Part 24

«Graining of Brass.»—Brass parts of timepieces are frequently provided with a dead grained surface. For this purpose they are fastened with flat-headed pins on cork disks and brushed with a paste of water and finest powdered pumice stone. Next they are thoroughly washed and placed in a solution of 10 quarts of water, 30 grains of mercuric nitrate, and 60 grains of sulphuric acid. In this amalgamating solution the objects become at once covered with a layer of mercury, which forms an amalgam with the copper, while the zinc passes into solution. After the articles have again been washed they are treated with graining powder, which consists of silver powder, tartar, and cooking salt. These substances must be pure, dry, and very finely pulverized. The mixing is done with moderate heat. According {131} to whether a coarser or finer grain is desired, more cooking salt or more tartar must be contained in the powder. The ordinary proportions are:

Silver powder 28 28 28 parts Tartar 283 110–140 85 parts Cooking salt 900 370 900 parts

This powder is moistened with water and applied to the object. Place the article with the cork support in a flat dish and rub on the paste with a stiff brush while turning the dish incessantly. Gradually fresh portions of graining powder are put on until the desired grain is obtained. These turn out the rounder the more the dish and brush are turned. When the right grain is attained, rinse off with water, and treat the object with a scratch brush, with employment of a decoction of saponaria. The brushes must be moved around in a circle in brushing with the pumice stone, as well as in rubbing on the graining powder and in using the scratch brush. The required silver powder is produced by precipitating a diluted solution of silver nitrate with some strips of sheet copper. The precipitated silver powder is washed out on a paper filter and dried at moderate heat.

«The Dead, or Matt, Dip for Brass.»—The dead dip is used to impart a satiny or crystalline finish to the surface. The bright dip gives a smooth, shiny, and perfectly even surface, but the dead dip is the most pleasing of any dip finish, and can be used as a base for many secondary finishes.

The dead dip is a mixture of oil of vitriol (sulphuric acid) and aqua fortis (nitric acid) in which there is enough sulphate of zinc (white vitriol) to saturate the solution. It is in the presence of the sulphate of zinc that the essential difference between the bright and the dead dip exists. Without it the dead or matt surface cannot be obtained.

The method generally practiced is to add the sulphate of zinc to the mixed acids (sulphuric and nitric), so that some remains undissolved in the bottom of the vessel. It is found that the sulphate of zinc occurs in small crystals having the appearance of very coarse granulated sugar. These crystals readily settle to the bottom of the vessel and do not do the work of matting properly. If they are finely pulverized the dip is slightly improved, but it is impossible to pulverize such material to a fineness that will do the desired work. The use of sulphate of zinc, then, leaves much to be desired.

The most modern method of making up the dead dip is to produce the sulphate of zinc directly in the solution and in the precipitated form. It is well known that the most finely divided materials are those which are produced by precipitation, and in the dead dip it is very important that the sulphate of zinc shall be finely divided so that it will not immediately settle to the bottom. Therefore it should be precipitated so that when it is mixed with the acids it will not settle immediately. The method of making the sulphate of zinc directly in the solution is as follows:

Take 1 gallon of yellow aqua fortis (38° F.) and place in a stone crock which is surrounded with cold water. The cold water is to keep the heat, formed by the reaction, from evaporating the acid. Add metallic zinc in small pieces until the acid will dissolve no more. The zinc may be in any convenient form—sheet clippings, lumps, granulated, etc., that may be added little by little. If all is added at once it will boil over. When the acid will dissolve no more zinc it will be found that some of the acid has evaporated by the heat, and it will be necessary to add enough fresh acid to make up to the original gallon. When this is done add 1 gallon of strong oil of vitriol. The mixture should be stirred with a wooden paddle while the oil of vitriol is being added.

As the sulphuric acid is being added the solution begins to grow milky, and finally the whole has the consistency of thick cream. This is caused by the sulphuric acid (oil of vitriol) precipitating out the sulphate of zinc. Thus the very finely divided precipitate of sulphate of zinc is formed. If one desires to use known quantities of acid and zinc the following amounts may be taken: Oil of vitriol, 1 gallon; aqua fortis (38° F.), 1 gallon; metallic zinc, 6 ounces.

In dissolving the zinc in the aqua fortis it is necessary to be sure that none remains undissolved in the bottom.

