Part 131

«Cleaning Brass Mountings on Clock Cases, etc.»—The brass mountings are first cleaned of dirt by dipping them for a short time into boiling soda lye, and next are pickled, still warm, if possible, in a mixture consisting of nitric acid, 60 parts; sulphuric acid, 40 parts; cooking salt, 1 part; and shining soot (lampblack), 1⁠/⁠2 part, whereby they acquire a handsome golden-yellow coloring. The pickling mixture, however, must not be employed immediately after pouring together the acids, which causes a strong generation of heat, but should settle for at least {207} 1 day. This makes the articles handsomer and more uniform. After the dipping the objects are rinsed in plenty of clean water and dried on a hot, iron plate, and at the same time warmed for lacquering. Since the pieces would be lacquered too thick and unevenly in pure gold varnish, this is diluted with alcohol, 1 part of gold varnish sufficing for 10 parts of alcohol. Into this liquid dip the mountings previously warmed and dry them again on the hot plate.

«Gilt Zinc Clocks.»—It frequently happens that clocks of gilt zinc become covered with green spots. To remove such spots the following process is used: Soak a small wad of cotton in alkali and rub it on the spot. The green color will disappear at once, but the gilding being gone, a black spot will remain. Wipe off well to remove all traces of the alkali. To replace the gilding, put on, by means of liquid gum arabic, a little bronze powder of the color of the gilding. The powdered bronze is applied dry with the aid of a brush or cotton wad. When the gilding of the clock has become black or dull from age, it may be revived by immersion in a bath of cyanide of potassium, but frequently it suffices to wash it with a soft brush in soap and water, in which a little carbonate of soda has been dissolved. Brush the piece in the lather, rinse in clean water, and dry in rather hot sawdust. The piece should be dried well inside and outside, as moisture will cause it to turn black.

«To Clean Gummed Up Springs.»—Dissolve caustic soda in warm water, place the spring in the solution and leave it there for about one half hour. Any oil still adhering may now easily be taken off with a hard brush; next, dry the spring with a clean cloth. In this manner gummed up parts of tower clocks, locks, etc., may be quickly and thoroughly cleaned, and oil paint may be removed from metal or wood. The lye is sharp, but free from danger, nor are the steel parts attacked by it.

«To Clean Soldered Watch Cases.»—Gold, silver, and other metallic watch cases which in soldering have been exposed to heat, are laid in diluted sulphuric acid (1 part acid to 10 to 15 parts water), to free them from oxide. Heating the acid accelerates the cleaning process. The articles are then well rinsed in water and dried. Gold cases are next brushed with powdered tripoli moistened with oil, to remove the pale spots caused by the heat and boiling, and to restore the original color. After that they are cleaned with soap water and finally polished with rouge. Silver cases are polished after boiling, with a scratch brush dipped in beer.

«A Simple Way to Clean a Clock.»—Take a bit of cotton the size of a hen’s egg, dip it in kerosene and place it on the floor of the clock, in the corner; shut the door of the clock, and wait 3 or 4 days. The clock will be like a new one—and if you look inside you will find the cotton batting black with dust. The fumes of the oil loosen the particles of dust, and they fall, thus cleaning the clock.

«To Restore the Color of a Gold or Gilt Dial.»—Dip the dial for a few seconds in the following mixture: Half an ounce of cyanide of potassium is dissolved in a quart of hot water, and 2 ounces of strong ammonia, mixed with 1⁠/⁠2 an ounce of alcohol, are added to the solution. On removal from this bath, the dial should immediately be immersed in warm water, then brushed with soap, rinsed, and dried in hot boxwood dust. Or it may simply be immersed in dilute nitric acid; but in this case any painted figures will be destroyed.

«A Bath for Cleaning Clocks.»—In an enameled iron or terra-cotta vessel pour 2,000 parts of water, add 50 parts of scraped Marseilles soap, 80 to 100 parts of whiting, and a small cup of spirits of ammonia. To hasten the process of solution, warm, but do not allow to boil.

If the clock is very dirty or much oxidized, immerse the pieces in the bath while warm, and as long as necessary. Take them out with a skimmer or strainer, and pour over them some benzine, letting the liquid fall into an empty vessel. This being decanted and bottled can be used indefinitely for rinsing.

If the bath has too much alkali or is used when too hot, it may affect the polish and render it dull. This may be obviated by trying different strengths of the alkali. Pieces of blued steel are not injured by the alkali, even when pure.

«To Remove a Figure or Name from a Dial.»—Oil of spike lavender may be employed for erasing a letter or number. Enamel powder made into a paste with water, oil, or turpentine is also used for this purpose. It should be previously levigated so as to obtain several degrees of fineness. The powder used for repolishing the surface, where an impression has been removed, must be extremely fine. It is applied with a piece of {208} pegwood or ivory. The best method is to employ diamond powder. Take a little of the powder, make into a paste with fine oil, on the end of a copper polisher the surface of which has been freshly filed and slightly rounded. The marks will rapidly disappear when rubbed with this. The surface is left a little dull; it may be rendered bright by rubbing with the same powder mixed with a greater quantity of oil, and applied with a stick of pegwood. Watchmakers will do well to try on disused dials several degrees of fineness of the diamond powder.

