Cyclopedia of Painting/Plain Oil Painting

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The processes of plain oil painting are in themselves extremely simple, and depend so much on manipulative skill that a description of them must be taken only as a general guide, not by any means sufficient in itself to make a good painter. This result is not arrived at by theoretical knowledge alone, however sound, but by long-continued and earnest practice.

On the other hand, it must be urged on the attention of painters the fact that practice alone will not accomplish the end desired; a painter who can only spread a quantity of paint over a given surface is little better than a machine, and it is hoped by the instruction given in the following pages, to awaken the interest of the painter, and to show him that his occupation is not merely manual, but that each branch of the trade, if properly understood, will afford scope for the exercise of mental acquirements and for the application of knowledge.

Before the painter can commence the absolute process of painting new work, it is necessary that he should clear it from any drops of glue or whitening which may have fallen on the surface, or which may have been accidentally left by the carpenter.

In this operation he uses the stopping knife. This knife is held so that a large portion of its edge may touch the surface, and it is slanted so as to be nearly horizontal, and thus the edge works as it were under the pieces of glue and putty and lifts rather than scrapes them off. Care must be taken that the knife is not held so that its surface would be perpendicular to the wood, and that only the smallest possible pressure is used, otherwise indentations might be made, and thus more harm than good would be done.

It must also be borne in mind that this process is not to be a universal scraping; it is merely remedial, to remove any excrescences which may exist, but its purpose is not to scrape or plane the wood. This is supposed to have been already done by the carpenter, and if it has not, a tool different from the stopping knife should be used.

The dusting brush, generally called the duster, must be freely used during this process so that all the particles scraped off may be removed. The largest of the brushes used for painting is sometimes employed as a duster previously to being devoted to its proper purpose, in order that it may be rendered softer; but this is not a good plan, for a certain amount of dust necessarily finds its way up the brush, and is liable to work out when it is being used for painting purposes, thus giving the work a coarse and gritty appearance and causing much annoyance.

The next stage of preparation is that called knotting, the purpose of which is to guard against the knots appearing in the finished work, by stopping their absorbent quality, or closing the apertures of the fibre, and thus preventing the effusion of gum or sap. It is, of course, strongly urged that wood should be thoroughly dry before it is used, but this is not within the power of the painter to control; he must take the wood as he finds it, and must do his best to counteract the effects of the new wood on his work.

It must be remembered that in the knots the ends of fibres, which are so many open tubes, are exposed, and thus, if all the sap or gum has exuded, they will present spots very much more absorbent than the surface of the board itself, whilst if the wood be new and the gum and sap flesh in it, these will from time to time exude and force off the paint, or cause it to become sticky.

Patent Knotting may be purchased at the color shops, and the following are two excellent recipes for making similar compositions, which are to be applied with a brush of the second size called a tool.

Add together a quarter of a pint of japanner's gold size, one teaspoonful of red lead, one pint of naphtha and seven ounces of orange shellac. This mixture is to be kept in a warm place whilst the shellac dissolves and must be frequently shaken.

White or red lead powder mixed with glue size and applied whilst warm.

Knotting is a composition of strong size, mixed with red lead for the first knotting, which prevents the gum coming through; the second knotting is a composition of white lead, red lead and oil, but in rooms where the knots happen to be very bad they are often silvered, which is done by laying on a coat of gold size and when properly dry a silver leaf is placed on them, which is sure to prevent the knots appearing.

When the knots are more than usually bad they must be cut out.

Priming. The first process of painting is called priming, which consists of laying on a coat of paint for the special purpose of diminishing the absorbent quality of the wood or plaster. The paint used for this purpose is generally a mixture of white lead and red lead, with a proper proportion of driers; but when the finishing color is to be black, dark green or dark brown the priming may be done with a lead color made of vegetable black and white lead in equal quantities.

These colors should be mixed with boiled oil for out-of-door, and with linseed oil for in-door work, a small quantity of turpentine being added in either case, the proportions being three parts of oil to one of turpentine. The paint should be rather thin so that it may be well adapted for rapid absorption by the new wood or plaster.

Some painters, in order to save the oil coats, have resorted to the objectionable practice of spreading a coat of size mixed with water and whiting over the new work.

