Henley's Twentieth Century Formulas, Recipes and Processes

Part 79

Chapter 794,005 wordsPublic domain

«Coloring Common Gold.»—In coloring gold below 18 carat, the following mixture may be used with success, and if carefully employed, even 12 carat gold may be colored by it: Take nitrate of potassa (saltpeter), 4 parts, by weight; alum, 2 parts; and common salt, 2 parts. Add sufficient warm water to mix the ingredients into a thin paste; place the mixture in a small pipkin or crucible and allow to boil. The article to be colored should be suspended by a wire and dipped into the mixture, where it should remain from 10 to 20 minutes. The article should then be removed and well rinsed in hot water, when it must be scratch brushed, again rinsed and returned to the coloring salts for a few minutes; it is then to be again rinsed in hot water, scratch brushed, and finally brushed with soap and hot water, rinsed in hot water, and placed in boxwood sawdust. The object being merely to remove the alloy, as soon as the article has acquired the proper color of fine gold it may be considered sufficiently acted upon by the above mixture. The coloring salts should not be used for gold of a lower standard than 12 carat, and, even for this quality of gold, some care must be taken when the articles are of a very slight make.

«Shades of Red, etc., on Matt Gold Bijouterie.»—For the production of the red and other shades on matt gold articles, the so-called gold varnishes are employed, which consist of shellac dissolved in alcohol and are colored with gum rosins. Thus a handsome golden yellow is obtained from shellac, 35 parts; seed-lac, 35 parts; dragon’s blood, 50 parts; gamboge, 50 parts; dissolved in 400 parts of alcohol; the clear solution is decanted and mixed with 75 parts of Venice turpentine. By changing the amounts of the coloring rosins, shades from bright gold yellow to copper color are obtained. The varnish is applied evenly and after drying is wiped off from the raised portions of the article by means of a pad of wadding dipped into alcohol, whereby a handsome patination effect is produced, since the lacquer remains in the cavities. Chased articles are simply rubbed with earth colors ground into a paste with turpentine oil, for which purpose burnt sienna, fine ochers of a golden color, golden yellow, and various shades of green are employed.

I.—Yellow wax 32 parts Red bole 3 parts Crystallized verdigris 2 parts Alum 2 parts

II.—Yellow wax 95 parts Red bole 64 parts Colcothar 2 parts Crystallized verdigris 32 parts Copper ashes 20 parts Zinc vitriol 32 parts Green vitriol 16 parts Borax 1 part

The wax is melted and the finely powdered chemicals are stirred in, in rotation. If the gilt bronze goods are to obtain a lustrous orange shade, apply a mixture of ferric oxide, alum, cooking salt, and vinegar in the heated articles by means of a brush, heating to about 266° F. until the shade commences to turn black and water sprinkled on will evaporate with a hissing sound, then cool in water, dip in a mixture of 1 part of nitric acid with 40 parts of water, rinse {432} thoroughly, dry, and polish. For the production of a pale-gold shade use a wax preparation consisting of:

III.—Yellow wax 19 parts Zinc vitriol 10 parts Burnt borax 3 parts

Green-gold color is produced by a mixture of:

IV.—Saltpeter 6 parts Green vitriol 2 parts Zinc vitriol 1 part Alum 1 part

«To Matt Gilt Articles.»—If it is desired to matt gilt articles partly or entirely, the portions which are to remain burnished are covered with a mixture of chalk, sugar, and mucilage, heating until this “stopping-off” covering shows a black color. On the places not covered apply a matting powder consisting of:

Saltpeter 40 parts Alum 25 parts Cooking salt 35 parts

Heat the objects to about 608° F., whereby the powder is melted and acquires the consistency of a thin paste. In case of too high a temperature decomposition will set in.

«To Find the Number of Carats.»—To find the number of carats of gold in an object, first weigh the gold and mix with seven times its weight in silver. This alloy is beaten into thin leaves, and nitric acid is added; this dissolves the silver and copper. The remainder (gold) is then fused and weighed; by comparing the first and last weights the number of carats of pure gold is found. To check repeat several times.

