VARNISH 1057 



of doors, or into another building where there is, no fire, and mix with it three gallons 

 of turpentine ; afterwards strain it, and put it aside for use. This, if properly boiled, 

 will dry in ten minutes ; but if too strongly boiled, will not mix at all with the tur- 

 pentine ; and sometimes, when boiled with the turpentine, will mix, and yet refuse to 

 incorporate with any other varnish less boiled than itself: therefore it requires a nicety 

 which is only to be learned from practice. This varnish is chiefly intended for the 

 use of japanners, cabinet-painters, coach-painters, &c. 



Best-body Co-pal Varnish, for coach-makers, $c. This is intended for the body parts 

 of coaches and other similar vehicles, intended for polishing. 



Fuse 8 Ibs. of fine African gum copal ; add two gallons of clarified oil (old measure) ; 

 boil it very slowly for four or five hours, until quite stringy ; mix with three gallons 

 and a half of turpentine ; strain off, and pour it into a cistern. As they are too slow 

 in drying, coach-makers, painters, and varnish-makers have introduced to two pots of 

 the preceding varnish one made as follows : 



8 Ibs. of fine pale gum anime ; 3 gallons of turpentine. 



2 gallons of clarified oil ; To be boiled four hours. 



The more minutely the gum copal is run, or fused, the greater the quantity, and the 

 stronger the produce. The more regular and longer the boiling of the oil and gum 

 together is continued, the more fluid or free the varnish will extend on whatever it is 

 applied to. When the mixture of oil and gum is too suddenly brought to string by too 

 strong a heat, the varnish requires more than its just proportion of turpentine to thin 

 it, whereby its oily and gummy quality is reduced, which renders it less durable ; 

 neither will it flow so well in laying on. The greater proportion of oil there is used 

 in varnishes, the less they are liable to crack, because the tougher and softer they are. 

 By increasing the proportion of gum in varnishes, the thicker will be the stratum, the 

 firmer they will set solid, and the quicker they will dry. When varnishes are quite 

 new made, and must be sent out for use before they are of sufficient age, they must 

 always be left thicker than if they were to be kept the proper time. Varnish made 

 from African copal alone possesses the most elasticity and transparency. Too much 

 drier in varnish renders it opaque and unfit for delicate colours. Copperas does not 

 combine with varnish, but only hardens it. Sugar of lead does combine with varnish. 

 Turpentine improves by age ; and varnish by being kept in a warm place. All copal - 

 or oil-varnishes require age before they are used. 



All body- varnishes are intended and ought to have \\ Ib. of gum to each gallon of 

 varnish, when the varnish is strained off and cold; but as the thinning up, or quantity 

 of turpentine required to bring it to its proper consistency, depends very much upon 

 the degree of boiling the varnish has undergone, therefore, when the gum and oil 

 have not been strongly boiled, it requires less turpentine for that purpose ; whereas, 

 when the gum and oil are very strongly boiled together, a pot of 20 gallons will 

 require perhaps 3 gallons above the regular proportionate quantity ; and if mixing 

 the turpentine be commenced too soon, and the pot be not sufficiently cool, there will 

 be frequently above a gallon and a half of turpentine lost by evaporation. 



Pale Amber Varnish. Fuse 6 Ibs. of fine picked very pale transparent amber in 

 the gum-pot, and pour in 2 gallons of hot clarified oil. Boil it until it strings very 

 strong. Mix with 4 gallons of turpentine. This will be as fine as body-copal, will 

 work very free, and flow well upon any work it is applied to : it becomes very hard, 

 and is the most durable of all varnishes. 



Fine Mastic, or Picture Varnish. Put 5 Ibs. of fine picked gum mastic into a 

 new 4-gallon tin bottle ; get ready 2 Ibs. of glass, bruised as small as barley ; and 

 put it into the bottle with 2 gallons of turpentine that has settled some time ; put a 

 piece of soft leather under the bung ; lay the tin on a sack upon the counter, table, or 

 anything that stands solid ; begin to agitate the tin, smartly rolling it backward and 

 forward, causing the gum, glass, and turpentine, to work as if in a barrel-churn for at 

 least 4 hours, when the varnish may be emptied out. If the gum is not all dissolved, 

 return the whole into the bottle, and agitate as before, until all the gum is dissolved ; 

 then strain it through fine thin muslin into a clean tin bottle : leave it uncorked, so 

 that the air can get in, but no dust ; let it stand for nine months at least before it is 

 used, for the longer it is kept the tougher it will be, and less liable to chill or bloom. 



Common Mastic Varnish. Put as much gum mastic, unpicked, into the gum-pot as 

 may bo required, and to every 2f Ibs. of gum pour in 1 gallon of cold turpentine ; 

 set the pot over a very moderate fire, and stir it with the stirrer ; be careful, when the 

 steam of the turpentine rises near the mouth of the pot, to cover it with the carpet, 

 and carry it out of doors, as the vapour is very apt to catch fire. A few minutes' 

 low heat will perfectly dissolve 8 Ibs. of gum, which will, with 4 gallons of 

 turpentine, produce, when strained, 4^ gallons of varnish ; to which add, while yet 



Vot. III. 3 Y 



