To Deodorize Putrid Fish Oil.—For each 100 pounds of oil, pulverize 1 pound of chloride of lime; rub to a stiff paste with a little cold water, and thin to the consistency of cream. Pour the oil into a lead-lined vat, stir in the chloride of lime, and let stand 3 or 4 hours, stirring frequently. Add 1 pound of sulphuric acid di luted in 25 times its volume of water, and boil in an iron kettle on a slow fire, stirring constantly. When the mixture is perfectly liquid and falls in drops from the stirrer, return to the vat, and when the oil has separat ed, draw off the water by means of a spigot.
To Preserve Animal Oils. — Add 1 dram of powdered slippery-elm bark to each pound of oil, and heat gently over a slow fire. When the bark set tles, strain off the fat. This gives an agreeable odor to the oil and pre vents it from becoming rancid, To Restore Rancid Animal Oils.— Put the oil in a suitable kettle over a slow fire, and stir in clean lumps or grains of charcoal from which the dust has been removed by winnowing with fans.
Or prepare double bags of flannel containing a layer of charcoal be tween, and filter the oil through these.
Neat's-foot Oil. — This is a coarse animal oil obtained by boiling neat's feet, tripe, etc., in water. It is very emollient and is much used to soften leather. In the commercial process the feet are heated with steam until the hair, wool, and dirt can be re moved, and afterwards boiled until the oil is extracted. The crude oil is of a grayish color, but when clarified by filtration is of a pale-lemon yellow. It is often adulterated.
To Purify Neat's-foot Oil. — Mix with gentle heat, stirring vigorously, equal parts of neat's-foot oil and rose water. When cool, the oil will rise to the surface and may be ladled off. Repeat if necessary. The refined oil is the basis of the best grades of cold cream.
Lubricants.—Lubricants are materi als used to lessen the friction of work ing parts of machinery. All of the animal and vegetable nondrying oils are suitable; also the mineral oils, as petroleum products; and plumbago, graphite, or black lead, which is the only solid lubricant in common use. These substances are often mixed for lubricating purposes. Sperm oil is the best of lubricants, but is too ex pensive for ordinary use. Lard oil is cheap and good. Neat's-foot oil is also used. Olive oil, colza, and rape-seed oils are suitable.
Lubricants for Heavy Pressure. Grind black lead with 4 times its weight of lard or tallow. Add, if de sired, 7 per cent of gum camphor. This was formerly a trade secret.
Or mix pule black lead with tal low.
Or mix tallow with red or white lead, or substitute lard for tallow.
Or add a portion of heavy mineral oil to any of the above, Axle Grease.—For axle grease, mix
3 pounds of tallow, 3 pounds of palm oil, pound of caustic soda, and 1 gallon or more of water. Melt to gether and evaporate the water with gentle heat, but do not let the mixture boil.
Or boil up together 20 ounces of palm oil with 28 ounces of tallow. Remove from the fire and stir con stantly until it cools to a blood heat. Strain through cheese cloth into a solution of 8 ounces of soda in 1 gill of water, mixing thoroughly. This mixture is suitable for summer heat. For cold weather, use 20 ounces of tal low to 28 ounces of palm oil. Or, for average temperatures, 20 ounces of each.
Lubricator for Drills. — For iron drills, use 4 ounces of soft soap to 1 quart of boiling water. This is cheap and effective.
Wood Lubricator.—Lubricate wood en bearings, as pulleys and the like, with common hard yellow soap or soft soap, taking care to evaporate with gentle heat any excess of water the latter may contain. Rub window casings, bureau drawers, and the like freely with hard yellow soap slightly moistened with water. This lubricates them permanently and prevents their sticking.
To Purify Lubricants.—The animal and vegetable oils of commerce, as neat's-foot oil, rape oil, and the like, often show traces of the acids used in purifying them, and these are likely to injure the works of clocks, watches, sewing machines, and other delicate machinery. Hence, to purify com mercial oils for such uses, put them in a vessel containing a quantity of rusty iron and let stand for a few days, then strain through silk or cot ton wool.
Or pour the best olive oil into a glass bottle, and add equal parts of zinc and lead shavings. Let stand in a cool place until the oil becomes transparent.
Or use lead shavings only and ex pose the oil to the sun for several weeks. A white precipitate will be formed, and the oil will become per fectly transparent. Strain through silk the pure liquor from the sedi ment and bottle for use. This oil will not injure the most delicate machin ery.
Oil for Whetstones.—Use kerosene oil on whetstones, oilstones, or for mixing other abrasives. It keeps the stone in good condition, and also as sists in the process of sharpening.
To Straighten Oilstones. — An oil stone, after having been used for some time, becomes concave and does not give a good edge. To face a worn oilstone, take a flat piece of iron or steel having a perfectly smooth face, back it with a wooden grip or handle, and rub down the face of the oilstone with a mixture of emery and powdered pumice stone in water. Finish with the finest emery or pumice and kero sene oil. This gives with very little effort a smooth, flat face.