Part 282

Red.—The lac, previously stirred for 6 hours, is mixed with hot oil of trau, and the whole is stirred for a day, after which vermilion is added. The latter should be of good quality, so as to have it brilliant and unchangeable.

The operation of lacquering is then ended, but there are parts to be gilded. These are again covered with a mixture of lac and oil of trau. When this layer is dry the metallic leaves are applied, which are themselves protected by a coating, composed also of lac and oil of trau. All these lac and oil of trau mixtures are carefully filtered, which the natives effect by pressing the liquid on a double filtering surface formed of wadding and of a tissue on which it rests. It can only be applied after several months when the metallic leaf is of gold. In the case of silver or tin the protecting coat can be laid on in a few days. It favorably modifies the white tints of these two metals by communicating a golden color. The hue, at first reddish, gradually improves and acquires its full brilliancy in a few months.

Little information is procurable concerning the processes employed by the Chinese. The wood to be lacquered should be absolutely dry. It receives successive applications, of which the number is not less than 33 for perfect work. When the lac coating attains the thickness of 1⁠/⁠4 of an inch it is ready for the engravers. The Chinese, like the inhabitants of Tonkin, make use of oil of trau to mix with the lac, or oil of aleurites, and the greatest care is exercised in the drying of the different layers. The operation is conducted in dim-lighted rooms specially fitted up for the purpose; the moisture is maintained to a suitable extent by systematically watering the earth which covers the walls of this “cold stove.”

«Lacquer for Aluminum.»—Dissolve 100 parts of gum lac in 300 parts of ammonia, and heat the solution for about 1 hour moderately on the water bath. After cooling, the mixture is ready for use. The aluminum to be coated is cleaned in the customary manner. After it has been painted with the varnish, it is heated in the oven to about 572° F. The coating and heating may be repeated.

«Lacquer for Brass.»—

Annatto 1⁠/⁠4 ounce Saffron 1⁠/⁠4 ounce Turmeric 1 ounce Seed lac in coarse powder 3 ounces Alcohol 1 pint

Digest the annatto, saffron, and turmeric in the alcohol for several days, then strain into a bottle containing the seed lac; cork and shake until dissolved.

«Lacquer for Bronze.»—I.—The following process yields a protective varnish for bronze articles and other metallic objects in various shadings, the lacquer produced excelling in high luster and permanency: Fill 40 parts of best pale shellac; 12 parts of pulverized Florentine {439} lake; 30 parts gamboge; and 6 parts of dragon’s blood, likewise powdered, into a bottle and add 400 parts of spirit. Allow this mixture to form a solution preferably by heating the flask on the water bath, to nearly the boiling point of the water, and shaking now and then until all has dissolved. After the cooling pour off the liquid from the sediment, if any is present; this liquid constitutes a lacquer of dark-red color. In a second bottle dissolve in the same manner 24 parts of gamboge in 400 parts of spirit, which affords a lacquer of golden yellow color. According to the desired shade, the red lacquer is now mixed with the yellow one, thus producing any hue required from the deepest red to a golden tone. If necessary, thin with spirit of wine. The varnish is applied, as usual, on the somewhat warmed article, a certain temperature having to be adhered to, which can be ascertained by trials and is easily regulated by feeling.

II.—The following is equally suitable for boots and leather goods as for application on iron, stone, glass, paper, cloth, and other surfaces. The inexperienced should note before making this liquid that it does not give a yellowish bronze like gold paint, but a darkish iridescent one, and as it is a pleasing variation in aids to home decoration, it would doubtless sell well. Some pretty effects are obtained by using a little phloxine instead of part of the violet aniline, or phloxine alone will produce a rich reddish bronze, and a lustrous peacock green is obtained with brilliant aniline green crystals.

Quantities: Flexile methylated collodion, 1 gallon; pure violet aniline, 1 pound. Mix, stand away for a few days to allow the aniline to dissolve and stir frequently, taking care to bung down securely, as the collodion is a volatile liquid, then strain and bottle off. It is applied with a brush, dries rapidly, and does not rub off or peal.