The dead or matt dip is used hot, and, therefore, is kept in a stone crock surrounded with hot water. The articles to be matted are polished and cleaned, and the dip thoroughly stirred with a wooden paddle, so as to bring up the sulphate of zinc which has settled. Dip the work in the solution and allow it to remain until the matt is obtained. This is a point which can be learned only by experience. When the brass article is first introduced there is a rapid action on the surface, but in a few seconds this slows down. Remove the article and rinse and immediately dip into the usual bright dip. This {132} is necessary for the reason that the dead dip produces a dark coating upon the surface, which, were it left on, would not show the real effect or the color of the metal. The bright dip, however, removes this and exposes the true dead surface.

The usual rule for making up the dead dip is to use equal parts of oil of vitriol and aqua fortis; but these may be altered to suit the case. More oil of vitriol gives a finer matt, while a larger quantity of aqua fortis will give a coarser matt. When the dip becomes old it is unnecessary to add more zinc, as a little goes into the solution each time anything is dipped. After a while, however, the solution becomes loaded with copper salts, and should be thrown away.

A new dip does not work well, and will not give good results when used at once. It is usual to allow it to remain over night, when it will be found to be in a better working condition in the morning. A new dip will frequently refuse to work, and the addition of a little water will often start it. The water must be used sparingly, however, and only when necessary. Water, as a usual thing, spoils a dead dip, and must be avoided. After a while it may be necessary to add a little more aqua fortis, and this may be introduced as desired. Much care is needed in working the dead dip, and it requires constant watching and experience. The chief difficulty in working the dead dip is to match a given article. The only way that it can be done is to “cut and try,” and add aqua fortis or oil of vitriol as the case requires.

The dead or matt dip can be obtained only upon brass or German silver; in other words, only on alloys which contain zinc. The best results are obtained upon yellow brass high in zinc.

«To Improve Deadened Brass Parts.»—Clock parts matted with oilstone and oil, such as the hour wheels, minute wheels, etc., obtain, by mere grinding, a somewhat dull appearance, with a sensitive surface which readily takes spots. This may be improved by preparing the following powder, rubbing a little of it on a buff stick, and treating the deadened parts, which have been cleansed with benzine, by rubbing with slight pressure on cork. This imparts to the articles a handsome, permanent, metallic matt luster. The smoothing powder consists of 2 parts of jewelers’ red and 8 parts of lime carbonate, levigated in water, and well dried. Jewelers’ red alone may be employed, but this requires some practice and care, especially in the treatment of wheels, because rays are liable to form from the teeth toward the center.

«Pickle for Brass.»—Stir 10 parts (by weight) of shining soot or snuff, 10 parts of cooking salt, and 10 parts of red tartar with 250 parts of nitric acid, and afterwards add 250 parts of sulphuric acid; or else mix 7 parts of aqua fortis (nitric acid) with 10 parts of English sulphuric acid. For the mixing ratio of the acid, the kind and alloy of the metal should be the guidance, and it is best found out by practical trials. The better the alloy and the less the percentage of zinc or lead, the handsomer will be the color. Genuine bronze, for instance, acquires a golden shade. In order to give brass the appearance of handsome gilding it is often coated with gold varnish by applying same thinly with a brush or sponge and immediately heating the metal over a coal fire.

«Pickling Brass to Look Like Gold.»—To pickle brass so as to make it resemble gold allow a mixture of 6 parts of chemically pure nitric acid and 1 part of English sulphuric acid to act for some hours upon the surface of the brass; then wash with a warm solution, 20 parts of tartar in 50 parts of water, and rub off neatly with dry sawdust. Then coat the article with the proper varnish.

«Pickle for Dipping Brass.»—To improve the appearance of brass, tombac, and copper goods, they are usually dipped. For this purpose they are first immersed in diluted oil of vitriol (brown sulphuric acid), proportion, 1 to 10; next in a mixture of 10 parts of red tartar; 10 parts of cooking salt; 250 parts of English sulphuric acid, as well as 250 parts of aqua fortis (only for a moment), rinsing off well in water and drying in sawdust. For obtaining a handsome matt gold color 1⁠/⁠20 part of zinc vitriol (zinc sulphate) is still added to the pickle.

