This section is from the book "A Practical Treatise On Friction, Lubrication, Fats And Oils", by Emil F. Dieterichs. Also available from Amazon: A practical treatise on friction, lubrication, fats and oils.
The manufacture or compounding of lubricants is manifold. For cylinder oils, mineral or petroleum oils of a specific gravity of about 27° Baume and a fire test of about 550° F., either alone or with additions of from one to ten or fifteen per cent of animal or vegetable oils, are used. The fatty oils that such lubricants are generally compounded with are lard oil, neatsfoot oil, tallow oil, linseed oil, cottonseed oil, rapeseed oil, or degras. For heavy pressure and low-speed machinery, lard, tallow and other compounded greases, either by themselves or mixed with graphite (plumbago), mica and soapstone (talc), are used.
On account of their great propensity for absorbing oxygen, the fatty oils are now seldom used alone for lubricating, but are more or less compounded with petroleum oils. The viscosity of lubricating power of spindle oils and red oils depends on the amount of amorphous parraffine wax they hold in suspension, which, however, loses much of its consistency under the influence of frictional heat.
To give petroleum oils a viscous consistency they are often compounded with proportions of oleate of lead (lead plaster) dissolved in the oil while heated to from 140° to 160° F. One to two per cent of unvulcanized caoutchouc or rubber are also often dissolved in the oil, heated and stirred together until thoroughly diffused. Soap in various proportions and thoroughly dried is also compounded in petroleum lubricating oils by heating and stirring until fully dissolved and diffused and the oil has become perfectly bright and clear. Four ounces of soap to a gallon of oil will cause it to gelatinize at 60° F., and one pound of soap to the gallon will convert it into grease.
For cylinder oil, steam-refined residuum stock or medium filtered cylinder stock is heated to about 130° to 140° F. and stirred or blown until free from moisture and scum, and from one to five gallons, or even more, of tallow oil, lard oil, neatsfoot oil, rapeseed oil, olive oil, or fish oil added to each barrel of stock. To give common filtered stock a better cold test for winter use paraffine oil or red oil, of 28° to 30° Baume is added in the proportion of about five gallons, more or less, to a barrel of stock.
Degras (woolfat) is also used in the compounding of this kind of cylinder oils, in the proportion of from one to three gallons to a barrel of filtered stock. The degras should be previously heated and all arising scum removed before mixing with the cylinder stock.
Castorbean oil, well heated together with yellow lard grease, and combined with well heated cylinder stock, is compounded for cylinder lubricating oils.
For engine and machinery oil, paraffine, spindle or red oils of a gravity from 28° to 33° Baume, are compounded and well stirred together with a few gallons of filtered stock to improve the viscosity of the lighter petroleum oils.
The compounding of petroleum with fatty oils, for engine and machinery lubricating purposes, should always be conducted at a temperature of about 140° to 160° F. and with a thorough mixing, else the oils, being only a mechanical, and and not a chemical, mixture, when resting will separate from each other, on account of their differences in specific gravity. This explains the fact that such compounded oils, when imperfectly mixed, when kept in tanks and gradually drawn off by the faucet placed near the bottom, appear at first to be of a satisfactory consistency, but drawing towards the end are complained of as being too thin and deficient in body, the oil in the course of time having separated and the lighter oil having gradually risen to the top, 5 Crude rosin oils are refined by distillation and the resulting products are treated and bleached with chemicals and skillfully deodorized so that not the slightest odor would betray their origin, unless partially decomposed under application of heat. As the rosin oils are of a very low gravity, they are used in the compounding of lubricating oils to give the petroleum oils a body and to pass the lighter oils off for lubricating oils of lower gravity and greater viscosity. Lard oils and other fatty oils are often adulterated with petroleum oils, and to reduce the lighter gravity of the latter, have been compounded with such deodorized rosin oils, to equalize the specific gravity of such compounded oils to that of genuine lard oil.
Lubricating oils have also been made by avaricious and ignorant compounders by mixing heavy rosin oils with lighter petroleum oils or even simply dissolving common rosin in them, in the proportion of from two to four pounds to a gallon. The viscosity or body of such compounded oils appears deceptively superior to some of the best lubricating oils, but like all rosin oils and rosin and rosin-oil mixtures, which form resinous deposits under the influence of frictional heat or on exposure to the air, they are entirely unfit for lubricating purposes, as they gum up the machinery and retard the motion by their sticking propensities.
