Most greases for lubricating are made in the following manner: Common red rosin oil, say five hundred pounds, is heated for about one hour with about two pounds of calcium hydrate. It is then allowed to cool and is skimmed, and from ten to fifteen pounds of rosin oil-lime soap are slowly stirred in until the mixture assumes a buttery consistency. Lime soap is made by slowly heating and mixing 100 pounds of crude rosin oil with some 80 pounds of hydrate of lime, and boiling into a molasses-like consistency.

For rosin grease, lime paste is made by slaking say 10 pounds of quicklime with about 40 pounds of water; the whole is then passed through a sieve to separate all coarse particles, and to allow the fine lime-paste to settle. The water is then poured off and from 6 to 8 gallons of crude rosin oil are stirred into the lime-paste and allowed to stand for a few hours. All accumulated water is then drawn off and from 8 to 10 gallons of mineral or heavy petroleum oil are added. The whole is then heated to about 230° to 240° F., stirred and well mixed and allowed to cool and set to proper consistency.

A rosin grease, without heating, in the cold way, is made by mixing and stirring well together 20 gallons of crude paraffine or other mineral oil, in which some 80 pounds of rosin have previously been dissolved by heat, with a lime-paste made by slaking one-half to three-quarters of a bushel of lime, sifting it from all coarse particles and separating most of the water from it. It is stirred until a smooth, uniform consistency is obtained. From 3 to 5 gallons of crude rosin oil are then slowly added and stirred to a proper buttery consistency. The product of this process is the well known "Valve-Oleum Zola Axle Grease". Additions of fats or fatty oils improve its quality.

The following are some formulas after which nearly all grease lubricants are manufactured :

Half a pound of caustic soda is dissolved in one gallon of water; from three to five pounds of tallow and one-half to one gallon rosin oil are added, and the whole is heated to about 210° F. and well mixed, and then stirred, as it cools, to its proper consistency.

Forty gallons petroleum oil, fifty pounds of yellow grease or tallow and sixty pounds of rosin are heated together at a temperature of about 240° F. From two to two-and-a-half gallons of soda lye are then gradually added, and all is mixed and stirred well. When cold, in about twelve hours, it will be ready for use.

For a cup grease, seventy-five pounds of tallow, thirty to fifty pounds of rosin, some thirty to forty gallons of paraffine oil, and about ten to fifteen pounds of oleate of soda or common soap are melted together and stirred until a uniform and smooth buttery consistency is obtained.

Also : One part of tallow or yellow grease, four parts of cylinder stock or paraffine oil of a low gravity, and one-quarter part of caustic lye of from fifteen to twenty degrees Baume, are heated and stirred until cold and of proper consistency.

Dark Axle Grease: Thirty-five gallons West Virginia black oil, in which some fifty pounds of rosin have been dissolved by heat, and lime-paste from half a bushel of lime, are well stirred and brought to a proper consistency by the slow addition of from four to six gallons of crude rosin oil.

Linseed Oil Grease: One hundred pounds of tallow, one hundred pounds of rosin and ten to twelve gallons of linseed oil, with from six to eight gallons of caustic soda-lye of about five degrees Baume, are boiled together and allowed to cool and set to proper consistency.

One gallon petroleum oil, one-half pound tallow, one-half pound palm butter, one-half pound plumbago and one-quarter of a pound of soda are heated and kept for about an hour at a temperature of about 180° F., then allowed to cool down, and are stirred until well setting to consistency.

Or: Water, one gallon, one-half pound soda, three to five pounds of tallow, from six to ten pounds of palm oil and sufficient rosin to give the desired consistency, are heated to about 250° F., well stirred until cooled down to about 70° F., and allowed to set.

Or: Ten pounds of common soap well dried and cut in small pieces, from fifteen to twenty pounds of filtered cylinder stock and about fifteen pounds of heavy petroleum oil, are heated to about 230° to 240° F., and well stirred until all the soap is dissolved, and the whole is then allowed to cool to proper consistency.

Or: Palm oil, tallow, or tallow oil and soda, dissolved in as little water as possible, are heated and stirred into a uniform buttery mass.

Or: One gallon crude rosin oil, two to three pounds of quicklime slaked with about one gallon of water are mixed and allowed to settle and the adhering water drawn off. Heavy petroleum oil and from three to five pounds of graphite (plumbago) are then added, and all well mixed and stirred to a uniform and buttery consistency.

One per cent of castor oil soap will solidify paraffine oils in vacuum to a solid grease.

The manufacture of all greases is based on a semi-saponification of fatty matter. Below are given a number of formulas for the manufacture of grease as practised in Germany in latter years.

Palm Oil Grease

I. Melt together, tallow 150 parts, palm oil 100, soda 25, water 160.

II. Tallow 100 parts, palm oil 160, soda 35, water 300.

III. Rosin 100 lbs., palm oil 6 1/2 lbs., refined rosin oil 18| lbs., soda lye of 22° Be. 24 1/2 lbs., water 2 lbs. Melt the rosin in an iron kettle over a moderate fire and saponify it by adding the caustic soda lye and the water. The melted palm oil together with the rosin oil is then brought into the kettle and by crutching combined with the saponified rosin. Stirring is then continued till the mass is of uniform consistency.

Yellow Axle Grease

American rosin 100 lbs., caustic soda lye of 20° Be. 12 1/2 lbs., crude rosin oil 12 1/2- lbs. Melt the rosin in an iron kettle, then add gradually the soda lye, and finally, whilst stirring vigorously, the rosin oil.

Axle Grease Prepared In The Cold Way

The process of the production of this grease is based upon the property of rosin oil to saponify with ease . when mixed with slaked lime in the form of powder. The lime used must be fat and contain up from 96 to 98 per cent, calcium hydrate. A content of 5 to 8 per cent, of magnesia in the lime is a drawback to saponification, small dull globules of fat being segregated. Saponification is most readily effected at 64° to 68° F.

I. Blue mineral oil 70 per cent., slaked lime 10 per cent., rosin oil 15 per cent.

II. Blue mineral oil 60 per cent., slaked lime 9 per cent., gypsum 18 per cent., rosin oil 13 per cent.

III. Blue mineral oil 36 per cent., naptha residue 36 per cent., slaked lime 11.5 per cent, rosin oil 15.5 per cent.

IV. Blue mineral oil 20 per cent., gypsum 40 per cent., rosin oil 8.5 per cent., lime 8.5 per cent.

Bring the mineral oil and the very dry slaked lime into a vat and after mixing for half an hour pass the mixture through a hair-sieve (25 to 30 meshes to the square centimeter) into another vessel, pressing through any particles of lime. Then add the naphtha and other ingredients and stir thoroughly. Finally add the rosin oil and knead the whole to a butyraceous mass.