Henley's Twentieth Century Formulas, Recipes and Processes. Various

which quickly {33} solidifies, for gas and wood distillation retorts, etc., and similar places where quickness of setting is requisite. It is more often, however, used with some fibrous material to give it greater strength. Asbestos is the most commonly used material of these, as it will stand a high temperature. When that is not so important, straw, plush trimmings, hair, etc., are used as binders, while broken stone, glass, and various mineral substances are used as fillers, but they do not add anything to the strength. These lutes seem to be particularly suitable for oil vapors and hydrocarbon gases.

       Formulas:(1) Plaster and water.(2) Plaster (wet) and asbestos.(3) Plaster (wet) and straw.(4) Plaster (wet) and plush trimmings.(5) Plaster (wet) and hair.(6) Plaster (wet) and broken stone, etc.

      II. Hydraulic Cement.—Cement is used either alone or with sand, asbestos, etc. These lutes are suitable for nitric acid. When used with substances such as rosin or sulphur, cement is probably employed because it is in such a fine state of division and used as a filler and not because of any powers of setting by hydration.

       Formulas:(1) Cement—neat.(2) Cement and asbestos.(3) Cement and sand.

      III. Clay.—This most frequently enters into the composition of lutes as a filler, but even then the very finely divided condition of certain grades renders it valuable, as it gives body to a liquid, such as linseed oil, which, unless stiffened, would be pervious to a gas, the clay in all cases being neutral. Thus, for luting pipes carrying chlorine, a stiff paste of clay and molasses has been suggested by Theo. Köller in Die Surrogate, but it soon gives way.

       Formulas:(1) Clay and linseed oil.(2) Same, using fire clay.(3) Clay and molasses.

      (1) Is suitable for steam, etc.; (2) for chlorine, and (3) for oil vapors.

      IV. Lime is used in the old lute known as putty, which consists of caustic lime and linseed oil. Frequently the lime is replaced by chalk and china clay, but the lime should be, in part at least, caustic, so as to form a certain amount of lime soap. Lime is also used in silicate and casein compositions, which are very strong and useful, but will be described elsewhere.

       Formulas:(1) Lime and boiled oil to stiff mass.(2) Clay, etc., boiled oil to stiff mass.

      V. Asphalt and Pitch.—These substances are used in lutes somewhat interchangeably. As a rule, pitch makes the stronger lutes. Tar is sometimes used, but, because of the light oils and, frequently, water contained, it is not so good as either of the others.

      Asphalt dissolved in benzol is very useful for uniting glass for photographic, microscopical, and other uses. Also for coating wood, concrete, etc., where the melted asphalt would be too thick to cover well. Benzol is the cheapest solvent that is satisfactory for this purpose, as the only one that is cheaper would be a petroleum naphtha, which does not dissolve all the constituents of the asphalt. For waterproofing wood, brick, concrete, etc., melted asphalt alone is much used, but when a little paraffine is added, it improves its waterproofing qualities, and in particular cases boiled oil is also added to advantage.

      Formulas:

1.	Refined lake asphalt.
2.	Asphalt	4 parts
Paraffine	1 part
3.	Asphalt	10 parts
Paraffine	2 parts
Boiled oil	1 part

      Any of these may be thinned with hot benzol or toluol. Toluol is less volatile than benzol and about as cheap, if not cheaper, the straw-colored grades being about 24 cents per gallon.

      Examples of so-called “stone cement” are:

4.	Pitch	8 parts
Rosin	6 parts
Wax	1 part
Plaster	1/4 to 1/2 part
5.	Pitch	8 parts
Rosin	7 parts
Sulphur	2 parts
Stone powder	1 part

      These compositions are used to unite slate slabs and stoneware for domestic, engineering, and chemical purposes. Various rosin and pitch mixtures are used for these purposes, and the proportions of these two ingredients are determined by the consistency desired. Sulphur and stone powder are added to prevent the formation of cracks, sulphur acting chemically and stone powder mechanically. {34} Where the lute would come in contact with acid or vapors of the same, limestone should not be the powder used, otherwise it is about the best. Wax is a useful ingredient to keep the composition from getting brittle with age.

      A class of lutes under this general grouping that are much used are so-called “marine glues” (q. v.). They must be tough and elastic. When used for calking on a vessel they must expand and contract with the temperature and not crack or come loose.

      Formulas:

6.	Pitch	3 parts
Shellac	2 parts
Pure crude rubber	1 part
7.	Pitch	1 part
Shellac	1 part
Rubber substitute	1 part

      These are used by melting over a burner.

      VI. Rosin, Shellac, and Wax.—A strong cement, used as a stone cement, is:

1.	Rosin	8 parts
Wax	1 part
Turpentine	1 part

      It has little or no body, and is used in thin layers.

      For nitric and hydrochloric acid vapors:

2.	Rosin	1 part
Sulphur	1 part
Fire clay	2 parts

      Sulphur gives great hardness and permanency to rosin lutes, but this composition is somewhat brittle.

      Good waterproof lutes of this class are:

3.	Rosin	1 part
Wax	1 part
Powdered stone	2 parts
4.	Shellac	5 parts
Wax	1 part
Turpentine	1 part
Chalk, etc.	8 to 10 parts

      For a soft air-tight paste for ground-glass surfaces:

5.	Wax	1 part
Vaseline	1 part

      6. A strong cement, without body, for metals (other than copper or alloys of same), porcelain, and glass is made by letting 1 part of finely powdered shellac stand with 10 parts of ammonia water until solution is effected.

      VII. Rubber.—Because of its toughness, elasticity, and resistance to alterative influences, rubber is a very useful constituent in lutes, but its price makes its use very limited.

      Leather Cement.

1.	Asphalt	1 part
Rosin	1 part
Gutta percha	4 parts
Carbon disulphide	20 parts

      To stand acid vapors:

2.	Rubber	1 part
Linseed oil	3 parts
Fire clay	3 parts

      3. Plain Rubber Cement.—Cut the crude rubber in small pieces and then add the solvent. Carbon disulphide is the best, benzol good and much cheaper, but gasoline is probably most extensively used because of its cheapness.

      4. To make corks and wood impervious to steam and water, soak them in a rubber solution as above; if it is desired to protect them from oil vapors, use glue composition. (See Section IX.)

      VIII. Linseed Oil.—This is one of the most generally useful substances we have for luting purposes, if absorbed by a porous substance that is inert.

      Formulas: 1. China clay of general utility for aqueous vapors.

      Linseed oil of general utility for aqueous vapors.

      2. Lime forming the well-known putty.

      Linseed oil forming the well-known putty.

      3. Red