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.
For "Valve-Oleum" cylinder oil, a barrel of cylinder stock and from 40 to 50 gallons of degras are used at the boiling with the compound, if the cylinder stock to be used is of a reasonable cold test, otherwise a barrel of 25° paraffine oil is used. The batch is then finished up with from 40 to 45 barrels of filtered cylinder stock, which has also to be previously heated until all hygroscopic moisture and arising scum have been removed, as otherwise the combination will not remain uniform. Imitations of the "Valve-Oleum" oils for the sole purpose of giving to light distillates or poor paraffine oils some lubricating qualities, such as the so-called "Eldorado" oil and others, will easily thin out, separate and lose their consistency, as they are only crudely mixed with distillates or light paraffine oils not previously freed from their adhering hygroscopic moisture and light hydrocarbon vapors in suspension.
White "Valve-Oleum" castor oil is made precisely like the "Valve-Oleum" engine oil, but extra white winter-strained lard oil or prime white lard grease is used in the making of the oleate alumina compound, and 300° white mineral oil in place of the paraffine oil.
"Valve-Oleum" castoroleum, also known as "Commercial Castor Oil," a cheap substitute for castorbean oil, is made by using white tallow or prime white lard grease for making the alumina compound, adding some 300° F. white mineral oil, to be boiled with the alumina bath, and, after washing and roasting the alumina compound down to a perfectly clear and transparent product, it is mixed with white summer cottonseed oil, previously blown at a low temperature, to a consistency of about 15° to 18° Baume.
"Valve-Oleum" Linoleum is made by using linseed oil, fish oil, rapeseed oil or corn oil for making the alumina compound, boiling with an addition of neutral oil and mixing with linseed oil previously blown at a moderate heat to a consistency of about 18° Baume. In place of alum, acetate of lead can be used to precipitate the linoleate of soda, thereby forming a linoleate of lead.
The only notice accorded in recent years to the Valve-Oleum Oils is given in a German work on Petroleum Oils by Engler-Hoefer.* They are briefly mentioned as being oleates and palmitates of alumina and used to improve the viscosity of petroleum derivatives.
From observations made by the author in the sixties, his attention was drawn to the fact that the fatty oils were then alone in use for lubricating machinery and that their lighter compounds, the oleic acid and the palmitic acid, were the real factors in the lubricating process, leaving the heavier stearic acid, unable to vaporize by frictional heat, to accumulate as gummy deposits on the bearings and cylinder. He also noticed that the oils produced by distillation of the petroleum oils were exclusively operated on to obtain the more valuable crystalline wax they contain, and the remaining paraffine oil was used for lubricating, and he also observed that depriving the paraffine oils of their wax, they were also being deprived of their viscosity or adhesiveness, the property that holds the otherwise too fluid oil to the metals and allows its lighter constituents to do their work and evaporate with the absorbed frictional heat into space.
* "Das Erdoel," Leipzig, 1913.
To remedy this defect the paraffine oils were then compounded with additions of fatty oils, but it was soon found that the free fatty acids of which all fatty oils are composed acted injuriously on the metal of which machinery in constructed. The idea was then conceived to bind the fatty acids to neutral metallic bases, thereby making them innocuous and permitting their excellent clinging power as viscosity to be combined with the great diffusing power of the mineral oil, thus creating Valve-Oleum oils.
The following receipt from a German report is similar to Valve-Oleum Oils.
Precipitate an emulsion of wool-fat in soda lye with concentrated alum solution. The precipitate forms a brown, soft, spongy, sticky mass (aluminium lanolate) and is freed from salt and soap by pressing and washing with hot water. It is then dissolved in mineral oil. With 14 parts of mineral oil of 0.885 to 0.886 specific gravity 1 part of aluminium lanolate yields a lubricant of the viscosity of olive oil.