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Home > of this peculiarity, which is...
Previous Next The best candle and soap tips online! of this peculiarity, which is by no means desirable, 5 per cent. of the soda is substituted by potash, which makes it more plastic. We submit a few of the combinations in vogue for palm soap. 35 parts. 35 " 30 " 60 parts. 20 " 20 " Palm oil . . Cotton-seed oil Pure tallow . Palm oil . . Tallow . . Cocoa-nut oil. Palm oil .... 50 parts. Tallow .... 30 " Resin 20 " 40 parts. 30 " 30 " Palm oil . . Tallow . . Cocoa-nut oil ROSIN SOAP. (YELLOW SOAP.) Rosin in soap may be styled an ameliorator, for, though in itself it will not form with alkali a useful soap, yet combined with fats, or when saponified added to other soaps made with the fatty bodies, it counts as so much grease, and contributes the popular qualities of being readily soluble and forming a copious lather when used for laundry and other domestic purposes. The methods for forming this soap are various: Either the rosin is saponified separately, or it is melted with the grease and boiled with the lyes. The latter is the usual mode in England, where is also added to the better qualities of rosin soaps a portion of palm oil, which tends to improve both their odor and color. Rosins in the United States are usually prepared for the soap boiler at the place of their production, and are of different qualities depending upon their color; of course the lighter and clearer in color the rosin is the better will be the quality and appearance of the soap. Yet it may be that the rosin at hand is dark and contains many impurities. If so, it is necessary to submit it to a purification, which is usually done by boiling it with a solution of common salt, when the impurities and much of its color are precipitated with the salt water. This is often repeated a second or a third time to insure a bright color. 287 286 TECHNICAL TREATISE ON SOAP AND CANDLES. Cocoa-nut oil is often added to rosin soaps, and is said to simplify the process and take less boiling; this oil moreover making the soap more solid. The usual formula is:— Palm oil 20 parts. Cocoa-nut oil 20 " Tallow " 30 " Rosin " 30 " The usual method used in England is, to charge the pan with 2000 pounds of tallow or soap grease, about 600 pounds of rosin, and 150 to 175 gallons of soda lye marking 10° to 20° B.; and, when the whole is melted and thoroughly combined, heat up the mixture to ebullition, being careful to stir all the while to prevent the adherence of the rosin to the bottom and sides of the pan. If the mass seems disposed to intumesce or swell, the fire must be lessened. This boiling should continue but two or three hours, because of the facility with which the union of the fat and alkali is effected. After six hours' repose, the exhausted lye is drawn off, and fresh is substituted, and the whole is again boiled for three hours more. Another repose of six hours is allowed, and the spent lye is again drawn off and renewed by fresh additions ; the boilings are thus continued until the soap shall have acquired consistency—a fact determined by taking a sample, and when cool, squeezing it between the thumb and finger. If hard, thin scales are formed, it is finished, or nearly so; if greasy, clammy, and soft, it is, on the contrary, not perfect, and must have more lye, and another boiling. In the first case, give a brisk boiling to the paste, and then put out the fire. Cool the soap by adding three buckets of weak lye, and two hours after, draw off the sub-lye. Next throw in six or eight buckets of water and boil briskly, stirring the mixture until the soap is melted; then, with a wooden spatula, take a little of the boiling paste, hold it up and observe whether it runs from the lye clear; if it does, add water to the pan, and continue the boiling. If it does not run from the lye, too much water has been added already, and there must then THE FABRICATION OF SOAPS. be poured in half a bucketful of strong solution of common salt. The most delicate part of the operation is that of finishing or fitting, and should, therefore, command the particular attention of the workman. If the fitting is perfect, the soap will, when the spatula is held obliquely,not run off", but shake and disperse' tremulously like jelly. It is then that the fire may be withdrawn, and the soap be regarded as finished. If it is desired to give a better color to this soap, about 20 pounds of palm oil may be added before finishing; and after two days it must be run into the frames, whence, after a week or less, it should be taken and cut into bars. When cocoa-nut oil is added, it is best to saponify separately with a strong lye, and add at the finish. By a still more simple process, the English now prepare this soap as rapidly as economically. Take- . 800 pounds. . 200 " . 400 " . 175 gallons. White tallow Palm oil .... Powdered rosin . Caustic lye of soda ash at 25° The whole is introduced into a large Papin's digester, and the mixture submitted for one hour to ebullition under pressure, at a temperature of 122.2° C. (252° F.). After this time the soap is finished and run into the frames. This seems to be all that is necessary to say about these-useful soaps. Of course if a soap is wanted by the old methods, we can but refer to the tallow soap, adding the rosin soap which has been made separately. RESINOUS GRAIN SOAP AND TURPENTINE SOAP. The first is a dark brown soap, which with 100 parts fat are combined 80 to 90 parts brown rosin. Turpentine soap possesses a light-yellow color, and is obtained by saponifying 100 parts of fat with 25 to 30 parts light rosin. For the fat sometimes tallow or palm oil alone is used, or in connection with olein, i. e., oleic acid. In the latter case an 288 Previous Next
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