Part 2
Ultramarine was originally made by grinding the valuable mineral _Lapis lazuli_. Genuine ultramarine so made is very expensive, but artificial French and German ultramarines are made of better color, and cheaply, by fusing and washing and reheating a mixture of soda, silica, alum, and sulphur. This blue is chiefly used for coloring wall papers.
Cobalt blue is an oxide of cobalt made by roasting cobalt ore. It makes a beautiful color, and works well in water or oil.
Smalt, Saxon blue and Royal blue are colored by oxides of cobalt.
There are a few other blues, such as Celestial or Brunswick blue, damp blue and verditer, that are chemical compounds, compounds of alum, copper, lime, and other substances; but they are so seldom used in this country that it is unnecessary to describe them in detail.
=Yellows.=--Chrome yellows are chromates of lead, produced by mixing dilute solutions of acetate or nitrate of lead and bichromate of potash. This makes a medium tint known as “middle chrome.” The addition of sulphate of lead makes this paler, when it is known as “lemon chrome,” whereas the addition of caustic lime makes it “orange chrome” of a darker color. The chromes mix well with oil and with white lead either in oil or water. They stand the sun well, but like other lead salts, become dark in bad air. Chrome yellow is frequently adulterated with gypsum.
Naples yellow is a salt of lead and antimony, supposed to have been originally made from a natural volcanic product at Naples. It is not so brilliant as chrome, but has the same characteristics. King’s yellow is made from arsenic, and is therefore a dangerous color to handle, or use for internal work. It is not durable, and it injures several other colors when mixed with them. Chinese yellow, arsenic yellow, and yellow orpiment are other names for this yellow.
Yellow ochre is a natural clay colored by oxide of iron, and found abundantly in many parts of the world. It is not very brilliant, but is well suited for distemper work, as it is not affected by light or air. It does not lose its color when mixed with lime washes as many other colors do. There are several varieties of ochres, all having the same characteristics differing only in color which varies from a golden to a dark brown.
=Terra De Sienna=, or raw Sienna, is a clay, stained with oxides of iron and manganese, and of a dull yellow color. It is durable both in oil and water, and is useful in all work, especially in graining.
=Browns.=--Browns generally owe their color to oxide of iron. Raw umber is a clay similar to ochre colored by oxide of iron. The best comes from Turkey; it is very durable both in water and in oil; does not injure other colors when mixed with them.
=Burnt Umber= is the last mentioned material burnt to give it a darker color. It is useful as a drier, and in mixing with white lead to make a stone color.
=Vandyke Brown.=--This color is an earthy dark brown mineral; it is durable both in oil and water, and is frequently employed in graining.
=Purple Brown= is of a reddish-brown color. It should be used with boiled oil--and a little varnish and driers for outside work.
=Burnt Sienna= is produced by burning raw sienna. It is the best color for shading gold.
=Brown Pink= is a vegetable color often of a greenish hue. It works well in water and oil, but dries badly, and will not keep its color when mixed with white lead. Spanish brown and brown ochre are clays colored naturally by various oxides.
=Reds.=--Carmine, made from the cochineal insect, is the most brilliant red color known. It is, however, too expensive for ordinary house painting, and is not durable. It is sometimes used for inside decoration.
=Red Lead.=--This color has already been described on page 11.
=Vermilion.=--This is a sulphide of mercury in a natural state as cinnabar. The best comes from China. Artificial vermilion is also made both in China and in this country from a mixture of sulphur and mercury. Genuine vermilion is very durable, but when mixed with red lead, as it is sometimes, it will not stand the weather. It can be tested by heating in a test tube; if genuine it will entirely volatilize. German vermilion is the tersulphide of antimony, and is of an orange-red color.
=Indian Red.=--This color is a ground hematite ore brought from Bengal; it is sometimes made artificially by calcining sulphate of iron. The tints vary, but a rosy hue is considered the best. It may be used with turpentine and a little varnish to produce a dull surface, drying rapidly, or with boiled oil and a little driers, in which case a glossy surface will be produced, drying more slowly.
=Chinese Red= and Persian red are chromates of lead, produced by boiling white lead with a solution of bichromate of potash. The tint of Persian red is obtained by the employment of sulphuric acid.
=Venetian Red= is obtained by heating sulphate of iron produced as a waste product at tin and copper works. It is often adulterated by mixing sulphate of lime with it during the manufacture. When pure, it is often called “bright red.” Special tints of purple and brown are frequently required, which greatly enhance the value of the material. These tints should be obtained in the process of manufacture, and not produced by mixing together a variety of different shades of color. When the tint desired is attempted to be obtained by this latter course it is never so good, and the materials produced are known in the trade as ‘faced colors,’ and are of inferior value.
