Let a 1/4 lb. of india-rubber, in small pieces, soften in 1/2 lb. of oil of turpentine, then add 2 lbs. of boiled oil, and boil for 2 hours over a slow fire. When dissolved, and 6 lbs. of boiled linseed oil, and 1 lb. of litharge, and boil until an even liquid is obtained. Applied warm.
Dissolve 2 1/2 oz. of shellac in a pint of rectified spirits of wine; boil for a few minutes with 5 oz. of well-burnt and recently - heated animal charcoal. A small portion of the solution should then be filtered, and if not colourless, more charcoal added; when all the colour is removed, press the liquor through a piece of silk, and afterwards filter through fine blotting paper. This kind of varnish should be used in a room at 60° Fahr., perfectly free from the least dust. It dries in a few minutes, and is not liable afterwards to chill or bloom. It is particularly applicable to drawings and prints that have been sized, and may be advantageously used upon oil paintings which are thoroughly hard and dry, as it brings out the colours with the purest effect.
1. Melt in an iron pan at a slow heat, copal gum, powdered, 8 parts, and add balsam capivi, previously warmed, 2 parts. Then remove from the fire, and add spirits of turpentine, also warmed beforehand, 10 parts, to give the necessary consistence. Gum copal is made more soluble in spirits of turpentine by melting the powdered crude gum, and allowing it to stand for some time loosely covered. 2. Pounded copal, 24 parts; spirits of turpentine, 40; camphor, 1. 3. Copal in powder, 16 parts; camphor, 2; oil of lavender, 90. Dissolve the camphor in the oil, heat the latter, and stir in the copal in successive portions until complete solution takes place. Thin with sufficient turpentine to make it of proper consistence. 4. Coarsely-powdered copal and glass, of each 4 oz.; alcohol of 90 per cent., 1 pint; camphor, 1/2 oz.; heat it in a water bath so that the bubbles may be counted as they rise, observing frequently to stir the mixture; when cold decant the clear. Used for pictures. 5. Copal melted and dropped into water, 3 oz; gum sanda rach, 6 oz.; mastic and Chio turpentine - of each 2 1/2 oz.; powdered glass, 4 oz.; alcohol of 85 per cent., 1 quart; dissolve by a gentle heat.
Used for metal, chairs, etc.
4 oz. copal, 1/2 oz. camphor, 3 oz. white drying oil, 2 oz. essential oil of turpentine. Reduce the copal to powder, mix the camphor and drying oil, then heat it on a slow fire, and add the oil of turpentine, and strain.
Best black sealing wax, 1/2 oz.; rectified spirits of wine, 2 oz.; powder the sealing wax, and put it with the spirits of wine into a phial, digest them in a sand bath, or near a fire till the wax is dissolved; lay on warm with a fine soft hair-brush before a fire, or in the sun.
Gum dammar, 10 parts; gum sandarach, 5; gum mastic, 1. Digest at a low heat, occasionally shaking with spirits of turpentine, 20 parts. Add spirits of turpentine until of the consistence of syrup.
1. Take bleached shellac, pounded in a mortar; place the bruised fragments into a bottle of alcohol until some shellac remains undissolved; agitate the bottle and contents frequently, and let the whole stand till clear; pour off the clear fluid. This forms the varnish. Warm the metal surface and coat with a camel-hair brush. If not perfectly transparent, warm the varnished surface before a fire or in an oven until it becomes clear. Common orange shellac answers equally well, and for large surfaces even better, as it is more soluble than the bleached variety, and coats more perfectly, but care must be taken not to use the varnish insufficiently diluted.
2. Digest 1 part of bruised copal in 2 parts of absolute alcohol; but as this varnish dries too quickly it is preferable to take 1 part of copal, 1 part of oil of rosemary, and 2 or 3 parts of absolute alcohol. This gives a clear varnish as limpid as water. It should be applied hot, and when dry it will be found hard and durable. 3. Mix equal quantities of Canada balsam with very clear spirits of turpentine, until the whole is of the consistency of ordinary varnish, which can be determined by constantly shaking and allowing to settle. This may be applied without warming the varnish or the metal.
Gum elemi, 30 parts; white amber, 45; charcoal 30; spirits of turpentine, 375. Used in a heated state; the metal to which it is to be applied being also heated.
Dissolve 10 parts of clear grains of mastic, 5 camphor, 15 sandarach, and 5 of elemi, in a sufficient quantity of alcohol, and apply without heat.
Spirits of turpentine, 6 oz.; asphaltum, 2 oz.; white wax, 2 scruples; lampblack, 1 1/2 scruple. Dissolve in a warm place, and filter through flannel.
1. Begin at the corner of the print by rubbing up the varnish with the fingers; a fine white dust will be produced, which is the dry old varnish; proceed all over the print and wipe off this white dust with a rag. Repeat until the print has lost most or all of the old varnish. Now strain the print on a drawing board, size with weak parchment size; when dry size again with the same size; use the size half chilled; when perfectly dry apply mastic or other varnish. 2. Lay blotting paper on the print, and saturate with pure spirit, which will dissolve and the blotting paper absorb the varnish. Change the blotting paper, and repeat as often as may be needful.