This may serve for temporary purposes, but it will soon be seen that it should not be adopted in good work or where durability is expected. To a certain extent the size stops the absorbent powers of the wood or plaster, but it prevents the proper adhesion of the oil paint, which soon cracks or peels off. It may, however, be used with advantage in old work, where the grease would prevent the proper drying of the oil paint, but even in such cases it is best, when possible, to scrape the wood or plaster until a new surface is reached, on which the oil paint may be successfully applied.

When the priming is thoroughly dry, it is to be rubbed down with glass paper and this operation, although in itself simple, requires a certain amount of care so that the rubbing may be equally effective over the whole surface. In order that this result may be attained, the glass paper used should not be a mere scrap, rubbed carelessly about in various directions, by which means some parts will be passed over oftener than others, and the paint may be nearly rubbed off in one spot whilst it is left almost untouched on another. A piece of the paper should be wrapped round a flat piece of wood, say 4 inches long by 3 inches wide and 1 inch thick, forming a kind of brush, and this should be rubbed equally over the whole surface, which will thus be nicely smoothed, whilst its perfectly level character will not be injured. A piece of glass paper which has been used several times in this way should be saved for use in the later stages of the work, when great refinement is required. A strip of glass paper may be wrapped over the edge of a piece of wood shaped like a chisel for use in the edges of panels and similar situations, or round the finger or a piece of rag for the curved parts of mouldings, great care being taken that a stiff edge, such as is formed by a sudden bend in the glass paper, may not come in contact with the work, producing scratches which are very troublesome to get rid of. All the dust caused by the glass paper must be carefully removed by means of the duster. When the priming has been properly rubbed down the next operation is that of stopping.

Stopping consists in filling in and making good all nail-holes, bad joints and cracks with putty, or with a paste made of putty and white lead, called hard stopping; this is done with the stopping knife.

This is another of the operations which, although simple, require a certain amount of care, lest instead of contributing to, they may mar the success of the work. Thus let it be required to stop a crack in a panel; it will not be sufficient merely to press into the interstice a small quantity of stopping and then smooth it over, for as the stopping dries it contracts and sinks below the surface, and the crack becomes just as great an eye-sore as ever.

In such a case, the stopping should be forced as far down into the crack as possible; this may be done with the edge of the stopping knife, or with a thin piece of wood, leaving the stopping, however, slightly raised above the surface. In a day or two, before the second painting is proceeded with, the stopping will, owing to a certain amount of shrinking during drying, be found nearly level with the panel and may then be smoothed down with the stopping knife.

The circumstance calling for the greatest care in stopping, is where a panel or other part of the work has received a blow and a delve or shallow concavity is formed, for it will be clear that the mere skin of stopping required to level up such a spot, would be almost certain to crack off, leaving the place totally uncovered by paint. The best way to avoid such a result is to deepen the recess in parts by pricking holes in it with a bradawl and these should incline in different directions and should be more closely placed and more numerous near the edges than in the middle of the space. The point of the stopping-knife may he used for this purpose, and deep fissures will be formed thereby; into these fissures or holes the stopping is to be forced and the portion spread over the delve will thus be as it were nailed to the wood by the filaments penetrating into the holes.

This process should be slowly done, an interval being allowed to elapse between the first and second stopping, but this is supposing a condition which cannot always be fulfilled; the exigencies of business in these days of high pressure demanding that work shall be pushed on with the utmost rapidity; but it is desired to point out the means by which failure may be avoided, and the intelligent painter, knowing this, will be able in most cases to arrange his work in such a way that some portions may be proceeded with whilst the necessary delay is afforded to others, and thus, by economy of time, and proper organization of labor, the desired end may be accomplished.

The surface having been again touched off with the glass paper, the second painting is to be proceeded with. For the second coat, the same paint used for the priming, or white lead thinned with oil and a little turpentine and driers, may be employed, the proportion of driers for ordinary cases being 1+12 ounces to 10 pounds of white lead, but in winter, or in a damp climate, the proportion of driers must be increased. The following useful hints are here given:

It should be observed that second color for new work is made up chiefly with oil, as it best stops the suction of the wood, but second color for old work is made up chiefly with turpentine, because oil color would not dry or adhere to it so well.

