the necessary coats of paint have been put on to the wood a ground is then laid of the required tint and left to dry. The painter then prepares small quantities of the same colour with a little brown, and boiled oil and turpentine, and, having mixed this, spreads it over some small part of his work. The flat hogs’ hair brushes being dipped in the liquid and drawn down the newly-laid colour, the shades and grainings are produced. To obtain the mottled appearance the camels’ hair pencils are applied, and when completed the work is left to dry, and afterwards covered by a coat or two of good copal varnish. Imitation wainscot requires the use of combs of various degrees of fineness to obtain the grain (whence the process is called combing by some persons), and the flower is got by wiping off the colour with a piece of rag. When dry it is over-grained to obtain a more complete representation of the natural wood, and then varnished. If the work be done in water-colour and not in oil, beer grounds to act as a drier are mixed with the colour; this sets it ready for varnishing. A “patent graining machine,” a sort of roller with a pattern upon it, is often used.
Marbling.—Marbling is the imitation of real marbles and granites, some of which are represented by splashing on the carefully prepared ground, which should have been painted and often rubbed and polished to obtain an even surface; others have to be painted in colours, and then well varnished.
Painting on Plaster Work.—Plastering should never be painted until it is thoroughly dry. Portland cement is best left for a year or two before being painted. Plaster work not previously painted will require four or five coats, Portland cement five or six. If plastered work is required to be painted immediately, it should be executed in Keene’s or Parian cement (see Plaster Work). A great deal more paint is of course absorbed by plaster than by wood, just as wood absorbs more than iron.
Painting on Iron.—Iron and steel work should receive a coat of oxide paint at the manufacturer’s works; additional coats are added after erection. All rust should be previously removed by means of wire brushes and paraffin or turpentine. The best paints for external iron work are composed of oxide of iron and red lead, mixed with linseed oil.
The following is an extract from the building by-laws of the municipality of Johannesburg:—
“All structural metal work shall be thoroughly cleaned from scale and rust before painting. Faying surfaces in riveted work shall be painted before putting them together. All surfaces of steel or iron work inaccessible after erection shall be protected as far as possible either by coating them with ‘Smith’s ’ or other approved bituminous composition, or by filling the spaces which they enclose with lime concrete.”
Repainting Old Work.—Before beginning to repaint work of any description it must be thoroughly cleaned. If the surface is in good condition it will be sufficient to scrub down with good soap and water and afterwards sponge and wipe dry. If the work has become rough it will often be necessary to use pumice stone to facilitate the operation of cleaning. The pumice should be cut or rubbed to a flat surface and vigorously applied with plenty of clean water. It is essential that the work should be quite dry before any paint is applied. If the old surface is much cracked and blistered no amount of rubbing with pumice will enable the workman to obtain a good ground for the new coats, and it will be necessary to remove the old paint entirely. For this purpose painters most frequently use a paint burner or torch which burns paraffin oil under air pressure. This causes the paint to soften and blister under the heat, in which state it is readily scraped off by a blunt knife. The old-fashioned grate filled with charcoal held close to the surface by means of a long handle is now not often used. There has recently been a considerable increase in the use of chemical paint removers in paste or liquid form; as a rule these contain some alkali, such as lime or caustic soda. The preparation is brushed on to the paint required to be removed, and in the course of from ten minutes to half an hour the paint becomes so soft that it can readily be scraped off.
Blistering and Cracking.—The blistering of painted surfaces may be caused in several ways. If on iron, it may be the result of a particle of rust which, not having been removed in the process of cleaning, has increased in size and loosened the paint. If on plaster, a particle of unslaked lime may have “blown,” with a similar result. On wood, blistering is usually caused by painting upon a wet surface or upon unseasoned wood. Blisters may also be caused by the use of too much oil in paint exposed to heat, or the application of one coat upon another before the latter is properly dry. To prevent blistering a method that has been tried with good results is to apply two coats of water paint (washable distemper) and follow by two coats of oil colour or varnish. Cracking is caused by the use of too much oil in the under coats and too little in the top coats.
Distemper.—New plaster-work must be quite dry before distemper is applied. The work should be stopped (that is, any irregularities filled up with plaster of Paris mixed with whiting and water to a paste) and then rubbed perfectly smooth with glass paper. Clairecole, a solution of thin size and whiting, is then applied to render the plaster non-absorbent, and this is followed by distemper of the desired colour. Distemper is made by soaking whiting in clean water to a creamy consistency. To this is added size which has been previously warmed, and the pigment required to colour the mixture; the whole is then well stirred and strained to remove any lumps. Many patent washable distempers under fancy names are now on the market in the form of paste or powder, which simply require to be mixed with water to be ready for use. If applied to woodwork distemper is apt to flake off.
The “one-knot” brush for cornices and other mouldings and the “two-knot” and “brass-bound” brushes for flat surfaces are usually employed for distempering and whitewashing.
A granular surface is produced by stippling or dabbing the surface with a stiff bristled brush specially made for this purpose.
Gilding, &c.—Very rich effects may be produced both in external and internal decorations by the judicious use of overlays of gold or silver. In their application, however, it must always be borne in mind that they are metals, not paints, and they should only be used in positions such as would be appropriate for the actual metals. “Dutch metal” and other imitations cost about one-third of the price of genuine gilding, and require to be protected from oxidization by a coat of lacquer. Gold leaf is affixed with gold size or other adhesive preparations. The best and most durable work is oil gilding, which involves less labour, and results in a richer appearance than other methods. The work is usually primed first of all with a solution of boiled linseed oil and white lead, and then covered with a fine glutinous composition called gold size, on which, when it is nearly dry, the gold leaf is laid in narrow strips with a fine brush, and pressed down with a pad of cotton-wool held in the fingers. As the slips must be made to overlap each other slightly to ensure the complete covering of the whole surface, the loose edges will remain unattached, to be afterwards struck off with a large sable or camel-hair brush. The joints, if the work be skilfully executed, will be invisible. For burnished gilding the work must be covered with various coats of gluten, plaster and bole, which last is mixed with gold size to secure the adhesion of the leaf.
Authorities.—A. C. Wright, M.A., B.Sc., Simple Methods for Testing Painters’ Materials; Professor A. H. Church, Colour; Ellis A. Davidson, House Painting, Graining, Marbling and Sign Writing; W. J. Pearce, Painting and Decorating; A. S. Jennings, Paint and Colour Mixing; G. H. Hurst, F.C.S., Painters, Colours, Oils and Varnishes. (J. Bt.)
PAINTING, in art, the action of laying colour on a surface, or the representing of objects by the laying of colour on a surface. It is with painting in the last sense, considered as one of the fine arts, that this article deals. In the first sense, in so far as painting is a part of the builder’s and decorator’s trade it is treated above under the heading Painter-Work. The verb “to paint” is derived through Fr. peindre (peint, the past participle, was possibly the earliest part adopted, as is suggested
