Part 319

«Galvanized Iron.»—For galvanized iron there has been recommended a wash consisting simply of dilute hydrochloric acid, which produces chloride of zinc, that in combination with the oxygen of the air is said to produce a film upon which oil color takes as good a hold as it would upon ordinary sheet iron.

Another method which has been tested and found effective is to make a solution as follows: One ounce of chloride of copper; 1 ounce nitrate of copper; 1 ounce sal ammoniac, dissolved in 2 quarts of soft water, to which is added 1 ounce of crude or commercial hydrochloric acid. This solution should be made in an earthenware dish or pot, or in glass or stoneware, as tin will precipitate the copper salts and make the solution imperfect. To large surfaces this solution is applied with a broad brush, when the surface assumes a deep black color, which in drying out in from 12 to 24 hours becomes a gray white, upon which the properly prepared primer will take a permanent grip. On the film so produced a much thinner paint will cover very much better than a stouter paint would on the untreated galvanized or ordinary iron surface. A single trial will convince the craftsman that this treatment is a method that will give lasting results, provided he tries the same priming paint on the treated and untreated surface.

«To Paint Wrought Iron with Graphite.»—In order to make wrought iron look like new mix fine graphite with equal parts of varnish and turpentine oil, adding a little siccative. Paint the iron parts with this twice, allowing to dry each time. Especially the second coating must be perfectly dry before further treatment. The latter consists in preparing graphite with spirit and applying it very thinly over the first coat. After the drying or evaporation of the spirit the graphite last applied is brushed vigorously, whereby a handsome, durable gloss is produced.

«Paint for Iron Bodies Exposed to Heat.»—Dilute 1 part soda water glass with 2 parts water and mix intimately with the following pigments:

White.—White lead or sulphate of barium.

Yellow.—Chromate of barium, ocher, or uranium yellow.

Green.—Chromic oxide or ultramarine green.

Blue.—Ultramarine.

Brown.—Oxide of cadmium, oxide of manganese or terra di sienna.

Red.—English red or chrome red.

Bronze powder in a suitable quantity may be added to the mixture, but not more paint should be prepared than can be used up in a few hours. The bronze powder may also be strewn on the fresh paint, or applied with a dry brush, to enhance the gloss. This paint is not affected by heat, and is inodorous.

«Protective Coating for Bright Iron Articles.»—Zinc white, 30 parts; {497} lampblack, 2 parts; tallow, 7 parts; vaseline, 1 part; olive oil, 3 parts; varnish, 1 part. Boil together 1⁠/⁠4 hour and add 1⁠/⁠2 part of benzine and 1⁠/⁠4 part of turpentine, stirring the mass carefully and boiling for some time. The finished paste-like substance can be readily removed with a rag without the use of solvents.

«Rust Paints.»—I.—A new rust paint is produced by the following process: Mix 100 parts dry iron sulphate and 87 parts sodium chlorate and heat to 1,500° to 1,800° F. The chlorine set free seems to have a very favorable action on the color of the simultaneously forming iron oxide. In order to avoid, however, too far-reaching an effect of the chlorine gas, about 18 pounds of a substance which absorbs the same mechanically, such as kaolin, ground pumice stone, ocher, etc., are added to the mixture.

II.—A material known under the names of lardite, steatite, agalmatolite, pagodite, is excellently adapted as a substitute for the ordinary metallic protective agent of the pigments and has the property of protecting iron from rust in an effective manner. In China, lardite is used for protecting edifices of sandstone, which crumbles under the action of the atmosphere. Likewise a thin layer of powdered steatite, applied in the form of paint, has been found valuable there as a protector against the decay of obelisks, statues, etc. Lardite, besides, possesses the quality of being exceedingly fine-grained, which renders this material valuable for use in ship painting. Ground steatite is one of the finest materials which can be produced, and no other so quickly and firmly adheres to the fibers of iron and steel. Furthermore, steatite is lighter than metallic covering agents, and covers, mixed in paint, a larger surface than zinc white, red lead, or iron oxide. Steatite as it occurs in Switzerland is used there and in the Tyrol for stoves, since it is fireproof.

