Part 90

«Paint Deadening.»—In order to obtain an even dullness of large walls, proceed as follows: After all the dirt has been carefully swept off, oil with 2 parts linseed oil and 1 part turpentine and rub down the smooth places in the wet oil with pumice stone. When the oil coating is dry, mix the ground paint, consisting of whiting, 2 parts; and white lead, 1 part; both finely ground and diluted as above. Do not apply the grounding too thin, because the chalk in itself possesses little covering power. It is not the mission of the chalk, however, to adulterate the material, but to afford a hard foundation for the subsequent coats. For the third coating take white lead, 1 part; and zinc white, 1 part; thin as above and blend with a soft hair pencil. For the final application use only zinc white, ground stiff in oil with any desired mixing color and thinned with turpentine and rain water. Mix the {492} water and the turpentine with the color at the same time, and this coat may be dabbed instead of blended. By the addition of water the paint becomes dull more slowly and is a little more difficult to lay on; but it does not show a trace of gloss after a few days and never turns yellow, even in places less exposed to the air, and besides excels by great permanency.

Another way is to add white wax instead of water to the last coating. This wax paint also gives a handsome dullness but is more difficult of treatment. A nice matt coating is also obtained by addition of Venetian soap, dissolved in water instead of the wax. This is very desirable for church decorations where exceptionally large surfaces are to be deadened.

«PAINT DRYERS:»

I.—Ordinary barytes 25 pounds Whiting 4 pounds Litharge 2 pounds Sulphate of zinc 2 pounds Sugar of lead 2 pounds Boiled linseed oil 5 pounds Plaster of Paris 1⁠/⁠2 pound

II.—Whiting 16 pounds Barytes 16 pounds White lead 3 pounds Boiled linseed oil 3⁠/⁠4 gallon

«PAINTS FOR GOLD AND GILDING:»

«Gold Paints.»—The formulas of the various gold paints on the market are carefully guarded trade secrets. Essentially they consist of a bronze powder mixed with a varnish. The best bronze powder for the purpose is what is known in the trade as “French flake,” a deep gold bronze. This bronze, as seen under the microscope, consists of tiny flakes or spangles of the bronze metal. As each minute flake forms a facet for the reflection of color, the paint made with it is much more brilliant than that prepared from finely powdered bronze.

For making gold paint like the so-called “washable gold enamel” that is sold by the manufacturers at the present time, it is necessary to mix a celluloid varnish with the French flake bronze powder. This varnish is made by dissolving transparent celluloid in amyl acetate in the proportion of about 5 per cent of celluloid.

Transparent celluloid, finely shredded 1 ounce Acetone, sufficient quantity. Amyl acetate to make 20 ounces.

Digest the celluloid in the acetone until dissolved and add the amyl acetate. From 1 to 4 ounces of flake bronze is to be mixed with this quantity of varnish. For silver paint or “aluminum enamel,” flake aluminum bronze powder should be used in place of the gold. The celluloid varnish incloses the bronze particles in an impervious coating, air-tight and water-tight. As it contains nothing that will act upon the bronze, the latter retains its luster for a long period, until the varnished surface becomes worn or abraded and the bronze thus exposed to atmospheric action.

All of the “gold” or, more properly, gilt furniture that is sold so cheaply by the furniture and department stores is gilded with a paint of this kind, and for that reason such furniture can be offered at a moderate price. The finish is surprisingly durable, and in color and luster is a very close imitation of real gold-leaf work. This paint is also used on picture frames of cheap and medium grades, taking the place of gold leaf or the lacquered silver leaf formerly used on articles of the better grades; it is also substituted for “Dutch metal,” or imitation gold leaf, on the cheapest class of work.

A cheaper gold paint is made by using an inexpensive varnish composed of gutta percha, gum dammar, or some other varnish gum, dissolved in benzole, or in a mixture of benzole and benzine. The paints made with a celluloid-amyl-acetate varnish give off a strong banana-like odor when applied, and may be readily recognized by this characteristic.

The impalpably powdered bronzes are called “lining” bronzes. They are chiefly used for striping or lining by carriage painters; in bronzing gas fixtures and metal work; in fresco and other interior decoration, and in printing; the use of a very fine powder in inks or paints admits of the drawing or printing of very delicate lines.

Lining bronze is also used on picture frames or other plastic ornamental work. Mixed with a thin weak glue sizing it is applied over “burnishing clay,” and when dry is polished with agate burnishers. The object thus treated, after receiving a finishing coat of a thin transparent varnish, imitates very closely in appearance a piece of finely cast antique bronze. To add still more to this effect the burnishing clay is colored the greenish black that is seen in the deep parts of real antique bronzes, and the bronze powder, mixed with size, is applied only to the most prominent parts or “high lights” of the ornament. {493}

Since the discovery of the celluloid-amyl-acetate varnish, or bronze liquid, and its preservative properties on bronze powders, manufacturers have discontinued the use of liquids containing oils, turpentine, or gums, since their constituents corrode the bronze metal, causing the paint finally to turn black.