«Restoration of Brass Articles.»—The brass articles are first freed from adhering dirt by the use of hot soda lye; if bronzed they are dipped in a highly dilute solution of sulphuric acid and rinsed in clean water. Next they are yellowed in a mixture of nitric acid, 75 parts; sulphuric acid, 100 parts; shining lampblack, 2 parts; cooking salt, 1 part; then rinsed and polished and, to prevent oxidation, coated with a colorless spirit varnish, a celluloid varnish being best for this purpose.

«Tempering Brass.»—If hammered too brittle brass can be tempered and made {133} of a more even hardness throughout by warming it, as in tempering steel; but the heat must not be nearly so great. Brass, heated to the blue heat of steel, is almost soft again. To soften brass, heat it nearly to a dull red and allow it to cool, or, if time is an object, it may be cooled by plunging into water.

«Drawing Temper from Brass.»—Brass is rendered hard by hammering or rolling, therefore when a brass object requires to be tempered the material must be prepared before the article is shaped. Temper may be drawn from brass by heating it to a cherry red and then simply plunging it into water, the same as though steel were to be tempered.

BRASS, FASTENING PORCELAIN TO: See Adhesives.

BRASS POLISHES: See Polishes.

BRASS SOLDERS: See Solders.

BRASS BRONZING: See Plating.

BRASS CLEANERS: See Cleaning Preparations and Methods.

BRASS PLATINIZING: See Plating.

BRASS, SAND HOLES IN: See Castings.

BRASSING: See Plating.

BREAD, DOG: See Dog Biscuit.

«BREATH PERFUMES:»

See also Dentifrices.

«Remedies for Fetid Breath.»—Fetid breath may be due to the expelled air (i. e., to disease of the respirational tract), to gases thrown off from the digestive tract, or to a diseased mouth. In the first two cases medication must be directed to the causative diseases, with the last, antisepsis principally and the neutralization of the saliva, also the removal of all residual food of dental caries.

I.—Potassium permanganate 1 part Distilled water 10 parts

Mix and dissolve. Add from 5 to 8 drops of this solution to a glass of water and with it gargle the mouth.

II.—Infusion of salvia 250 parts Glycerine 30 parts Tincture of myrrh 12 parts Tincture of lavender 12 parts Labarraque’s solution 30 parts

Mix. Rinse the mouth frequently with this mixture.

III.—Decoction of chamomile 30 parts Glycerine 80 parts Chlorinated water 15 parts

Mix. Use as a gargle and mouth wash.

IV.—Peppermint water 500 parts Cherry-laurel water 60 parts Borax 25 parts

Mix and dissolve. Use as gargle and mouth wash.

V.—Thymol 3 parts Spirit of cochlearia 300 parts Tincture of rhatany 100 parts Oil of peppermint 15 parts Oil of cloves 10 parts

Mix. Gargle and wash mouth well with 10 drops in a glass of water.

VI.—Salol 5 parts Alcohol 1,000 parts Tincture of white canella 30 parts Oil of peppermint 1 part

Mix. Use as a dentifrice.

VII.—Hydrogen peroxide 25 parts Distilled water 100 parts

Mix. Gargle the mouth twice daily with 2 tablespoonfuls of the mixture in a glass of water.

VIII.—Sodium bicarbonate 2 parts Distilled water 70 parts Spirit of cochlearia 30 parts

Mix a half-teaspoonful in a wineglassful of water. Wash mouth two or three times daily.

«BRICK STAIN.»

To stain brick flat the color of brownstone, add black to Venetian red until the desired shade is obtained. If color ground in oil is used, thin with turpentine, using a little japan as a drier. If necessary to get the desired shade add yellow ocher to the mixture of red and black. If the work is part old and part new, rub the wall down, using a brick {134} for a rubber, until the surface is uniform, and keep it well wet while rubbing with cement water, made by stirring Portland cement into water until the water looks the color of the cement. This operation fills the pores of the brick and makes a smooth, uniform surface to paint on. Tinge the wash with a little dry Venetian red and lampblack. This will help bring the brick to a uniform color, so that an even color can be obtained with one coat of stain.

BRICKS: See Ceramics.

BRICKS OF SAND-LIME: See Stone, Artificial.

BRICK POLISHES: See Polishes.

BRICK WALLS, TO CLEAN: See Cleaning Preparations and Methods and Household Formulas.

BRICK WATERPROOFING: See Waterproofing.

