Black Varnishes.

Scientific American 3, 5.2.1848

For the Scientific America.

BLACK JAPAN.

Set in a pot 48 pounds of asphaltum and as soon as it is melted pour in 10 gallons of linseed oil, raw. Keep a moderate heat. Fuse 8 pounds of gum anima in a gum pot mixed with 2 gallons of hot oil and then pour this into the set pot. Afterwards fuse 10 pounds of dark sea amber in another pot and keep stirring it while fusing with and whenever it appears to be overheating lift off the pot for a few minutes. When this is completely fused mix in 2 gallons of hot oil and pour it into the set pot also and continue the boiling for three hours longer and mix red lead for a drier. Take it off when this is incorporated, let it cool and add turpentine to working consistency.

BRUNSWICK BLACK

Put 28 pounds of common pitch and 28 pounds of asphaltum made from gas tar into an iron pot and boil both for 5 or 10 hours to evaporate gas and moisture. Then add gradually to it l0 pounds of litharge and 10 pounds of red lead and boil for three hours until it will roll hard. When it is cool add turpentine to working consistency. This is for engineers and founders and will dry very quick. A better kind is made by putting 45 pounds of good asphaltum in an iron pot over a slow fire for 6 hours. Into another pot boil 6 gallons of boiled linseed oil into which is added slowly 6 pounds of litharge until it feels stringy between the fingers, then pour it gradually into the pot with the asphaltum and let the mixture boil until when taking it out, it will roll hard, when it must be left to cool and then the turpentine may be added to working consistency.

BLACK VARNISH for the iron work of carriages.

Put 48 pounds of native bitumen (asphaltum) in an iron pot and boil 4 hours.—During the first two hours introduce 7 pounds of red lead, 7 pounds of litharge, 3 pounds of dried copperas and add 1 pound of coarse gum and 12 gallons of boiled oil and continue the boiling. Test it like the previous process when in like manner it is prepared for use by the turpentine. Black varnish for leather, such as that made for boots and shoes and carriage leather is made, by diseolving shellac in alcohol and mixing a proper quantity of ivory black, or lampblack for a coarser kind, and it may be diluted with water to working consistency to be applied with a piece of sponge.