«Gilding in Size.»—The old painters and gilders used to prepare the gold size themselves, but nowadays it is usually bought ready made, barring the white of egg additional. The best and most reliable, and especially suited for fine work, is undoubtedly the red French gold size. It is cleaned, as far as possible, of all impurities, and powdered. For 246 grains take 1 white of egg; put it into a glass, taking care to exclude the yolk entirely—otherwise the burnish will show black spots. Beat the white of egg to a froth with a long, well-cleaned bristle brush; add the froth to the size and grind finely together, which is soon done. When grinding, a little water and red size, if necessary, may be added (use only water for thinning). After being ground, the size is forced through a very fine hair sieve into a perfectly clean vessel, and covered up well, for immediate or subsequent use.

The raw stuff of the red size is bolus, which is dug in France and Armenia in excellent quality. Besides the red size there are yellow, white (pipe clay), blue, and gray (alumina), which are used for certain purposes, to enumerate which here would lead too far.

For burnish gold, always take yellow size for ground work. Dip a finely ground bristle brush in the gold size prepared for use; fill a well-cleaned glass (holding 1 pint) half full of water, and add the size contained in the brush, also about 4 to 5 spoonfuls of pure alcohol. It is advisable not to take too much size; the liquid, when applied, must hardly have a yellow tint. When this is dry soon after, commence applying the size, for which a hair pencil is used. The essentials are to paint evenly and not too thickly, so that the tone remains uniform. Apply three coats of size.

When the size is laid on correctly and has become dry, brush the whole with a special brush, or rub with a flannel rag, so as to obtain the highest possible luster. The size must not stand too long; otherwise no gloss can be developed. After brushing, coat the work with weak glue water and wrap it up in tissue paper if the gilding is not to be done at once.

The strictest cleanliness is essential, as the red gold size is very sensitive. The parts where the size has been applied must not be touched with the hand, else grease spots will ensue, which will make a flawless gloss in gilding impossible. The least relaxation of the necessary attention may spoil the whole job, so that everything has to be ground off again.

The necessary tools for the application of gold leaf are: Hair pencils of various sizes, tip, cushion, and gilding knife, as with oil-gilding. Take pure alcohol or grain brandy, and dilute with two-thirds water. When ready to apply the gold leaf, dip a hair pencil of suitable size into the fluid, but do not have it full enough that the alcohol will run on the size ground. Moisten a portion of the ground surface as large as the gold leaf, which is laid on immediately after. Proceed in the same manner, first moistening, then applying the ready-cut gold leaf. The latter must not be pressed on, but merely laid down lightly, one leaf a little over the edge of the previous one, without using up too much gold. Technical practice in gold-leaf gilding is presupposed; through this alone can any skill be acquired, reading being of no avail.

The leaf of gold being applied, all dust must be swept off by means of a light, fine hair pencil (but never against the overlapping edges), and the burnishing is commenced. For this purpose there are special agate tools of the shape of a horn. Flint stone, blood stone, and wolf’s teeth are sometimes, but gradually more seldom, employed. Burnish till a full, fine luster appears; but very carefully avoid dents and lines, not to speak of scratches, which would be very hard to mend.

«Gold Enamel Paints.»—

I.—Pure turps 6 pints Copal varnish 1 pint Good gold bronze 6 1⁠/⁠2 pounds Calcis hydrate (dry-slaked lime) 1⁠/⁠2 ounce

Mix the varnish and turps at a gentle heat, then slake well with the lime, and settle for a few days, then pour off the clean portion and mix with the powder.

II.—White hard varnish 1 gallon Methylated spirit 3⁠/⁠4 gallon Gold bronze 12 pounds Finely powdered mica 3 ounces

Mix the varnish and the spirit, reduce the mica to an impalpable powder, mix with the gold, then add to the liquid. Many bronze powders contain a goodly {494} proportion of mica, as it imparts brilliancy. Powdered mother-of-pearl is used also.

«GRAINING WITH PAINT:»

See also Wood.

«Oak Graining.»—Prepare a paint of two-thirds of white lead and one-third of golden ocher with the requisite amount of boiled linseed oil and a little drier, and cover the floor twice with this mixture, which possesses great covering power. When the last coating is dry, paint the floor with a thinly liquid paint consisting of varnish and sienna, applying the same in the longitudinal direction of the boards. Treat a strip about 20 inches wide at a time, and draw at once a broad paint brush or, in the absence of such, an ordinary brush or goose feather along the planks through the wet paint, whereupon the floor will acquire a nicely grained appearance. The paint requires several days to dry. A subsequent coating of varnish will cause the graining to stand out still more prominently.