BRICKMAKERS’ NOTES: See Ceramics.

BRIDGE PAINT: See Paint.

BRILLIANTINE: See Hair Preparations.

BRIMSTONE (BURNING): See Pyrotechnics.

BRIONY ROOTS: THEIR PRESERVATION: See Roots.

BRITANNIA METAL: See Alloys.

BRITANNIA METAL, TO CLEAN: See Cleaning Preparations and Methods.

BRITANNIA, SILVERPLATING: See Plating.

BROMINE, ANTISEPTIC: See Antiseptics.

«BROMOFORM.»

Bromoform is insoluble in dilute alcohol, but may be dissolved by the aid of glycerine. The following formula has been devised:

Bromoform 1 part Alcohol 2 parts Compound tincture of cardamon 2 parts Glycerine 1 1⁠/⁠2 parts

Some other formulas are:

«Syrup of Bromoform.»—Bromoform, 5 parts; alcohol (95 per cent), 45 parts; glycerine, 150 parts; syrup, 800 parts. Mix in the order given and place the container in warm water until the syrup becomes perfectly clear.

«Emulsion of Bromoform.»—Add 3 parts of bromoform to 20 parts of expressed oil of almond; emulsify this mixture in the usual manner with 2 parts of powdered tragacanth, 4 parts of powdered acacia, and sufficient water, using for the completed emulsion a total of 120 parts of water, and add, finally, 4 parts of cherry-laurel water.

«Bromoform Rum.»—Bromoform, 1.2 parts; chloroform, 0.8 parts; rum, sufficient to make 120 parts. Claimed to be an effective remedy in the treatment of whooping cough.

BRONZES: See Alloys.

BRONZE CASTING: See Casting.

BRONZE, IMITATION: See Plaster.

BRONZE POLISHES: See Polishes.

BRONZE, RENOVATION OF: See Cleaning Compounds.

«Bronze Powders, Liquid Bronzes, Bronze Substitutes, and Bronzing»

«BRONZE POWDERS.»

Gold bronze is a mixture of equal parts of oxide of tin and sulphur, which are heated for some time in an earthen retort. Silver bronze is a mixture of equal parts of bismuth, tin, and mercury, which are fused in a crucible, adding the mercury only when the tin and the bismuth are in fusion. Next reduce to a very fine powder. To apply these bronzes, white of egg, gum arabic, or varnish is used. It is preferable to apply them dry upon one of the above-named mediums serving as size, than to mix them with the liquids themselves, for in the latter case their luster is impaired.

«Simple Coloring of Bronze Powder.»—In order to impart different colors to {135} bronze powders, such as pale yellow, dark yellow to copper red, the powder is heated with constant stirring in flat iron pans until through the oxidation of the copper—the bronzes consist of the brass powder of an alloy from which the so-called Dutch gold is produced—the desired shade of color is reached. As a rule a very small quantity of fat, wax, or even paraffine is added in this operation. The bronze powders are employed to produce coatings or certain finishes on metals themselves or to give articles of wood, stone, pasteboard, etc., a metallic appearance.

«General Directions for Bronzing.»—The choice of bronze powders is determined by the degree of brilliancy to be obtained. The powder is mixed with strong gum water or isinglass, and laid on with a brush or pencil, almost but not absolutely dry. A piece of soft leather, wrapped around the finger, is dipped into the powder and rubbed over the work; when all this has been covered with the bronze it must be left to dry, and the loose powder is then cleared away with a hair pencil.

«LIQUID BRONZES.»

«Liquid Bronzes.»—I.—For the production of liquid bronze, acid-free varnish should be used, as bronze ground with ordinary varnish will form verdigris. For the deacidification of dammar rosin pour 1,000 parts of petroleum benzine over 350 parts of finely ground dammar rosin, and dissolve by repeated shaking. Next add to the solution 250 parts of a 10-per-cent aqueous solution of caustic soda and shake up well for 10 minutes. After standing for a short time two strata will have formed, the upper one consisting of benzine-rosin solution and the lower, aqueous one containing the resinic acid dissolved as soda salts. Pour off the benzine layers and agitate again assiduously with 250 parts of the 10-per-cent caustic-soda solution. Now set aside for a complete classification and separation of the two liquids. The dammar solution siphoned off will be perfectly free from acid. To obtain gold-bronze varnish add to the deacidified dammar solution about 250 parts of bronze or brocade per liter.