«Acid Test for Gold.»—The ordinary ready method of ascertaining whether a piece of jewelry is made of gold consists in touching it with a glass stopper wetted with nitric acid, which leaves gold untouched, but colors base alloys blue from the formation of nitrate of copper.

«Imitation Diamonds.»—I.—Minium, 75 parts (by weight); washed white sand, 50 parts; calcined potash, 18 parts; calcined borax, 6 parts; bioxide of arsenic, 1 part. The sand must be washed in hydrochloric acid and then several times in clean water. The specific gravity of this crystal glass is almost the same as that of the diamond.

II.—Washed white sand, 100 parts (by weight): minium, 35 parts; calcined potash, 25 parts; calcined borax, 20 parts; nitrate of potash (crystals), 10 parts; peroxide of manganese, 5 parts. The sand must be washed as above stated.

«Diamantine.»—This substance consists of crystallized boron, the basis of borax. By melting 100 parts of boracic acid and 80 parts of aluminum crystals is obtained the so-called bort, which even attacks diamond. The diamantine of commerce is not so hard.

«To Refine Board Sweepings.»—The residue resulting from a jobbing jeweler’s business, such as board sweepings and other residuum, which is continually accumulating and which invariably consists of all mixed qualities of standard, may have the precious metals recovered therefrom in a very simple manner, as follows: Collect the residue and burn it in an iron ladle or pan, until all grease or other organic matter is destroyed. When cool mix with 1⁠/⁠5 part soda-ash, and melt in a clay crucible. When the metal is thoroughly melted it will leave the flux and sink to the bottom of the crucible; at this stage the flux assumes the appearance of a thin fluid, and then is the time to withdraw the pot from the fire. The metal in the crucible—but not the flux—may now be poured into a vessel of water, stirring the water in a circular direction while the metal is being poured in, which causes it to form into small grains, and so prepares it for the next process. Dissolve the grains in a mixture of nitric acid and water in equal quantities. It takes about four times the quantity of liquid as metal to dissolve. The gold remains undissolved in this mixture, and may be recovered by filtering or decanting the liquid above it in the dissolving vessel; it is then dried, mixed with a little flux, and melted in the usual manner, whereupon pure gold will be obtained. To recover the silver, dilute the solution which has been withdrawn from the gold with six times its bulk of water, and add by degrees small quantities of finely powdered common salt, and this will throw down the silver into a white, curdy powder of chloride of silver. Continue to add salt until no cloudiness is observed in the solution, when the water above the sediment may be poured off; the sediment is next well washed with warm water several times, then dried and melted in the same manner as the gold, and you will have a lump of pure silver.

«Restoration of the Color of Turquoises.»—After a certain time turquoises lose a part of their fine color. It is easy to restore the color by immersing them in a solution of carbonate of soda. But it seems that the blue cannot be restored anew after this operation, if it again becomes dull. The above applies to {433} common turquoises, and not to those of the Orient, of which the color does not change.

«Colorings for Jewelers’ Work.»—I.—Take 40 parts of saltpeter; 30 parts of alum; 30 parts of sea salt; or 100 grams of liquid ammonia; 3 parts sea salt; and 100 parts water. This is heated without bringing it to a boil, and the articles dipped into it for from 2 to 3 minutes, stirring the liquid constantly; after this bath they are dipped in alum water and then thoroughly rinsed in clean water.

II.—One hundred parts of calcium bromide and 2 parts of bromium. The objects are allowed to remain in this solution (which must be also constantly stirred) for from 2 to 3 minutes, then washed in a solution of sodium hyposulphite, after which they must be rinsed in clean water.

