts.
Crocus martis....... 20 parts
Yellow ocher........ 4 parts
Sulphate of iron...... 10 parts
Red oxide of iron..... 2 parts
A still cheaper method is to put a slip or external coating upon the goods. The slip being quite opaque, effectively hides the natural color of the brick or tile upon which it may be used. The process is to mix:
Blood-red stain...... 1 part
Good red clay....... 6 parts
Add water until the mixture becomes about the consistency of cream, then with a sponge force the liquid two or three times through a very fine brass wire lawn, No. 80, and dip the goods in the liquid as soon as they are pressed or molded.
 
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