=Rose Pink.=--This is made of a sort of chalk or whiting stained with a tincture of Brazil wood. It fades very quickly, but it is used for paperhangings, common distemper, and for staining cheap furniture.
=Lakes.=--These are made by precipitating colored vegetable tinctures by means of alum and carbonate of potash. The alumina combines with the organic coloring matter and separates it from the solution. The tincture used varies in the different descriptions of lake. The best, made from cochineal or madder, is used for internal work. Drop lake is made by dropping a mixture of Brazil wood through a funnel on to a slab. The drops are dried and mixed into a paste with gum water. It is sometimes called “Brazil wood lake.” Scarlet lake is made from cochineal; so also are Florentine lake, Hamburg lake, Chinese lake, Roman lake, Venetian lake and Carminated lake.
=Orange.=--Chrome orange is a chromate of lead, brighter than vermillion, but less durable. Orange ochre is a bright yellow ochre burnt to give it warmth of tint; it dries and works well in water or oil, and is very durable. It is known also as Spanish ochre. Orange red is produced by a further oxidation than is required for red lead. It is a brighter and better color.
=Greens.=--These, of course, may be made by mixing blue and yellow together, but such mixtures are less durable than those produced direct from copper, arsenic, etc. The latter are, however, objectionable for use in distemper or on wall papers, as they are very injurious to health. Brunswick green of the best kind is made by treating copper with sal-ammoniac. Chalk, lead and alum are sometimes added. It has rather a bluish tinge; dries well in oil, is durable, and not poisonous. Common Brunswick green is made by mixing chromate of lead and Prussian blue with sulphate of baryta. It is not as durable as real Brunswick green. Mineral green is made from bi-basic carbonate of copper; it weathers well. Verdigris is acetate of copper. It furnishes a bluish-green color, durable in oil or varnish, but not in water; it dries rapidly, but requires great care in using owing to its poisonous qualities. Green verditer is a carbonate of copper and lime; is not very durable. Prussian green is made by mixing different substances with Prussian blue. There are a number of other greens made from copper, but they all possess in a greater or lesser degree, the same qualities as the foregoing. Emerald or Paris green is made of verdigris mixed with a solution of arsenious acid. It is of a very brilliant color, but is very poisonous; is difficult to grind, and dries badly in oil. It should be purchased ready ground in oil, as in that case the poisonous particles do not fly about, and the difficulty of grinding is avoided. Scheele’s green and Vienna green are also arseniates of copper, and highly poisonous. Chrome green should be made from the oxide of chromium, and is very durable. An inferior chrome green is made, however, by mixing chromate of lead and Prussian blue, as above mentioned, and is called Brunswick green. The chrome should be free from acid or the color will fade; it may be tested by placing it for several days in strong sunlight.
=Proportions of Ingredients in Mixed Paint.=--The composition of paints should be governed by the nature of the material to be painted. Thus the paints respectively best adapted for painting wood and iron differ considerably. The kind of surface to be covered, _i. e._, a porous surface requires more oil than one that is impervious. The nature and appearance of the work to be done. Delicate tints require colorless oil; a flatted surface must be painted without oil, which gives gloss to a shining surface. Again, paint used for surfaces intended to be varnished must contain a minimum of oil. The climate and the degree of exposure to which the work will be subjected; thus, for outside work boiled oil is used, because it weathers better than raw oil. Turps is avoided as much as possible, because it evaporates and does not last; if, however, the work is to be exposed to the sun, turps are necessary to prevent the paint from blistering. The skill of the painter also affects the composition; a good workman can lay on even coats with a smaller quantity of oil and turps than a man who is unskilful; extra turps, especially, are often added to save labor. The quality of the materials makes an important difference in the proportions used. Thus more oil and turps will combine with pure than with impure white lead; thick oil must be used in greater quantity than thin oil. When paint is purchased ready ground in oil, a soft paste will require less turps and oil for thinning than a thick paste. Lastly, the different coats of paint vary in their composition; the first coat laid on to new work requires a good deal of oil to soak into the material; on old work the first coat requires turpentine to make it adhere; the intermediate coats contain a proportion of turpentine to make them work smoothly, and to the final coats the coloring materials are added, the remainder of the ingredients being varied as already described, according as the surface is to be glossy or flatted.
The exact proportion of the ingredients best to be used in mixing paints varies according to their quality, the nature of the work required, the climate, and other considerations. The composition of the paint for the different coats also varies considerably. The proportions given in the following table, must, therefore, only be taken as an approximate guide when the materials are of good quality.
