A hand paste is usually made by merely dissolving ordinary tallow base in two or three times its weight of hot water and mixing in the desired quantity of pumice or sand and in some instances adding a little glycerine to keep it soft or a solvent of some kind for grease. It may also be made by directly incorporating any of these in a potash soap.
A cold made or semi-boiled cocoanut or palm kernel oil soap is the base used to add the pumice or sand to in making a cake soap of this sort. The following formulae serve as a guide for these soaps.
| I. | ||
| Palm Kernel or Ceylon Cocoanut Oil | 705 | lbs. |
| Pumice (Powdered) | 281 | " |
| Soda Lye, 38° B. | 378 | " |
| II. | ||
| Cocoanut Oil | 100 | " |
| Soda Lye, 38° B. | 55 | " |
| Water | 6 | " |
| Silver Sand (fine) | 60 | " |
To proceed place the oil in a crutcher and heat to 140° F. Sift in the pumice and mix thoroughly. The lye is then added which causes a curdling of the grain. The stirring is continued until the grain closes and the soap is smooth, after which the desired perfume is added and the soap dropped into a frame and crutched by hand. When the soap is set, it is slabbed, cut into cakes, dried slightly and pressed.
LIQUID SOAPS.
Liquid soaps are merely solutions of a potash soap, usually cocoanut oil soap, although corn oil is used to make a cheap soap. One of the difficulties encountered in liquid soap is to keep it clear. At a low temperature a sediment is often formed, but this can be overcome by the use of sugar and filtering the soap through a filter press at a low temperature. In order to prevent the soap from freezing, it is necessary to lower the freezing point by the addition of glycerine or alcohol.
To make liquid soap by any of the formulae given below, the oil is first run into a jacketed kettle with a stirring device, and heated to about 120° F. The potash lye is then added and the oil saponified. When the saponification takes place, especially when cocoanut oil is used, the mass swells rapidly and may foam over the sides of the kettle unless water is used to check this, or a kettle of about four to five times the capacity of the total charge of soap is used. When the saponification has occurred, the sugar, borax and glycerine are added, the water run in and the mixture stirred until the soap is thoroughly dissolved. Heat aids materially in dissolving the soap. The soap is then allowed to cool and if color or perfume is to be added this is stirred in, after which the soap is cooled and filtered or else run directly into barrels.
Tallow is not suitable for making a clear liquid soap since it is too high in stearine which when formed into the stearate makes an opaque solution. The formulae herewith given have been found to give good practical results.
| I. | lbs. |
| Cocoanut oil | 130 |
| Caustic potash lye, 28° B. | 135 |
| Sugar | 72 |
| Borax | 2 |
| Water | 267 |
| II. | lbs. |
| Corn oil | 130 |
| Caustic potash lye, 26° B. | 135 |
| Sugar | 72 |
| Borax | 2 |
| Water | 267 |
| III. | lbs. |
| Cocoanut oil | 100 |
| Caustic potash lye, 28° B. | 102 |
| Glycerine | 100 |
| Sugar | 70 |
| Water | 833 |