«Steel.»—An excellent coating for steel, imitating the blue color of natural steel, is composed of white shellac, 5 parts; borax, 1 part; alcohol, 5 parts; water, 4 parts; and a sufficient quantity of methylene blue. The borax is dissolved in water, the shellac in alcohol. The aqueous solution of the borax is heated to a boil and the alcoholic solution of the shellac is added with constant stirring. Next add the blue color, continuing to stir. Before this coating is applied to the steel, e. g., the spokes of a bicycle, the latter are first rubbed off with fine emery paper. The coat is put on with a soft rag. The quantity of pigment to be added is very small. By varying the quantity a paler or darker coloring of the steel can be produced.

«PAINTS FOR ROOFS AND ROOF PAPER:»

«Carbolineum.»—This German preparation is made in three colors.

I.—Pale.—Melt together in an iron kettle, over a naked fire, 30 parts of American rosin F and 150 parts of pale paraffine oil and stir in 10 parts of single rectified rosin oil.

II.—Dark.—Melt 100 parts of anthracene oil and 20 parts of American rosin F on a slow fire. Next stir in 2 parts of Para rubber solution (or solution of caoutchouc waste) and keep on boiling until all is dissolved. When this is done there should be still added 5 parts of crude concentrated carbolic acid and 5 parts of zinc chloride lye, 50° Bé., stirring until cool. The last-named admixture is not absolutely necessary, but highly advisable, owing to its extraordinary preservative and bactericidal properties.

III.—Colored.—For red, melt 100 parts of coal-tar oil, then stir in 50 parts of pale paraffine oil, and finally 75 parts of bole or iron minium, and pass through the paint mill. Although the addition of iron minium is very desirable, it is considerably more expensive. For gray, proceed as above, with the exception that metallic gray is used in place of the bole. For green, metallic green is employed. The colors are identical with those used in the manufacture of roof varnish. To increase the antiseptic properties of the colored carbolineum, any desired additions of phenol or zinc chloride solutions may be made, but the chief requirement in the case of colored carbolineum is good covering power of the coating.

«Paints for Roofs Covered with Tar Paper, for Roofing Paper, etc.»—

I.—Distilled coal tar 70 parts Heavy mineral oil (lubricating oil) 10 parts American rosin 20 parts

II.—Distilled coal tar 50 parts Trinidad asphalt 15 parts Mineral oil, containing paraffine 10 parts Dry clay, finely ground 25 parts

«Imitation Oil Paint.»—Schulz’s German patent paint is cheap, and claimed to be {498} durable, weatherproof, and glossy, like oil paint. The application consists of a ground coat, upon which the surface coat proper is applied after the former is dry. For the preparation of the grounding dissolve 1,000 parts, by weight, of Marseilles soap in 10,000 parts of boiling water and stir. In a separate vessel dissolve 2,000 parts of glue in 10,000 parts of boiling water, adding 17,500 parts of spirit of sal ammoniac. These two solutions are poured together and well stirred. Then dissolve 400 parts of chrome alum in 5,000 parts of water, and pour into the above mixture. To this mixture add 10,000 parts of pipe clay, stirring the whole well and tinting with earth colors, ocher, Vandyke brown, etc. The solid ingredients must be dissolved in boiling hot water, and sifted so as to obtain a finely divided ground color. This priming is applied in a warm state. The coating proper is put on the ground coat after it is dry, in about one-half to one hour. For this coat dissolve 2,000 parts of crystallized alum in 10,000 parts of boiling water and add to this liquid a solution of 2,000 parts of glue in 10,000 parts of water; in a special vessel prepare soapsuds of 1,000 parts of Marseilles soap in 12,000 parts of boiling water; dissolve 120 parts of chrome alum in 1,500 parts of boiling water, and mix the three solutions together with diligent stirring. This paint or liquid should also be put on hot, and assures a durable exterior paint.

«PAINTS, STAINS, ETC., FOR SHIPS.»

«Anti-Fouling Composition.»—Make an agglutinant by heating together

By weight White lead, ground in oil 2 parts Red lead, dry 1 part Raw linseed oil 14 parts

While hot stir in yellow ocher, kaolin, baked clay in powder, or any inert body, such as silica, barytes, gypsum, etc., to form a stiff dough, and, without allowing this compound to become cold (the vessel should not be removed from the source of heat), dilute with more or less manganese linoleate to the required consistency.