_Table showing the composition of the different coats of white paint, and the quantities required to cover 100 yards of newly worked pine._
+-------+--------+---------+---------+--------+---------+ | RED | WHITE | RAW | BOILED | TURPE- | DRIERS. | | LEAD. | LEAD. | LINSEED | LINSEED | NTINE. | | | | | OIL. | OIL. | | | --------------+-------+--------+---------+---------+--------+---------+ | | | | | | | _Inside work, | | | | | | | 4 coats | lbs. | lbs. | pts. | | | lbs. | not flatted._ | | | | | | | | | | | | | | Priming** | ¹⁄₂ | 16 | 6 | -- | -- | ¹⁄₄ | | | | | | | | 2d Coat | * | 15 | 3¹⁄₂ | -- | 1¹⁄₂ | ¹⁄₄ | | | | | | | | 3d Coat | -- | 13 | 2¹⁄₂ | -- | 1¹⁄₂ | ¹⁄₄ | | | | | | | | 4th Coat | -- | 13 | 2¹⁄₂ | -- | 1¹⁄₂ | ¹⁄₄ | | | | | | | | _Inside work, | | | | | | | 4 coats and | | | | | | | flatting._ | | | | | | | | | | | | | | Priming | 1¹⁄₂ | 16 | 6 | -- | ¹⁄₂ | 1-8 | | | | | | | | 2d Coat | -- | 12 | 4 | -- | 1¹⁄₂ | 1-10 | | | | | | | | 3d Coat | -- | 12 | 4 | -- | 0 | 1-10 | | | | | | | | 4th Coat | -- | 12 | 4 | -- | 0 | 1-10 | | | | | | | | Flatting | -- | 9 | 0 | -- | 3¹⁄₂ | 1-10 | | | | | | | | _Outside work,| | | | | | | 4 coats | | | | | | | not flatted._ | | | | | | | | | | | | | | Priming*** | 2 | 18¹⁄₂ | 2 | 2 | -- | 1-8 | | | | | | | | 2d Coat | -- | 15 | 2 | 2 | ¹⁄₂ | 1-10 | | | | | | | | 3d Coat | -- | 15 | 2 | 2 | ¹⁄₂ | 1-10 | | | | | | | | 4th Coat | -- | 15 | 3 | 2¹⁄₂ | 0 | 1-10 | | | | | | | | --------------+-------+--------+---------+---------+--------+---------+
* Sometimes just enough red lead is used to give a flesh-colored tint.
** Sometimes more red lead is used and less drier.
*** When the finished color is not to be pure white, it is better to have nearly all the oil boiled oil. All boiled oil does not work well. For pure white a larger proportion of raw oil is necessary, because boiled oil is too dark.
For every 100 square yards, besides the materials enumerated in the foregoing, 2¹⁄₂ lbs. of white lead and 5 lbs. of putty will be required for stopping.
The area which a given quantity of paint will cover depends upon the nature of the surface to which it is applied, the proportion of the ingredients and the state of the weather. When the work is required to dry quickly, more turpentine is added to all the coats.
In repainting old work, two coats are generally required, the old painting being considered as priming. Sometimes another coat may be deemed necessary.
For outside old work exposed to the sun, both coats should contain one pint of turpentine and four pints of boiled oil, the remaining ingredients being as stated in the foregoing table. The extra turpentine is used to prevent blistering.
In cold weather more turpentine should be used to make the paint flow freely.
=Operations.=--All priming should be rubbed out as far as possible, for if it is flowed out loosely or laid on thick it will be apt to blister and run. In priming over spots, however, where _patching_ is being done, it may sometimes be necessary to leave the coat thick or heavy, for new work can never be re-touched and look well, after the work is second coated or finished; for such re-touching would show and spoil the whole work. In priming the paint should flow easily, and the brush should be pressed on to the wood so that the paint will be forced into the pores. In all cases it is a great saving of time to cover as large a surface as convenient before smoothing or finishing off. All work on the same surface should be finished at the one application, if possible, for “laps”--which form the junctions of work done at different times--should be avoided wherever they can, as they are sure to disfigure the work where they exist. Of course, it is sometimes impossible to avoid laps, but where they must occur, care should be taken to make the connection with as little “lap” as possible or it will be certain to show through the work when finished. The defect, if occurring during the second coating, will show much worse than in the priming coat.
In painting, like everything else, a system must be followed to make much headway. Experience, perhaps, is the only effective teacher in this matter; and any rules laid down by us will have but little effect, if the operator does not, or can not systematize. The workman who follows a system will do nearly twice as much work with less labor, than the man who works only by the rule of thumb. In painting blinds, lattices, railings, cut brackets or other similar work, some method of operation should be adopted. A little observation on the part of the operator, will soon teach him the best methods to adopt in doing any particular kind of work.
