43* 



MECHANICAL. 



turn, previously mixed with the cold oil, 

 and afterwards heated very hot; mix well, 

 remove the vessel from the fire, and when 

 cooled a little add the turpentine, also 

 made warm. 



Each of the above varnishes should be 

 reduced to a proper consistence with 

 more turpentine if required. The last 

 form produces the beautiful black varnish 

 used by the coach-makers. Some man- 

 ufacturers omit the whole or part of the 

 asphaltum, and use the same quantity 

 of clear black resin instead, in which 

 case the color is brought up by lampblack 

 reduced to an impalpable powder, or pre- 

 viously ground very fine with a little 

 boiled oil. The varnish made in this 

 way, lacks, however, that richness, bril- 

 liancy, and depth of blackness imparted 

 by asphaltum. 



VARNISH, Amber, Pale.— a. Amber 

 pale and transparent, six pounds; fuse, 

 add hot clarified linseed oil, two gallons ; 

 boil till it strings strongly, cool a little, 

 and add oil of turpentine four gallons. 

 Pale as copal varnish; soon becomes 

 very hard, and is the most durable of 

 oil varnishes; but requires time before 

 it is fit for polishing. When wanted to 

 dry and harden quickly, drying oil may 

 be substituted for linseed, or "driers" 

 may be added during the boiling. 



b. Amber, one pound ; melt, add Scio 

 turpentine, one-half pound; transparent 

 white resin, two ounces ; hot linseed oil, 

 one pint, and afterwards oil of turpen- 

 tine as much as sufficient, as above. Very 

 tough. 



c. Hard — Melted amber, four ounces; 

 hot boiled oil, one quart, as before. 



d. Fale — Very pale and transparent 

 amber, four ounces ; clarified linseed oil 

 and oil of turpentine, of each one pint, as 

 before. 



Amber varnish is suited for all pur- 

 poses, where a very hard and durable 

 oil varnish is required. The paler kind 

 is superior to copal varnish, and is often 

 mixed with the latter to increase its hard- 

 ness and durability. 



VARNISH, Black, for Iron-Work.— 

 Asphaltum, forty-eight pounds ; fuse, add 

 boiled oil, ten gallons ; red lead and li- 

 tharge, of each seven pounds ; dried and 

 powdered white copperas, three pounds; 

 boil for two hours, then add dark-gum 

 amber (fused), eight pounds ; hot linseed 



oil, two gallons ; boil for two hours lon- 

 ger, or till a little of the mass, when cool- 

 ed, may be rolled into pills, then with- 

 draw the heat, and afterwards thin down 

 with oil of turpentine, thirty gallons. 

 Used for the iron work of carriages, and 

 other nice purposes. 



VARNISH, Black.— Heat to boiling 

 linseed oil varnish, ten parts, with burnt 

 umber, two parts, and powdered asphal- 

 tum, one part, and when cool dilute with 

 spirits of turpentine to the required con- 

 sistence. 



VARNISH, Black, for Wood.— There 

 are two kinds of black varnish : 



a. The ordinary black varnish foi dif- 

 ferent kinds of wood. 



b. The black ebony varnish for certain 

 woods which approach nearest to ebony 

 in hardness and weight. 



The ordinary black wood varnish is ob- 

 tained by boiling together blue Brazil 

 wood, powdered gall apples and alum, in 

 rain or river water, until it becomes 

 black. This liquid is then filtered through 

 a fine organzine, and the objects painted 

 with a new brush before the decoction 

 has cooled, and this is repeated until the 

 wood appears of a fine black color. It is 

 then coated with the following varnish : 

 a mixture of iron filings, vitriol and vine- 

 gar is heated (without boiling), and left a 

 few days to settle. If the wood is black 

 enough, yet for the sake of durability, it 

 must be coated with a solution of alum 

 and nitric acid, mixed with a little verdi- 

 gris ; then a decoction of gall apples and 

 logwood dyes is used to give it a deep 

 black. A decoction may be made of 

 brown Brazil wood with alum in rain wa- 

 ter, without gall apples ; the wood is left 

 standing in it for some days in a moder- 

 ately warm place, and to it merely iron 

 filings in strong vinegar are added, and 

 both are boiled with the wood over a 

 gentle fire. For this purpose soft pear 

 wood is chosen, which is preferable to alL 

 others for black varnishing. 



For the fine black ebony varnish, ap- 

 ple, pear, and hazlewood are recommend- 

 ed in preference for this; especially 

 when these kinds of wood have no 

 projecting veins, they may be success- 

 fully coated with black varnish, and 

 are then most complete imitation of 

 the natural ebony. For this varnish : 

 fourteen ounces of gall apples, three and 