III.—Thirty parts of verdigris; 30 parts of sea salt; 30 parts of hematite; 30 parts of sal ammoniac, and 5 parts of alum. This must be all ground up together and mixed with strong vinegar; or we may also use 100 parts of verdigris; 100 parts of hydrochlorate of ammonia; 65 parts of saltpeter, and 40 parts of copper filings, all of which are to be well mixed with strong vinegar.

«22-Carat Solder.»—Soldering is a process which, by means of a more fusible compound, the connecting surfaces of metals are firmly secured to each other, but, for many practical purposes, it is advisable to have the fusing point of the metal and solder as near each other as possible, which, in the majority of cases, preserves a union more lasting, and the joint less distinguishable, in consequence of the similarity of the metal and solder in color, which age does not destroy, and this is not the case with solders the fusible points of which are very low. The metal to be soldered together must have an affinity for the solder, otherwise the union will be imperfect; and the solder should likewise act upon the metal, partly by this affinity or chemical attraction, and partly by cohesive force, to unite the connections soundly and firmly together. Solders should therefore be prepared suitable to the work in hand, if a good and lasting job is to be made. It should always be borne in mind that the higher the fusing point of the gold alloy—and this can be made to vary considerably, even with any specified quality—the harder solder must be used, for, in the case of a more fusible mixture of gold, the latter would melt before the solder and cause the work to be destroyed. A very good formula for the first, or ordinary, 22-carat alloy is this:

dwts. grs. Fine gold 1 0 Fine silver 0 3 Fine copper 0 2 ──────── 1 5

This mixture will answer all the many purposes of the jobber; for soldering high quality gold wares that come for repairs, particularly wedding rings, it will be found admirably suited. If an easier solder is wanted, and such is very often the case with jobbing jewelers, especially where several solderings have to be accomplished, it is as well to have at hand a solder which will not disturb the previous soldering places, for if this is not prevented a very simple job is made very difficult, and a lot of time and patience wholly wasted. To guard against a thing of this kind the following solder may be employed on the top of the previous one:

dwts. grs. Fine gold 1 0 Fine silver 0 3 Yellow brass 0 2 ──────── 1 5

This solder is of the same value as the previous one, but its melting point is lower, and it will be found useful for many purposes that can be turned to good account in a jobbing jeweler’s business.

«JEWELERS’ ALLOYS:»

See also Gold Alloys, under Alloys.

Gold of 22 carats fine being so little used is intentionally omitted.

I.—Gold of 18 Carats, Yellow Tint.—Gold, 15 pennyweights; silver, 2 pennyweights, 18 grains; copper, 2 pennyweights, 6 grains.

II.—Gold of 18 Carats, Red Tint.—Gold, 15 pennyweights; silver, 1 pennyweight, 18 grains; copper, 3 pennyweights, 6 grains.

III.—Spring Gold of 16 Carats.—Gold, 1 ounce, 16 pennyweights; silver, 6 pennyweights; copper, 12 pennyweights. This when drawn or rolled very hard makes springs little inferior to steel.

IV.—Jewelers’ Fine Gold, Yellow Tint, 16 Carats Nearly.—Gold, 1 ounce; silver, 7 pennyweights; copper, 5 pennyweights.

V.—Gold of Red Tint, 16 Carats.—Gold, 1 ounce; silver, 2 pennyweights; copper, 8 pennyweights.

Sterling Gold Alloys.—I.—Fine gold, 18 pennyweights, 12 grains; fine silver, 1 pennyweight; fine copper, 12 grains.

II.—Dry Colored Gold Alloys, 17 Carat.—Fine gold, 15 pennyweights; fine silver, 1 pennyweight, 10 grains; fine copper, 4 pennyweights, 17 grains.

III.—18 Carat.—Fine gold, 1 ounce; fine silver, 4 pennyweights, 10 grains; fine copper, 2 pennyweights, 5 grains.

IV.—18 Carat.—Fine gold, 15 pennyweights; fine silver, 2 pennyweights, 4 grains; fine copper, 2 pennyweights, 19 grains.