«Birch.»—Imitations of birch are usefully employed for furniture. The ground should be a light, clean buff, made from white lead, stained with either yellow ocher or raw sienna in oil. In graining, brush over the surface with a thin wash of warm brown, making the panel of 2 or 3 broad color shades. Then take a large mottler and mottle the darker parts into the light, working slantwise, as for maple, but leaving a broad and stiff mark. While this is still wet soften the panel and then slightly mottle across the previous work to break it up. When thoroughly dry, carefully wet the work over with clean water and clean mottler, and put in darker overgrain with a thin oak overgrainer or overgrainer in tubes.

«Maple.»—Sixty pounds white lead; 1 ounce deep vermilion; 1 ounce lemon chrome.

«Ash.»—Sixty pounds white lead; 1 ounce deep vermilion; 1 ounce lemon chrome.

«Medium Oak.»—Sixty pounds white lead; 2 pounds French ocher; 1 ounce burnt umber.

«Light Oak.»—Sixty pounds white lead; 1 ounce lemon chrome; 1⁠/⁠2 pound French ocher.

«Dark Oak.»—Sixty pounds white lead; 10 pounds burnt umber; 1 1⁠/⁠2 pounds medium Venetian red.

«Satin Wood.»—Sixty pounds white lead; 1 ounce deep vermilion; 1 1⁠/⁠2 pounds lemon chrome.

«Pollard Oak.»—Seventy-five pounds white lead; 20 pounds French ocher; 3 pounds burnt umber; 2 1⁠/⁠2 pounds medium Venetian red.

«Pitch Pine.»—Sixty pounds white lead; 1⁠/⁠4 pound French ocher; 1⁠/⁠2 pound medium Venetian red.

«Knotted Oak.»—Sixty pounds white lead; 9 pounds French ocher; 3 1⁠/⁠2 pounds burnt umber.

«Italian Walnut.»—Sixty pounds white lead; 6 pounds French ocher; 1 1⁠/⁠2 pounds burnt umber; 1 1⁠/⁠4 pounds medium Venetian red.

«Rosewood.»—Nine and one-half pounds burnt umber; 40 pounds medium Venetian red; 10 pounds orange chrome.

«Dark Mahogany.»—Nine and one-half pounds burnt umber; 40 pounds medium Venetian red; 10 pounds orange chrome.

«Light Mahogany.»—Sixty pounds white lead; 3 pounds burnt umber; 10 pounds medium Venetian red.

«American Walnut.»—Thirty pounds white lead; 9 pounds French ocher; 4 pounds burnt umber; 1 pound medium Venetian red.

«LUMINOUS PAINTS.»

The illuminating power of the phosphorescent masses obtained by heating strontium thiosulphate or barium thiosulphate is considerably increased by the addition, before heating, of small quantities of the nitrates of uranium, bismuth, or thorium. Added to calcium thiosulphate, these nitrates do not heighten the luminosity or phosphorescence. The product from strontium thiosulphate is more luminous than that of the barium compound. Among the best luminous paints are the following:

I.—Lennord’s.—One hundred parts, by weight, of strontium carbonate; 100 parts, by weight, of sulphur; 0.5 parts, by weight, of potassium chloride; 0.5 parts, by weight, of sodium chloride; 0.4 parts, by weight, of manganese chloride. The materials are heated for three-quarters of an hour to one hour, to about 2,372° F. The product gives a violet light.

II.—Mourel’s.—One hundred parts, by weight, of strontium carbonate; 30 parts, by weight, of sulphur; 2 parts, by weight, of sodium carbonate; 0.5 parts, by weight, of sodium chloride; 0.2 parts, by weight, of manganese sulphate. The method of treatment is the same as in the first, the phosphorescence deep yellow. {495}

III.—Vanino’s.—Sixty parts, by weight, of strontium thiosulphate; 12 parts, by weight, of a 0.5 per cent acidified alcoholic solution of bismuth nitrate; 6 parts, by weight, of a 0.5 per cent alcoholic solution of uranium nitrate. The materials are mixed, dried, brought gradually to a temperature of 2,372° F., and heated for about an hour. The phosphorescence is emerald green.

IV.—Balmain’s.—Twenty parts, by weight, of calcium oxide (burnt lime), free from iron; 6 parts, by weight, of sulphur; 2 parts, by weight, of starch; 1 part, by weight, of a 0.5 per cent solution of bismuth nitrate; 0.15 parts, by weight, of potassium chloride; 0.15 parts, by weight, of sodium chloride. The materials are mixed, dried, and heated to 1,300° C. (2,372° F.). The product gives a violet light.

To make these phosphorescent substances effective, they are exposed for a time to direct sunlight; or a mercury lamp may be used. Powerful incandescent gas light also does well, but requires more time.