Receipts of Lubricants used in Germany. Cohesion oils. - A more or less viscous fat serves invariably as the basis of these oils. Rape oil is most frequently used, more seldom train oil, and, to decrease the degree of fluidity, tallow, palm oil, neatsfoot oil, or another solid fat is generally added. Besides these fats all these oils contain rosin oil in varying quantities, from 8 to 20 per cent of the amount of fat used. The peculiarly characteristic viscosity of these oils is imparted to them by the addition of up to 15 per cent of the fat used of American rosin. The larger the quantity of the latter, the greater the cohesion of the lubricant will be. It is, however, not advisable to use more than 15 per cent, of rosin, especially if the lubricant is to be used also at a lower temperature. Some cohesion oils contain coloring or odoriferous substances, or both. As lubricants these substances are entirely indifferent, and are only added to cover the other constituents and render their detection more difficult.
The preparation of cohesion oils is quite simple. The rape oil is slightly heated in a kettle and the determined quantity of solid fats (tallow, palm oil, etc.) is added. In another kettle which must be especially protected to prevent ignition of the contents, the rosin oil is heated almost up to the boiling point and the rosin, previously broken into small pieces, is gradually added, a fresh portion of it being thrown in only after the one previously introduced is completely dissolved. To prevent the rosin from burning to the bottom of the kettle, solution should be assisted by stirring. When all the rosin has been dissolved in the rosin oil, the solution is ladled, whilst stirring constantly, into the kettle containing the oil and fat mixture, stirring being continued until the mass begins to get viscous.
Crude rape oil 190 parts, purified tallow 10 parts, rosin oil 20 parts, American rosin 24 parts.
Crude rape oil 192 parts, purified tallow 8 parts, rosin oil 16 parts, American rosin 16 parts.
Lubricants for Threshing Machines consist of mixtures of mineral oil with refined rape oil, for instance, 400 parts by weight of mineral oil of 0.906 to 0.908 specific gravity and 50 parts by weight of rape oil.
I. Refined rape oil 5 parts by weight, neatsfoot oil 5, white vaseline oil 3.
II. Refined rape oil 2 parts by weight, white vaseline oil 6.
Melt the solid constituents, then add the oil and mix thoroughly.
I. Melting point 120° F. - Tallow 1/2 part, cer-esin 1/2 part, filtered cylinder oil 4 parts,
II. Melting point 150° F. - Ceresin 1 part, tallow 1/2 part, filtered cylinder oil 1 1/2 parts, mineral oil of 0.903 to 0.907 specific gravity, 2 parts.
III. Melting point 184° F. - Cosmos cylinder oil 2 parts, cotton oil 1 part, oleic acid 1 part, ceresin 1 part.
IV. Melting point 215° F. - Petroleum jelly 1 1/2 parts, castor oil 1 part, aluminium oleate 1 part, ceresin 1 1/2 parts.
V. Melting point 220° F. - Petroleum jelly 1 part, seal oil 1 part, ceresin 1 1/2 parts.
I. Mix intimately 10 parts by weight of pure neatsfoot oil with 190 parts by weight of white vaseline oil.
II. Refined rape oil 25 parts by weight, white vaseline oil 15 parts by weight.
III. Refined rape oil 10 parts by weight, white vaseline oil 100 parts by weight.
Mix 127.5 parts by weight of machine oil of 0.915 specific gravity with 22.5 parts by weight of rosin oil.
Lubricant for Compressors consists of a mixture of 30 parts by weight of refined rosin oil and 170 parts by weight of mineral oil of 0.912 to 0.915 specific gravity.
I. Refined rosin oil 100 lbs., yellow rosin oil 600 lbs., rape oil 100 lbs.
II. Refined rosin oil 400 lbs., pale paraffine oil 300 lbs., cotton oil 300 lbs.
III. Refined rosin oil 100 lbs., pale rosin oil 300 lbs., cotton oil 120 lbs.
IV. Refined rosin oil 200 lbs., olive oil 100 lbs., rape oil 150 lbs., rosin oil 200 lbs.
Rapeseed oil, cottonseed oil and other fatty oils can be thickened and their viscosity increased by heating them to from 160° to 170° F. and forcing or blowing air heated to a like temperature through the oil for several hours. The propensity of the fatty oils for absorbing oxygen allows of turning them by this process into heavy, viscous oils, which are largely used to impart greater viscosity to lighter petroleum oils used for lubricating purposes.
Blown rapeseed oil has a specific gravity of 0.967 at 60° F., or 15° Baume.
Blown cottonseed oil has a specific gravity of 0.974 at 60° F., or 14° Baume.