The color should be spread on as evenly as possible, and to effect this as soon as the whole or a convenient quantity is covered, the brush should be passed over it in a direction contrary to that in which it is finally to be laid off; this is called crossing. After crossing it should be laid off softly and carefully in a direction contrary to the crossings, but with the grain of the wood, taking care that none of the cross brush marks be left visible. The criterion of good workmanship is, that the paint be laid evenly and the brush marks be not observed. In laying off, the brush should be laid into that portion of the work already done, that the joining may not be perceived. Every coat should be perfectly dry, and all dust carefully removed before the succeeding one is laid over it.

In the third painting some approach is made to the finishing color. Thus, if the finishing color is to be lavender, the third coat should consist of white, slightly tinted with that color. In some cases it is desirable that the coat preceding the finishing should be darker than that which is to be laid over it.

In the third painting, the oil and turpentine should be used in equal proportions.

The fourth may be considered as the finishing coat, although a fifth is often given, and always with great advantage. The finishing coat must not by any means be applied unless the third coat proves perfectly satisfactory; that is, unless the surface has dried absolutely uniform, as regards surface, for if one part is glossy and the other dull it will be clear that the absorbent quality is not stopped and the third painting must be repeated.

In commencing to repaint old work, the surface should, in the first case, be gone over with the stopping knife, removing all excrescences, and it is then to be rubbed with pumice stone and water, the greasy parts being well rubbed with turpentine.

Parts from which the paint has been entirely removed and decayed patches must then be gone over with a coat of priming color, and cracks and holes are to be made good with stopping. The first coat is then to be given and this is to be mixed with turpentine. The quality of the next coat will depend on the manner in which it is to be finished. If it is to be painted twice in oil and flatted, the next coat should be mixed up chiefly in oil, and tinted like the finishing color to form a ground for the flatting. The greater the gloss of the ground, the more dead will be the finishing coat, or flatting; likewise, the more dead the ground the better will the finishing oil shine. It is, therefore, a general rule, that for finishing in oil the undercoat should be turpentine, and for finishing flat the undercoat or ground color should be oil; but all turpentine grounds must have a little oil mixed with them, and all oil undercoats must have a small quantity of turpentine added to them, excepting the priming or first coat in new work.

In order to attain an absolutely solid appearance, some painters apply two coats of the finishing color, by which no doubt uniformity is secured, but the expense is, of course, materially increased thereby. There are, however, pigments of a cheaper but still permanent character, which approach in tone to the very best, and these may with advantage be used as a first finishing coat, over which the final color may be applied. Such colors must be carefully selected and must be well covered by the finishing coat.

Flatting, When the work is to be flatted, that is, when it is desired that the paint when dry should present a flat or dull appearance without any gloss, the paint used for the previous coat should be rather thicker than would under other circumstances be used; it should be mixed with linseed oil and turpentine and should be rather darker than the flatting itself is to be.

Special care is necessary in laying all the coats which precede the flatting; they must be very evenly spread and must be smoothed with glass paper in order that they may be perfectly level, otherwise the smallest irregularities will appear in the finished surface, to the injury of that perfectly flat appearance in which the beauty of the work consists.

The paint used in flatting consists of white lead with which, of course, the necessary coloring matter is mixed, turpentine alone being used as the medium with which the paint is thinned. The color should be rather lighter than is required, as it darkens a little whilst drying; a brushful should therefore be tried before the whole surface is painted in order to avoid subsequent disappointment. In order to assist in drying, japanners' gold size is sometimes used instead of driers.

Although it is, of course, necessary that the coat preceding the flatting should be dry, it ought not to be absolutely hard, for it is necessary that the flatting, which is mixed with turpentine only, should slightly dissolve the surface, so as to become in a degree incorporated with it, by which much beauty and solidity is obtained, whereas, if the previous coat had become quite hard the flatting would in most cases appear streaky when dry and would be liable to crack or peel off.