II.—Or else carefully mix 100 parts of finely ground dammar rosin with 30 parts of calcined soda and heat to fusion, in which state it is maintained 2 or 3 hours with frequent stirring. Let cool, grind the turbid mass obtained, and pour a little coal benzine or petroleum benzine over it in a flask. By repeated shaking of the flask the soluble portion of the molten mass is dissolved; filter after allowing to settle; into the filtrate put 300 to 400 parts of bronze powder of any desired shade, the brocades being especially well adapted for this purpose. If the metallic powder remains distributed over the mass for a long time it is of the right consistency; if it deposits quickly it is too thin and a part of the solvent must be evaporated before stirring in the bronze powder.

III.—A liquid bronze, which, while it contains no metallic constituent, yet possesses a metallic luster and a bronze appearance, and answers excellently for many purposes, is made as follows: Dissolve by the aid of gentle heat 10 parts of aniline red and 5 parts of aniline purple in 100 parts of alcohol. When solution is complete, add 5 parts of benzoic acid, raise the heat, and let boil from 5 to 10 minutes, or until the greenish color of the mixture passes over to a clear bronze brown. For “marbling” or bronzing paper articles, this answers particularly well.

«Incombustible Bronze Tincture.»—Finely pulverize 5 parts, by weight, of prime Dammar rosin and 1.5 parts of ammonia soda. Heat gently, and stir frequently, until no more carbonic acid bubbles up. Cool and pulverize again. Put the powder into a glass carboy, and pour over it 50 parts of carbon tetrachloride; let this stand for 2 days, stirring frequently. Then filter. Ten parts of the fluid are mixed with 5 parts of metallic bronze of any desired shade, and put into bottles. Shake well before using.

«General Formulas for Bronzing Preparations.»—I.—Take 240 parts subacetate of copper, 120 parts oxide of zinc in powder form, 60 parts borax, 60 parts saltpeter, and 3.5 parts corrosive sublimate. Prepare a paste from it with oil, stir together, and continue working with boiled linseed oil and turpentine.

II.—Dissolve 120 parts sulphate of copper and add 120 parts chipping of tin; stir well and gather the precipitating copper. After complete drying, grind very finely in boiled linseed oil and turpentine.

III.—Melt in a crucible 60 parts sulphur and 60 parts stannic acid; stir with a clay tube until the mixture takes on the appearance of Dutch gold and pour out. When cold mix the color with boiled linseed oil and turpentine, adding a small quantity of drier. These three bronzes must be covered with a pale, resistant {136} lacquer, otherwise they will soon tarnish in rooms where gas is burned.

«Florentine Bronzes.»—I.—To produce a Florentine bronzing, apply to the articles, which must have previously been dipped, a varnish composed of cherry gum lac dissolved in alcohol. This varnish is put on with a brush, and after that the bronzed piece is passed through the stove.

II.—If the article is of brass it must be given a coat of copper by means of the battery. Next dip a brush in olive oil and brush the piece uniformly; let dry for 5 or 6 hours and place in sawdust. Then heat the article on a moderate charcoal dust fire.

«Preparation of French Bronze.»—French bronze may be prepared by reducing to a powder hematite, 5 parts, and plumbago, 8 parts, and mixing into a paste with spirit of wine. Apply the composition with a soft brush to the article to be bronzed and set it aside for some hours. By polishing with a tolerably hard brush the article will assume the beautiful appearance of real bronze. The desired tint may be regulated by the proportions of the ingredients.

«How to Bronze Metals.»—Prepare a solution of 1 1⁠/⁠2 ounces of sodium hyposulphite in 1 pint of water and add to the same a solution of 1 1⁠/⁠2 ounces of lead acetate dissolved in 1 pint of water.

If, instead of lead acetate, an equal weight of sulphuric acid (1 1⁠/⁠2 ounces) is added to the sodium hyposulphite and the process carried on as before, the brass becomes coated with a very beautiful red, which changes to green, and finally a splendid brown with a green and red iridescence. This last is a very durable coating and may be especially recommended. It is very difficult to obtain exact shades by this process without some experience. The thorough cleansing of all articles from grease by boiling in potash is absolutely necessary to success. By substituting other metal salts for the lead acetate many changes in tints and quality of the coatings can also be effected.