(2) There are 2 kinds of Brunswick 3 black - viz., best and common. The way the best is manufactured is as follows:- In an iron boiler, over a slow furnace, 90 lb. foreign asphaltum is boiled for about 13 hours, and at the same time 12 gal. boiled oil is re - boiled for 13 hours. During the boiling of the oil, about 12 lb. litharge is gradually introduced, and boiled until it becomes stringy. The boiler containing the oil is then emptied into the boiler containing the asphaltum. They are both boiled together until, upon trial, the mixture will roll into hard pills. The mass is then cooled, and mixed with 50 gal. turpentine. Common Brunswick black is made as follows:- 112 lb. common black pitch and 112 lb. common asphaltum made from tar are put in an iron boiler, and boiled for 32 or 40 hours, by which time the gas and moisture will have evaporated. It remains standing for 2 nights, and on the third morning is re - boiled. As soon as it boils, 32 gal. boiled oil are added; then 40 lb. red - lead and 40 lb. litharge are gradually introduced, and boiled for 12 hours, or until it will roll very hard. When ready for mixing, 80 gal. turpentine are introduced, until the whole mass is of a proper consistency.
This will dry in 1/2 hour, if properly boiled. (Crawford.)
Into a large - mouthed bottle, Ayres puts 500 gr. methylated alcohol, and 90 to 100 gr. pulverized gum lac. In another similar bottle he dissolves 90 to 100 gr. powdered bitumen in 500 gr. benzine. Shaking the bottles frequently, the solution is complete at the end of 2 or 3 days. The 2 solutions are mixed in equal proportions, and thickened to the consistency of cream with finely pulverized charcoal. It may be rendered more fluid, if required, by adding the proper quantity of a mixture of equal parts of alcohol and benzine. (Soc. Franc. Photog.)
Each gum is dissolved separately in 5 pints alcohol, and the annatto and saffron are separately infused in a like quantity of alcohol. The ingredients are mixed to form any particular tint desired. Turmeric (ground), 1 lb.; alcohol, 2 gal.; macerate for one week, ■train by expression, and add gamboge, 1 1/2 oz.; pale shellac, 3/4 lb.; gum san - darach, 3 1/2 lb. Strain, and add turpentine varnish, 1 qt. Other lacquers are prepared in a similar way from alcohol and shellac, a solution of the colouring ingredients, as dragon's blood, gamboge, etc, being kept on hand, and added to produce any required tint. (3) 2 parts seed - lac, 4 sandarach, 4 elemi, 40 alcohol. Alcoholic solutions of gamboge and dragon's blood, or fnchsin, picric acid, Martin's yellow, and coralline, are separately prepared, and added to the above in quantities ascertained by trial to impart the desired colour. To remove the marks left by the brush, and to impart lustre, the varnish, after drying, is polished. This is effected by first rubbing with powdered pumice and water, and next with an oiled rag and tripoli, until the desired polish is produced; the surface is afterwards dried with a soft linen cloth; any greasiness is removed by means of powdered starch, and the process is finished by rubbing with the hand.
Great care must be taken that the surface to which varnish is applied be free from grease or smoke, which prevents all oil - varnish from drying. (4) Turmeric, 1 dr.; gamboge, 1 dr.; oil of turpentine, 2 pints; shellac, 5 oz.; gum sandarach, 5 oz.; dragon's blood, 7 dr.; thin mastic varnish, 8 oz. Digest with occasional agitation for 14 days in a warm place, then set aside to fine, and pour off the clear. (5) Dissolve gum lac in spirits of wine. (6) 1 lb. ground turmeric, 1 1/2 oz. ground gamboge, 3 lb. ground gum sandarach, 1 lb. ground shellac (bleached), 2 gal. alcohol, 3 pints turpentine varnish. Put the whole into a suitable vessel, cork close, and agitate until dissolved. (7) 1 gal. methylated spirits of wine, 10 oz. seed - lac bruised, and 1/2 oz. red sanders; dissolve and strain. (8) A gold lac, remark-able for its great hardness and beautiful colour, on being analysed by Dr. R. Kayser at Nuremberg, gave as its constituents picric acid and boracic acid. Thereupon a clear shellac solution was mixed with picric acid and about 1/2 Per cent. crystallized boracic acid, each being previously dissolved in alcohol, and the resulting lac possessed all the advantages of the former one.
(1) A black varnish, splendid in tone on steel or iron, is produced by turpentine and sulphur boiled together, laid on with a brush. The evaporation of the turpentine leaves a thin layer of sulphur, which unites with the iron when heated a short time over a gas or spirit flame. The varnish is durable and perfect. (2) 2 gal. spirits of wine, 1 lb. fine pale shellac; add to the above 3 oz. Cape aloes cut small, and 1 oz. gamboge cut small. Those who make lacquers frequently want some paler and some darker, and sometimes inclining more to the particular tint of certain of the component ingredients. Therefore if a 4 - oz. phial of a strong solution of each ingredient be prepared, a lacquer of any tint can be produced at any time. (3) For cast - iron pipes use ordinary as - phalte. Have a long cast tank set up on a small furnace underground. As - phalte is melted in it in sufficient quantity to entirely cover the pipe outside and inside, which is left in long enough to become the same temperature as the asphalte, then lifted out and well drained by holding the pipe vertically; a.wooden cover keeps in the heat, and forms an extinguisher should the asphalte catch fire by overheating. (4) For hot - water pipes, lime or whiting whitewash mixed with size is a good varnish for protecting pipes; but nothing it better than blackleading, if appearance counts for anything.