The Process of Painting.
Supposing the carpenter to have left the doors, the windows, &c., in a clean and smooth state, the painter’s first office is knotting. Knots are round places in a plank, in which the grain of the wood runs through the thickness of the board, so as to show the ends of the pores at the surface. These ends absorb a greater quantity of paint than the other portion of the wood, so that if the same number of coats were given to all alike, the knots would have an ugly, dead appearance, in consequence of the absorption. The painter, therefore, gives the knots more paint than the rest of the wood-work; and the preparatory coat, which is laid on the knots only, is called the knotting. The paint used is generally red lead, and boiled oil; or sometimes red lead and size. When this knotting is dry, the priming is applied, consisting of a thin coat of white paint. White is used for the priming under almost every variety of circumstances, whatever the subsequent colours may be. This white paint is a mixture of white lead, linseed oil, and oil of turpentine, and is laid on, as are the subsequent coats, by means of brushes which are too well known to need a lengthened description. They vary from a quarter of an inch to three inches in diameter, and are generally made of hog’s bristles bound round with string, or sometimes with tin.
When the priming is dry, the painter proceeds to fill up all the nail holes and other irregularities, with putty. This he does by means of a pointed knife, with which he works in small portions of putty wherever they may be needed. It is then ready for the second coat of paint, which is thicker than the first, generally white, but sometimes coloured. Painting appears to be a very easy process, but in common with other trades, it requires considerable practice before skill can be attained. After having worked the brush over the wood-work in every direction, so as to completely cover every part with paint, the “laying-off” is effected by drawing the brush smoothly over every part in the direction of the grain, particularly at the stiles and panels of doors. Brushes of various sizes are employed, by means of which the workman can paint the fine mouldings, beading, &c., as well as the broader surfaces. The more skilful the workman is in the use of his tools, the less do the marks of the brush remain visible when the work is done.
As each coat of paint dries, another is laid on, until sufficient has been applied. The number varies from two to seven, according to the part which is to be painted, and the means of those who have to pay the painter; but in general, four coats is the average quantity which new wood-work receives. It is the last two coats only which are of the colour selected, as those which are preparatory are seldom other than white. On some occasions it is desired to have the last coat glossy; but in others dead. To effect these differences, all that is necessary is, to vary the oil with which the colour is mixed. If a glossy surface is required, linseed oil is principally used; but if a dead surface, oil of turpentine predominates. It is frequently seen that the walls of staircases, and other large surfaces, are, when finished painting, totally without gloss. This is effected by what is called flatting, that is, a coat of paint mixed wholly with oil of turpentine: the turpentine soon evaporates, and leaves the colour without gloss on the walls; whereas, when linseed oil is employed, the oil dries and hardens, instead of evaporating, and assumes much of the character of a varnish. If no linseed oil is employed in flatting, it is called a dead flat; but if a little is added, in order to produce a faint gloss, it is called a bastard flat. This part of the work forms one of the most unwholesome in which the painter is engaged, since the oil of turpentine, which is constantly evaporating during the process, is found to be extremely prejudicial to health.
As we are here speaking of a new house, we need not detail the process followed in repairing an old one. Nor is it necessary so to do even in respect of the processes themselves, for they are nearly the same for old work and new. The principal points of difference are these:—that in old work, greasy and dirty spots are washed with pearl-ash and water, or with turpentine; that the old paint is rubbed smooth with pumice-stone, or, if very rough, burned off; that a smaller number of new coats of paint will suffice; and that a larger proportion of turpentine is used than in new work.