«Cleaning Pearls.»—Pearls turn yellow in the course of time by absorbing perspiration on account of being worn in the hair, at the throat, and on the arms. There are several ways of rendering them white again.

I.—The best process is said to be to put the pearls into a bag with wheat bran and to heat the bag over a coal fire, with constant motion.

II.—Another method is to bring 8 parts each of well-calcined, finely powdered lime and wood charcoal, which has been strained through a gauze sieve, to a boil with 500 parts of pure rain water, suspend the pearls over the steam of the boiling water until they are warmed through, and then boil them in the liquid for 5 minutes, turning frequently. Let them cool in the liquid, take them out, and wash off well with clean water.

III.—Place the pearls in a piece of fine linen, throw salt on them, and tie them up. Next rinse the tied-up pearls in lukewarm water until all the salt has been extracted, and dry them at an ordinary temperature.

IV.—The pearls may also be boiled about 1⁠/⁠4 hour in cow’s milk into which a little cheese or soap has been scraped; take them out, rinse off in fresh water, and dry them with a clean, white cloth.

V.—Another method is to have the pearls, strung on a silk thread or wrapped up in thin gauze, mixed in a loaf of bread of barley flour and to have the loaf baked well in an oven, but not too brown. When cool remove the pearls.

VI.—Hang the pearls for a couple of minutes in hot, strong, wine vinegar or highly diluted sulphuric acid, remove, and rinse them in water. Do not leave them too long in the acid, otherwise they will be injured by it.

«GLASS CLEANING:»

«Cleaning Preparation for Glass with Metal Decorations.»—Mix 1,000 parts of denaturized spirit (96 per cent) with 150 parts, by weight, of ammonia; 20 parts of acetic ether; 15 parts of ethylic ether; 200 parts of Vienna lime; 950 parts of bolus; and 550 parts of oleine. With this mixture both glass and metal can be quickly and thoroughly cleaned. It is particularly recommended for show windows ornamented with metal.

«Paste for Cleaning Glass.»—

Prepared chalk 6 pounds Powdered French chalk 1 1⁠/⁠2 pounds Phosphate calcium 2 1⁠/⁠4 pounds Quillaia bark 2 1⁠/⁠4 pounds Carbonate ammonia 18 ounces Rose pink 6 ounces

Mix the ingredients, in fine powder, and sift through muslin. Then mix with soft water to the consistency of cream, and apply to the glass by means of a soft rag or sponge; allow it to dry on, wipe off with a cloth, and polish with chamois.

«Cleaning Optical Lenses.»—For this purpose a German contemporary recommends vegetable pith. The medulla of rushes, elders, or sunflowers is cut out, the pieces are dried and pasted singly alongside of one another upon a piece of cork, whereby a brush-like apparatus is obtained, which is passed over the surface of the lens. For very small lenses pointed pieces of elder pith are employed. To dip dirty and greasy lenses into oil of turpentine or ether and rub them with a linen rag, as has been proposed, seems hazardous, because the Canada balsam with which the lenses are cemented might dissolve.

«To Remove Glue from Glass.»—If glue has simply dried upon the glass hot water ought to remove it. If, however, the spots are due to size (the gelatinous wash used by painters) when dried they become very refractory and recourse must be had to chemical means for their removal. The commonest size being a solution of gelatin, alum, and rosin dissolved in a solution of soda and combined with starch, hot solutions of caustic soda or of potash may be used. If that fails to remove them, try diluted hydrochloric, sulphuric, or any of the stronger acids. If the spots still remain some abrasive powder (flour of emery) must be used and the glass repolished with jewelers’ rouge applied by means of a chamois skin. Owing to the varied nature of sizes used the above are only suggestions.

«Cleaning Window Panes.»—Take diluted nitric acid about as strong as strong {209} vinegar and pass it over the glass pane, leave it to act a minute and throw on pulverized whiting, but just enough to give off a hissing sound. Now rub both with the hand over the whole pane and polish with a dry rag. Rinse off with clean water and a little alcohol and polish dry and clear. Repeat the process on the other side. The nitric acid removes all impurities which have remained on the glass at the factory, and even with inferior panes a good appearance is obtained.

«To Clean Store Windows.»—For cleaning the large panes of glass of store windows, and also ordinary show cases, a semiliquid paste may be employed, made of calcined magnesia and purified benzine. The glass should be rubbed with a cotton rag until it is brilliant.

«Cleaning Lamp Globes.»—Pour 2 spoonfuls of a slightly heated solution of potash into the globe, moisten the whole surface with it, and rub the stains with a fine linen rag; rinse the globe with clean water and carefully dry it with a fine, soft cloth.

«To Clean Mirrors.»—Rub the mirror with a ball of soft paper slightly dampened with methylated spirits, then with a duster on which a little whiting has been sprinkled, and finally polish with clean paper or a wash leather. This treatment will make the glass beautifully bright.