«Celluloid Lacquer.»—Dissolve uncolored celluloid in a mixture of strong alcohol and ether. The celluloid first swells up in the solvent, and after vigorous shaking, the bottle is allowed to stand quietly for the undissolved portion to settle, when the clear, supernatant fluid is poured off. The latter may be immediately used; it yields a colorless glossy lacquer, or may be colored, as desired, with aniline colors.

«Colored Lacquer.»—Make a strong solution of any coloring matter which is soluble in methylated spirit, such as cochineal, saffron, the aniline dyes, etc. Filter through fine cambric, and to this filtered solution add brown shellac in flakes in the proportion of 4 to 5 ounces of shellac to each pint of methylated spirit. Shake once a day for about 8 days. If too thick it may be thinned by adding more colored spirit or plain spirit as required, and any lighter shade can be obtained by mixing with plain lacquer mixed in the above proportions. Lacquer works best in a warm, dry place, and the process is improved by slightly warming the articles, which must be absolutely free from grease, dirt, or moisture. The best results are obtained by applying many coats of thin, light-colored lacquer, each coat to be thoroughly dry before applying the next.

Apply with a soft camel’s-hair brush; it is better to use too small a brush than too large. When complete, warm the articles for a few seconds before a clear fire; the hotter the better; if too hot, however, the colors will fade. This makes the lacquer adhere firmly, especially to metallic surfaces. Aniline green works very well.

«Lacquer for Copper.»—A lacquer which to a certain degree resists heat and acid liquids, but not alkaline ones, is obtained by heating fine, thickly liquid amber varnish, whereby it is rendered sufficiently liquid to be applied with the brush. The copper article is coated with this and left to stand until the lacquer has dried perfectly. Next, the object is heated until the lacquer commences to smoke and turns brown. If the operation is repeated twice, a coating is finally obtained, which, as regards resisting qualities to acid bodies, excels even enamel, but which is strongly attacked even by weakly alkaline liquids.

«Ebony Lacquer.»—The ebony lacquer recommended by the well-known English authority, Mr. H. C. Standage, consists of 1⁠/⁠3 ounce aniline hydrochloride, 1⁠/⁠3 ounce alcohol, 1 part sulphate of copper, 100 parts of water. The aniline dye is dissolved in the alcohol and the copper sulphate in the water. The wood is first coated with the copper sulphate solution, and after this coating has been given plenty of time to dry the aniline salt tincture is applied. Shortly the copper salt absorbed by the wood will react on the aniline hydrochloride, developing a deep, rich black which acids or alkalies are powerless to destroy. Coat with shellac and give a French polish, thus bringing the ebony finish up to a durable and unsurpassed luster. {440}

«GOLD LACQUERS:»

I.—For Brassware.—A gold lacquer to improve the natural color of brassware is prepared from 16 parts gum lac, 4 parts dragon’s blood, and 1 part curcuma powder dissolved in 320 parts spirits of wine in the warmth and filtered well. The articles must be thoroughly cleaned by burning, grinding, or turning either dull or burnished, and then coated with a thin layer of the above mixture, applied with a soft hair brush or a pad of wadding. If the objects are colored the lacquer must be laid on by stippling. Should the color be too dark, it may be lightened by reduction with a little spirit until the correct shade is produced. The most suitable temperature for the metal during the work is about the warmth of the hand; if too hot or too cold, the lacquer may smear, and will then have to be taken off again with spirit or hot potash lye, the goods being dried in sawdust or recleaned as at first, before applying the lacquer again. Round articles may be fixed in the lathe and the lacquer laid on with a pad of wadding. In order to color brassware, a solution of 30 parts caustic soda; 10 parts cupric carbonate; 200 parts water (or 200 parts ammonia neutralized by acetic acid); 100 parts verdigris, and 60 parts sal ammoniac is employed, into which the warmed articles are dipped. After having dried they are coated with colorless shellac varnish.

