Part 11 (1/2)

Tallow 100 lbs.

Cochin Cocoanut Oil 100 ”

Castor Oil 60 ”

Glycerine 20 ”

Rosin, W. W. 20 ”

Sugar 40 ”

Water 50 ”

Soda Lye, 36 degs. B. 164 ”

Alcohol 8 gal.

V.

Tallow 174 lbs.

Cocoanut Oil 114 ”

Soda Lye, 38 degs. B. 170 ”

Sugar 80 ”

Water 72 ”

Alcohol 16 gal.

Rosin may be added in this formula up to 20 per cent. of fats used and the tallow cut down correspondingly.

SHAVING SOAPS.

The requirements of a shaving soap are somewhat different than those of other soaps. To be a good shaving soap the lather produced therefrom must be heavy, creamy, but not gummy, and remain moist when formed on the face. The soap itself should be of a soft consistency so as to readily adhere to the face when used in stick form. It should furthermore be neutral or nearly so to prevent the alkali from smarting during shaving.

Shaving soap is made in the form of a stick, and a tablet for use in the shaving mug. Some shavers prefer to have the soap as a powder or cream, which are claimed to be more convenient methods of shaving. While a liquid shaving soap is not as well known because it has not yet become popular, some soap for shaving is made in this form.

Formerly shaving soap was extensively made from a charge of about 80 parts tallow and 20 parts cocoanut oil as a boiled settled soap, but either making the strengthening change with potash lye or using potash lye in saponifying the stock and graining with salt. Soaps for shaving made in this manner are very unsatisfactory, as they do not produce a sufficiently thick or lasting lather and discolor very materially upon ageing. Pota.s.sium stearate forms an ideal lather for shaving, but readily hardens and hence needs some of the softer oils, or glycerine incorporated with it to form a satisfactory soap for shaving.

The selection of materials for making a shaving soap is important. The tallow used should be white and of high t.i.ter. Cochin cocoanut oil is to be preferred to the other kinds, and the alkalis should be the best for technical use that can be purchased--76 per cent. caustic soda and 88-92 per cent. caustic potash are suitable. By the use of stearic acid it is a simple matter to reach the neutral point which can be carefully approximated.

The following are shaving soap formulae which have been found to give good satisfaction:

I. lbs.

Tallow 360 Stearic acid 40 Soda lye, 41 B. 147 Potash lye, 34 B. 87 Water 32 Gum tragacanth 1

II. lbs.

Tallow 282 Cocoanut oil 60 Stearic acid 50 Bayberry wax 18 Soda lye, 41 B. 147 Potash lye, 34 B. 90 Water 32

III. lbs.

Tallow 400 Cocoanut oil 176 Stearic acid 415 Caustic soda, 40 B. 182 Caustic potash, 38 B. 108

To proceed, first run into the crutcher the tallow, cocoanut oil and bayberry wax when used, and bring the temperature of the ma.s.s up to 140-160 F. by dry steam. Then add the caustic soda lye and keep on heat with occasional mixing until it is all taken up. When this stage is reached gradually add all but about 5 per cent. of the potash lye, and complete the saponification. This point having been reached, the heat is turned off; the crutcher is run and the stearic acid, previously melted by dry steam in a lead-lined or enameled vessel, is run in in a continuous stream and the crutching continued for fifteen minutes to half an hour. Samples are taken at this time, cooled and tested by alcoholic phenolphthalein solution. If too alkaline more stearic acid is added, if too acid more potash lye from that previously reserved. After each addition of lye or stearic acid the ma.s.s is crutched from 10 to 15 minutes longer, another sample is taken, cooled and again tested. When the phenolphthalein shows a very light pink after several minutes, the soap is practically neutral, although at this point one can better judge by dissolving a sample in hot neutralized alcohol made by putting into the alcohol a few drops of phenolphthalein, and then adding weak alkali drop by drop from a burette until a slight pink, not yellow, tint is obtained, and noting the color of the solution. The solution should show a very light pink when the soap is properly neutralized. When this stage is arrived at the gum tragacanth, previously softened in water, is crutched in if it is to be added. The soap is then framed, stripped in three or four days, dried and milled.

The formulae as given are for shaving sticks, and do not readily press unless thoroughly dried. A more satisfactory result is obtained by adding at the mill 25 per cent. of white tallow base to obtain a satisfactory mug soap.

SHAVING POWDER.