Owing to the special composition of the paint used in flatting, it dries very rapidly and two men should be engaged at once in flatting a wall. A plank placed across two step-ladders, or otherwise supported, is placed in front of the wall at about half the height from the ground. One of the painters stands on this whilst the other stands on the ground. The last mentioned commences the work, painting a strip about 18 inches wide and carrying it up as high as he can conveniently reach, he works rapidly, crossing occasionally, so that no brush marks in any one direction may be visible, laying off very lightly; that is, continuing the action of his brush, withdrawing it gradually so that the points of the hairs may only skim lightly over the work.

The painter above proceeds with the operation from the line where his fellow painter left it, and carries it up to the top of the wall, the first painter meanwhile getting on with another strip, both painters being exceedingly careful that no break shall occur and that the lines at which their work join shall not be visible in the slightest degree.

Brushes called stipplers are much used; these are broad and flat, and in form resemble a hairbrush. In practice the stipplers are gently dabbed against the wet paint, producing a level grain over the whole surface, something like the tooth on the drawing paper called not hotpressed. These brushes may be obtained of various shapes, the handles of some being continuous with the back, whilst in others it is fixed above, like that of a black-lead brush. The adoption of either form is, of course, a matter of taste.

In flatting a door, the panels must be finished first, great care being taken to carry the paint clean into the edges and corners. The stiles or framing should then be done. It is convenient to paint the muntins, or munnions, first; these are the upright pieces in the middle of the door. Next to these come the upper, middle and lower rails, the horizontals which cross the door, and lastly the upright stiles, or external vertical portions of the frame of the door. The brush marks, should any appear at the parts where the work is necessarily in cross directions, will correspond with the joints which would in reality exist at these parts.

Painting Plaster. The first coat is composed of white lead mixed with linseed oil and a small quantity of litharge, the paint being rather thinner than would be used for general purposes, in order that it may soak well into the absorbent surface of the plaster. The next coat should also be thin so that the plaster may be thoroughly saturated. This will be only partially absorbed, and it will be necessary to make the third coat much thicker, mixing with it turpentine, and some of the coloring matter approaching the future tint of the room. The fourth coat should be thicker still and should be mixed with equal parts of oil and turpentine, together with the dry ingredient, sugar of lead, instead of litharge. The color should be much darker than that which is to constitute the finishing coat. All these coats must be laid on with the greatest attention as to smoothing, and they should each be thoroughly dry before the succeeding coat is applied, and should be well rubbed down with glass paper. The last coat which is to precede the flatting, however, should not be quite hardened before the finishing is applied for reasons previously explained. The process of flatting has already been described.

Painting New Walls or Stucco. It does not appear that any painting in oil can be done to any good or serviceable effect in stucco, unless not merely the surface is dry, but the walls have been erected a sufficient time to permit the mass of brickwork to have acquired a sufficient degree of dryness.

When stucco is on battened work, it may be painted over much sooner than when prepared as brick. Indeed, the greater part of the mystery of painting stucco so as to stand or wear well, certainly consists in attending to these observations, for whoever has observed the expansive power of water, not only in congelation, but also in evaporation, must be well aware that when it meets with any foreign body obstructing its escape, as oil paint, for instance, it immediately resists it, forming a number of vesicles or particles, containing an acrid lime water which forces off the layers of plaster, and frequently causes large defective patches extremely difficult to get the better of.

Perhaps in general cases, where persons are building on their own property, or for themselves, two or three years are not too long to suffer the stucco to remain unpainted; though frequently in speculative works as many weeks are scarcely allowed. Indeed, there are some nostrums set forth in favor of which it is stated, in spite of all the natural properties of bodies, that stucco may, after having been washed over with these liquids, be painted immediately with oil colors. It is true there may be instances, and in many experiments some will be found, that appear to counteract the general laws of nature, but on following them up to their causes it will be found otherwise.

Supposing the foregoing precautions to have been attended to, there can be no better mode adopted for priming or laying on the first coat on stucco than by linseed or nut oil boiled with driers, with a proper brush, taking care in all cases not to lay on too much so as to render the surface rough and irregular, and not more than the stucco will absorb. It should then be covered with three or four coats of ceruse or white lead, prepared as described for painting on wainscoting, letting each coat have sufficient time to dry hard.

If time will permit, two or three days between each coat will not be too long. If the stucco is intended to be finished of any given tint, as gray, light green or apricot, it will then be proper, about the third coat of painting, to prepare the ground for such tint by a slight advance towards it.