Bottles, or other glass vessels, which it is desired to make impervious to light, may be co&ted according to Ferd. Simand, with a black lacquer prepared in the following manner. Equal (arts of asphalt and of boiled linseed-oil are heated for one hour, over a naked fire to about 200° C. (392° F.); then a sufficient quantity of lamp-black, previously triturated with oil of turpentine, is added, to make a mixture, which, when mixed with 1/4-1/3 its volume of oil of turpentine, will cover well. Usually, one coat is sufficient; in special cases, two coats may be required. Sometimes it is desirable to be able to see the height at which the liquid in the bottle is standing. This may be accomplished, according to the author, by leaving a small round spot on opposite sides un-coated. The bottom of the bottle is likewise left unvarnished. It would be better to leave a very narrow vertical streak, on the side of the bottle usually turned towards the wall, uncoated.
This would more readily permit ascertaining at what level the liquid stands. (New Remedies.)
(15) When properly lacquered, brass work will retain its colour, and resist the action of the atmosphere for a long time; hence the necessity of always lacquering work which should retain a good appearance. The process is rather difficult to execute properly, especially on large, surfaces, where the tyro will find the lacquer continually getting a smeary look. Before applying the lacquer, the brass must be heated to a certain degree, and the difficulty is to know the exact degree best suited to the particular lacquers and materials used, and the effect to be produced; this kind of knowledge cannot be attained but by experience. If you do not feel disposed to prepare the surfaces of your work by means of filing, etc, another plan, far easier and equally effective, though not producing such a workmanlike job, is the following: - Put the brass work, having previously taken it to pieces as much as possible, into pickle made of nitric acid and water; this will eat away the outer ccat, all the corrosion, and all lacquer, leaving a surface of pure brass. The time required to effect this and the strength of the pickle can -be soon ascertained by trial. The work must be carried on in the open air, as the fumes given off arc very baneful to health.
Thoroughly wash the articles to remove all traces of acid, and then dry them in hot sawdust; they will then be ready for lacquering. Use a camel-hair brush to lay on the lacquer with, heat the articles as hot as may be held in the hand; be careful not to touch the bright surface with anything that will stain it, and lay on the lacquer as thinly as possible to prevent smears. If the work is too hot it will burn the lacquer, and if too cold this will not set hard. Small thin articles part with a large proportion of their heat in laying on the lacquer, but bulky work is comparatively unaffected; so small articles must be made somewhat hotter than large before lacquering. Only experience will enable you to judge correctly.
(16) Lacquer is so called because it usually contains gum lac, either shellac or seed lac. Seed lac is the original form of the gum or resin; after being purified it is moulded into thin sheets, like shell, and hence is called shellac. Shellac is frequently bleached so as to become quite white, in which state it forms a colourless solution. Bleached shellac is never as strong as the gum in its natural condition, and unless it be fresh it neither dissolves well in alcohol nor does it preserve any metal to which it may be applied. There are many recipes for good lacquer, but the success of the operator depends quite as much upon skill as upon the particular recipe employed. The metal must be cleaned perfectly from grease and dirt, and in lacquering new work it is always best to lacquer as soon after polishing as possible. Old lacquer may be removed with a strong lye of potash or soda, after which the work should be well washed in water, dried in fine beech or boxwood sawdust, and polished with whiting applied with a soft brush. The condition of the work, as to cleanliness and polish, is perhaps the most important point in lacquering. The metal should be heated and the lacquer applied evenly with a soft camel-hair brush. A temperature of about that of boiling water will be found right.
The solution of lac or varnish is colored to suit the requirements or taste of the user.
(17) A good pale lacquer consists of 3 parts Cape aloes and 1 of turmeric to 1 simple lac varnish. A full yellow contains 4 turmeric and 1 annatto to 1 lac varnish. A gold lacquer, 4 dragon's-blood and 1 turmeric to 1 lac varnish. A red, 32 parts annatto and 8 dragon's-blood to 1 lac varnish. A great deal depends, also, upon the depth of color imparted to the lacquer, and as this may require to be varied, a very good plan is to make up a small stock bottle, holding, say, 1/2 pint, according to any good recipe, and add as much of it to the varnish as may be required for the desired tint.
(18) Deep Gold Lacquer
Alcohol, 1/2 pint; dragon's-blood, 1 dr.; seed lac, 1 1/2 oz.; turmeric, 1/4 oz. Shake up well for a week, at intervals of, say, a couple of hours; then allow to settle, and decant the clear lacquer; and if at all dirty filter through a tuft of cotton wool. This lacquer may be diluted with a simple solution of shellac in alcohol, and will then give a paler tint.
(19) Bright Gold Lacquer
(a) Turmeric, 1 oz.; saffron 1/4 oz.; Spanish annatto, 1/4 oz.; alcohol 1 pint. Digest at a gentle heat for several days; strain through coarse linen; put the tincture in a bottle and 3 oz. good seed lac coarsely powdered. Let it stand for several days, shaking occasionally. Allow to settle, and use the clear liquid.
(6) 1 oz. annatto and 8 oz. alcohol; mix in a bottle by themselves. Also mix separately 1 oz. gamboge and 8 oz. alcohol. With these mixtures color seed lac varnish to suit yourself. If it be too red, add gamboge; if too yellow, add annatto; if the color be too deep, add spirit. In this manner you may colour brass of any desired tint.
(20) Pale Gold Lacquer
Best pale shellac (picked pieces), 8 oz.; sandarac, 2 oz.; turmeric, 8 oz.; annatto, 2 oz.; dragon's-blood, 1/4 oz.; alcohol, I gal. Mix, shake frequently till the gums are dissolved and the color extracted from the colouring matters, and then allow to settle.
(21) 4 oz. shellac and 1/4 oz. gamboge are dissolved by agitation, without heat, in 24 oz. pure pyro-acetic ether. The solution is allowed to stand until the gummy matters, not taken up by the spirit, subside. The clear liquor is then decanted, and when required for use is mixed with 8 times its quantity of alcohol. In this case the pyro-acetic ether is employed for dissolving the shellac in order to prevent any but the purely resinous portions being taken up, which is almost certain to occur with ordinary alcohol; but if the lacquer were made entirely with pyro-acetic ether, the latter would evaporate too rapidly to allow time for the lacquer to be equally applied. (Workshop Companion.)