«PAINTS FOR METAL SURFACES:»

«Blackening Ornaments of Iron.»—I.—To give iron ornaments a black-brown to black color, proceed in the following manner: The articles are treated with corrosives, cleaned of all adhering grease, and placed in a 10 per cent solution of potassium bichromate, dried in the air, and finally held over an open, well-glowing, non-sooting fire for 2 minutes. The first coloring is usually black brown, but if this process is repeated several times, a pure black shade is obtained. Special attention has to be paid to removing all grease, otherwise the greasy spots will not be touched by the liquid, and the coloring produced will become irregular. Benzine is employed for that purpose and the articles must not be touched with the fingers afterwards.

II.—This process protects the iron from rust for a long time. The treatment consists in coating the objects very uniformly with a thin layer of linseed-oil varnish, and burning it off over a charcoal fire. During the deflagration the draught must be stopped. The varnish will first go up in smoke with a strong formation of soot, and finally burn up entirely. The process is repeated, i. e., after one coating is burned off a new one is applied, until the parts exhibit a uniformly handsome, deep-black color. Next, wipe off the covering with a dry rag and heat again, but only moderately. Finally, the articles are taken from the fire and rubbed with a rag well saturated with linseed-oil varnish. The black turns completely dull, and forms a real durable covering for the objects.

«Black for Polished Iron Pieces.»—Apply successive layers of a very concentrated solution of nitrate of manganese dissolved in alcohol over a gentle fire and the water bath. The surfaces to be blackened should be previously heated. By repeating the layers all the tints between brownish black and bluish black may be obtained.

«Glossy Black for Bicycles, etc.»—

Amber 8 ounces Linseed oil 4 ounces Asphaltum 1 1⁠/⁠2 ounces Rosin 1 1⁠/⁠2 ounces Oil turpentine 8 ounces

Heat the linseed oil to boiling point, add the amber, asphaltum, and rosin, and when all melted remove from the fire and gradually add the turpentine.

«Japan Black.»—The following is a good japan black for metal surfaces: Take 12 ounces of amber and 2 ounces of asphaltum. Fuse by heat, and add 1⁠/⁠2 pint boiled oil and 2 ounces of rosin. When cooling add 16 ounces of oil of turpentine.

«Brass and Bronze Protective Paint.»—As a protective covering, especially for brass and bronze objects, a colorless celluloid solution is recommended, such as is found in trade under the name of “Zapon” (q. v.).

«Paint for Copper.»—Dissolve 1 ounce of alum in 1 quart of warm soft water. When cold add flour to make it about the consistency of cream, then add 1⁠/⁠2 thimble of rosin and 1⁠/⁠2 ounce of sugar of lead.

«Priming Iron.»—The following, if carefully carried out, gives the best satisfaction: The first step consists in thoroughly cleaning the surface of the iron, removing all adhesions in the way of dirt, rust, etc., before the question of priming is considered. As paint in this instance is applied more with a view of protecting the iron from atmospheric influences, rather than for a decorative effect, careful attention should be devoted for securing a base or surface which is calculated to produce a thorough and permanent application. A great deal depends upon the nature of the metal to be painted. Common cast iron, for instance, possessing a rough exterior, {496} with ordinary precautions can be more readily painted with the prospect of a permanent adhesion of the paint, than a planed steel or wrought-iron surface. With the latter it has been demonstrated that a hard and elastic paint is needed, while with regard to cast iron, other paints containing iron oxides are more suitable. For good drying and covering properties, as well as elasticity, a good boiled oil to which has been added an adequate proportion of red lead will be found to form an excellent paint for smooth metal surfaces. The primary object is to protect the surface of the iron from moisture for the purpose of avoiding rust. The priming must therefore be carried out so that it will stick, after which subsequent coats may be added if desired.

It is advisable that articles made of iron should first be coated with linseed-oil varnish. It dries slowly, hardens, and enables the operator afterwards to exercise an effective control over the condition of his material. Iron must be absolutely dry and free from rust when it is to be painted. It is best to apply next a coating of hot linseed oil; when dry this should be followed by a priming of pure red lead in good linseed oil, and the iron should then be painted as desired, using ground oil paints and leaving an interval of a week between each coating. Cementing should be done after the red lead priming, but the last coat must not be given until the whole is thoroughly dry. Bright oil paints and an upper coating with plenty of oil resist the effects of heat better than thin coatings; moreover, rust can be detected in its early stages with the former. Coatings of tar and asphalt (asphalt dissolved in turpentine) are practicable for underground pipes, but are not adapted for pipes exposed to the air, as they are quickly spoiled. Asphalt varnish, used for coating coal scuttles, fire screens, etc., consists of asphalt dissolved in linseed-oil varnish. Iron stoves and stovepipes are best coated with graphite.

«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.