II.—For Tin.—Transparent gold lacquer for tin (all colors) may be made as follows: Take 1⁠/⁠2 pint of alcohol, add 1 ounce gum shellac; 1⁠/⁠2 ounce turmeric; 1 1⁠/⁠4 ounce red sanders. Set the vessel in a warm place and shake frequently for half a day. Then strain off the liquor, rinse the bottle and return it, corking tightly for use. When this is used, it must be applied to the work freely and flowed on full, or if the work admits it, it may be dipped. One or more coats may be given as the color is required light or dark. For rose color substitute 1⁠/⁠4 ounce of finely ground lake in place of the turmeric. For blue, substitute Prussian blue. For purple, add a little of the blue to the turmeric.

For Bottle Caps, etc.—

I.—Gum gutta 10 parts Shellac 100 parts Turpentine 10 parts Alcohol 450 parts

II.—Gum gutta 40 parts Dragon’s blood 5 parts Alcoholic extract of sandalwood 5 parts Sandarac 75 parts Venice turpentine 25 parts Alcohol, 95 per cent 900 parts

Mix and dissolve by the aid of a gentle heat.

«Liquid Bottle Lac.»—Into a half-gallon bottle put 8 ounces of shellac, and pour over it 1 1⁠/⁠2 pints of alcohol of 94 per cent, and 2 1⁠/⁠2 ounces of sulphuric ether. Let stand, with occasional shaking, until the shellac is melted, and then add 4 ounces of thick turpentine and 1⁠/⁠2 ounce of boric acid. Shake until dissolved. To color, use the aniline colors soluble in alcohol—for red, eosine; blue, phenol blue; black, negrosin; green, aniline green; violet, methyl violet, etc. If it is desired to have the lac opaque, add 8 ounces of pulverized steatite, but remember to keep the lac constantly stirred while using, as otherwise the steatite falls to the bottom.

«Lithographic Lacquer.»—Dissolve 15 parts, by weight, of red lithol R or G in paste of 17 per cent, in 150 parts, by weight, of hot water. Boil for 2 minutes, shaking with 2.5 parts, by weight, of barium chloride. Dissolve in 25 parts, by weight, of water. Add to the mixture 100 parts, by weight, of aluminum hydrate of about 4 per cent. Cool, filter, and dry.

«Lacquer for Microscopes, Mathematical Instruments, etc.»—Pulverize 160 parts, by weight, turmeric root, cover it with 1,700 parts alcohol, digest in a warm place for 24 hours, and then filter. Dissolve 80 parts dragon’s blood, 80 parts sandarac, 80 parts gum elemi, 50 parts gum gutta, and 70 parts seed lac, put in a retort with 250 parts powdered glass, pour over them the colored alcohol first made, and hasten solution by warming in the sand or water bath. When completely dissolved, filter.

«To Fix Alcoholic Lacquers on Metallic Surfaces.»—Dissolve 0.5 parts of crystallized boracic acid in 100 parts of the respective spirit varnish whereby the latter after being applied forms so hard a coating upon a smooth tin surface that it cannot be scratched off even with the finger-nails. The aforementioned percentage of boracic acid should not be exceeded in preparing the solution; otherwise the varnish will lose in intensity of color.

«Lacquer for Oil Paintings.»—Dilute 100 parts of sulphate of baryta with 600 parts of water containing in solution 60 parts of red lithol R or G in paste of 17 {441} per cent. Boil the mixture for several minutes in a solution of 10 parts of barium chloride in 100 parts of water. After cooling, filter and dry.

«Lacquers for Papers.»—I.—With base of baryta: Dissolve 30 parts of red lithol R or G in paste of 17 per cent, in 300 parts of hot water. Add an emulsion obtained by mixing 10 parts of sulphate of alumina in 100 parts of water and 5 parts of calcined soda dissolved in 50 parts of water. Precipitate with a solution of 17.5 parts of barium chloride in 125 parts of water. Cool and filter.