=Preparing the Work.=--In preparing work for painting, too much care cannot be exercised, as succeeding coats and the final result depend very much on the proper condition of the work when the priming coat is applied. First, all the rough places in the wood should be rubbed down with a block covered with sandpaper; and the mouldings and beads should be well cleaned out with sandpaper. Then (and this is a matter of prime importance) every knot, however small, every indication of sap on the wood, or discoloration of any kind, and every appearance of pitch or gum, should be carefully varnished over with white shellac varnish, if the work is to be finished in white or light tints--or with varnish made from unbleached or common shellac, if the work is to be finished in dark shades. The common shellac, in the latter case, answers equally well with the bleached article, and at less cost. This should not, under any circumstances, be neglected, as it is impossible, in the nature of things, otherwise to make good work.
When work is to be finished with two coats, the putty used for stopping the nail-heads and other indentations should be made of white lead, worked up with common whiting to the proper consistency, and the filling should be done after the first coat shall have become well dried. When more than two coats are to be applied, the filling should be done between the first and second coats, with ordinary pure linseed-oil putty.
It should be adopted as a rule, never to apply pure white as a priming coat; no matter whether the work is to be finished with one or four coats, the result will always be more satisfactory if the first coat be stained. A little finely-ground lampblack answers as well for this as anything.
The only way to produce solid, uniform work, is by making every succeeding coat lighter in tint than the one which preceded it. This is especially the case with walls, and other extended flat surfaces. No matter what the finish is to be, the first coat should always be darker than the one which succeeds it; and the darker the shade of the finishing coat, the more important it is that this rule should be observed. If the work is to be finished with black, prime with black. If with green, let that be the color of all the preceding coats. If with blue, let that color be the ground work. What can be more stupid than applying to work which is to be finished in imitation of black walnut a priming coat of white? All work should be primed especially with regard to the finishing color.
There is not half enough of dark colors used in priming applications. Venetian red, finely ground in boiled oil, deeply stained with black--and used very thin, in order to stain the wood as much as possible--is the best first coat for work which is to be finished in imitation of black walnut or other dark wood. The succeeding coats should be as dark as may be with a view to the proper shade of ground-work for the graining. In such case, if (as must happen in the ordinary course of events) the work becomes bruised or “chipped”--by an accidental knock from a chair leg or other article of house furniture--the general appearance of it is little impaired thereby. Quite the contrary, however, is the case if the underneath coats are white. Then, an accident of the kind before mentioned, shows a white spot, which staringly proclaims the work to be a delusion and a sham. Dark colors, too, as the Venetian red before mentioned, make better foundations than white lead or zinc. They dry harder and “rub” better, and, what is most important, cost less.
This matter having been duly considered, let us now proceed to the coats succeeding the first. Before applying a second coat, the first should be carefully rubbed, and all the nail-heads and other indentations carefully stopped with pure linseed-oil putty--using for flat surfaces a square-bladed putty-knife. Puttying with the fingers should never be tolerated (good work is now the subject under consideration). This done, the whole should be carefully examined to ascertain if the oil in the former coat shall have revealed any resinous or pitchy spots, not previously covered with the shellac. These preliminaries being attended to, the work may be considered ready for a second coat. The directions as to rubbing with sandpaper are to be observed in all the succeeding coats. As a rule, on interior work, paint should never be applied to a surface which has not been previously rubbed.
Sandpaper for fresh work and pumice-stone for old work. Always distrust the education of a painter in his trade who goes to work without a lump of pumice-stone, a sheet of sandpaper, a putty-knife, and a rag to wipe off the spatters--sparks, as the Irish not inaptly call them. Apropos of spatters! Every painter has seen (the result too of unpardonable negligence) plates of glass so covered with spatters, that to remove them would require more time than would serve to paint the woodwork of a “full-trimmed” window.
In priming work which is to be finished in oak, finely-ground French ochre is recommended. The objection to this pigment, that it does not work smoothly and easily under the brush, has arisen from its coarseness. Finely ground in boiled oil, it works as smoothly as white lead, and makes an excellent foundation for the succeeding coats.
For walls the first coat should be as dark in shade and as thin as practicable, the object being to stain the plaster as much as possible. Indeed, if the whole mass of plaster could be stained through and through, it would be desirable to so stain it.
The use of glue in wall painting is of doubtful propriety. It should never, under any circumstance, be put on until after the second coat, and then rubbed on with a rag, very lightly. In first-class work, however, its use is not recommended.
Plaster mixed with weak glue-size--which prevents its setting too rapidly--is the best material for stopping walls preparatory to painting, and each coat of paint should be carefully rubbed with worn sand-paper, before the succeeding coat is put on. For preparing walls a small pocket-trowel will be found a most serviceable tool, or a trowel-shaped putty-knife, which article has come into general use.