V.—18 Carat.—Fine gold, 18 pennyweights; fine silver, 2 pennyweights, 18 {436} grains; fine copper, 3 pennyweights, 18 grains.

VI.—19 Carat.—Fine gold, 1 ounce; fine silver, 2 pennyweights, 6 grains; fine copper, 3 pennyweights, 12 grains.

VII.—20 Carat.—Fine gold, 1 ounce; fine silver, 2 pennyweights; fine copper, 2 pennyweights, 4 grains.

VIII.—22 Carat.—Fine gold, 18 pennyweights; fine silver, 12 grains; fine copper, 1 pennyweight, 3 grains.

IX.—Gold Solder for the Foregoing Alloys.—Take of the alloyed gold you are using, 1 pennyweight; fine silver, 6 grains.

X.—Alloy for Dry Colored Rings.—Fine gold, 1 ounce; fine silver, 4 pennyweights, 6 grains; fine copper, 4 pennyweights, 6 grains.

XI.—Solder.—Scrap gold, 2 ounces; fine silver, 3 pennyweights; fine copper, 3 pennyweights.

XII.—Dry Colored Scrap Reduced to 35s. Gold.—Colored scrap, 1 ounce, 9 pennyweights, 12 grains; fine silver, 2 pennyweights; fine copper, 17 pennyweights, 12 grains; spelter, 4 pennyweights.

«To Quickly Remove a Ring from a Swollen Finger.»—If the ring is of gold, pull the folds of the swollen muscles apart, so that it can be seen, then drop on it a little absolute alcohol and place the finger in a bowl of metallic mercury. In a very few minutes the ring will snap apart. If the ring is of brass, scrape the surface slightly, or put on a few drops of a solution of oxalic acid, or even strong vinegar, let remain in contact for a moment or two, then put into the mercury, and the result will be as before.

«Soldering a Jeweled Ring.»—In order to prevent the bursting of the jewels of a ring while the latter is being soldered, cut a juicy potato into halves and make a hollow in both portions in which the part of the ring having jewels may fit exactly. Wrap the jeweled portion in soft paper, place it in the hollow, and bind up the closed potato with binding wire. Now solder with easy-flowing gold solder, the potato being held in the hand. Another method is to fill a small crucible with wet sand, bury the jeweled portion in the sand, and solder in the usual way.

JEWELRY, TO CLEAN: See Cleaning Preparations and Methods.

«Kalsomine»

Sodium carbonate 8 parts Linseed oil 32 parts Hot water 8 parts White glue 12 parts Whiting 160 parts

Dissolve the sodium carbonate in the hot water, add the oil and saponify by heating and agitation. Cover the glue, broken into small pieces, with cold water and let soak overnight. In the morning pour the whole on a stout piece of stuff and let the residual water drain off, getting rid of as much as possible by slightly twisting the cloth. Throw the swelled glue into a capsule, put on the water bath, and heat gently until it is melted. Add the saponified oil and mix well; remove from the bath, and stir in the whiting, a little at a time, adding hot water as it becomes necessary. When the whiting is all stirred in, continue adding hot water, until a liquid is obtained that flows freely from the kalsomining brush.

The addition of a little soluble blue to the mixture increases the intensity of the white.

«Sizing Walls for Kalsomine.»—A size to coat over “hot walls” for the reception of the kalsomine is made by using shellac, 1 part; sal soda, 1⁠/⁠2 part. Put these ingredients in 1⁠/⁠2 gallon of water and dissolve by steady heat. Another size is made of glue size prepared in the usual way, and alum. To 1⁠/⁠2 pound of white glue add 3⁠/⁠4 pound of alum, dissolving the alum in hot water before adding it to the glue size.

KARATS, TO FIND NUMBER OF: See Jewelers’ Formulas.

KERAMICS: See Ceramics.

KERIT: See Rubber.

KEROCLEAN: See Cleaning Preparations and Methods.

«KEROSENE DEODORIZER:»