The author trusts that he has made it clear to the reader that the subject of paint and colour mixing is far more comprehensive than might at first sight appear. Yet it is of such great importance that every house painter worthy of the name should make himself acquainted with it, and, unless he be colour blind, he can do so without difficulty if he will only take the trouble to make a number of tests and experiments.
In “putting on,â€i.e., engaging the services of journeyman, the master painter will find, as a rule, that only about one in twenty has any knowledge of colour mixing, yet these men could, if they would only do so, easily make themselves at least fairly proficient in the subject by devoting their spare time to making various mixtures and using a box of ordinary artists’ oil colours for the purpose. A very good box can be purchased for about ten shillings.
Having given some practical tests for colours, we may now add one or two for turpentine.
—It is of considerable importance that turpentine used for painting should be quite pure. To test the purity in a practical way pour a few drops on a sheet of white writing paper; if it is pure the mark will evaporate in a few minutes, leaving the paper quite clean. If, however, paraffin oil has been added to the turpentine it will leave a greasy mark on the paper, which will not disappear for several hours or even days. Turpentine is sometimes adulterated with benzine. The test above will not detect this, as the benzine will not leave a greasy mark. The evaporation, however, will be more rapid than when the turpentine is pure. When turpentine is very old, it becomes “gummy†orthick, and is unsuitable for mixing with paint. This condition is indicated by a greasy mark left on writing paper when a few drops are poured upon it.
Another very simple test for the purity of turpentine is to place a sample in a small white bottle and shake vigorously, carefully observing the time that it takes the bubbles that arise from the agitation to disappear. If the turpentine is adulterated with paraffin oil the bubbles will hold longer than when it is pure. The best plan is to have a bottle containing pure turpentine and another containing the suspected sample, and to shake up both together, comparing the rapidity with which the bubbles disappear.
Paraffin oil is also sometimes detected by smell: pour a couple of drops on the palm of the hand, rub the two hands briskly together, when the characteristic smell of paraffin will be easily detected if any considerable amount be present. Turpentine is sometimes adulterated with rosin spirit, and this can only be detected by means of analysis.
—To ascertain with absolute certainty whether a sample of linseed oil is pure or not is by no means easy, and can only be done by aid of chemistry. There are various methods by which the adulteration can be ascertained, but we hesitate to print them here, because they may prove misleading to the uninitiated. The experienced painter has two tests of his own, viz., smell and the working of the oil, and if these lead him to suppose it is adulterated his only safe plan is to obtain the services of a competent chemist.
We next reach a consideration of the different qualities of the principal pigments, and can best show these by means of tables.
Pigments Liable to Change under the Influence of Sulphuretted Hydrogen, Air, and Moisture:Yellow.—Turner’s yellow, chrome yellow, mineral yellow, Naples yellow.White.—Cremintz white, flake white, pearl white.Red.—Red lead, purple red, iodine scarlet.Green.—Verdigris, Scheele’s green, emerald green, mountain green.Blue.—Prussian blue, Antwerp blue.Orange.—Orange chrome.Pigments Little Liable to Change under the Influence of Sulphuretted Hydrogen, Air and Mixture:White.—Zinc white, constant white, tin white.Red.—Vermilion, red ochre, Indian red, madder lakes.Yellow.—Yellow ochre, barium chromate, zinc chromate, aureolin, raw sienna.Green.—Chrome green, cobalt green.Blue.—Ultramarine, smalt, Thenard’s blue.Brown.—Vandyke brown, raw umber, burnt umber, manganese brown, sepia.Black.—Ivory black, lamp black, Indian ink, graphite.Orange.—Orange vermilion, burnt sienna.Pigment Liable to Deterioration when in Contact with White Lead, Chrome or other Lead Pigment:Yellow.—Yellow orpiment, king’s yellow, Indian yellow, gamboge.Red.—Iodine scarlet, cochineal, carmine.Orange.—Golden antimony sulphide, orange orpiment.Green.—Sap green.Blue.—Ultramarine.Pigments which are Little Affected by Heat, and which may be Employed when the Material has to Stand Fire:White.—Tin white, barium white, zinc white.Red.—Red ochre, Venetian red, Indian red.Yellow.—Naples yellow, antimony yellow.Blue.—Smalt and royal blue, ultramarine.Green.—Chrome green, cobalt green.Orange.—Burnt sienna, burnt ochre.Brown.—Burnt umber, manganese brown.Black.—Graphite, mineral black.Colours that may be Used with Lime:White.—Permanent white,i.e., baryta white, gypsum, zinc white.Red.—The vermilions, light red, Venetian red, Indian red, madder lakes.Orange.—Cadmium, orange chrome, Mars orange, burnt sienna, burnt Roman ochre, light red.Yellow.—Aureolin, cadmium yellow, lemon yellow, Naples yellow, Mars yellow, raw sienna, yellow ochre, Roman ochre, transparent gold ochre, brown ochre, Indian yellow, Oxford ochre.Green.—Oxide of chromium, transparent oxide of chromium, viridian, emerald green, malachite green, verdigris, terre verte, cobalt green, chrome green.Blue.—Genuine ultramarine, artificial ultramarine, new blue, permanent blue, cobalt blue, cerulean blue, smalt.Purple.—Purple madder, Mars violet.Brown.—Bone brown, bistre, Prussian brown, burnt umber, Vienna brown, Vandyke brown, Cologne earth, asphaltum, Cassel earth, manganese brown.Citrine.—Raw umber, Mars brown.Blacks.—Ivory black, lamp black, blue black, charcoal black, Cork black, Indian ink, black lead, drop black, plumbago.
Pigments Liable to Change under the Influence of Sulphuretted Hydrogen, Air, and Moisture:
Yellow.—Turner’s yellow, chrome yellow, mineral yellow, Naples yellow.
White.—Cremintz white, flake white, pearl white.
Red.—Red lead, purple red, iodine scarlet.
Green.—Verdigris, Scheele’s green, emerald green, mountain green.
Blue.—Prussian blue, Antwerp blue.
Orange.—Orange chrome.
Pigments Little Liable to Change under the Influence of Sulphuretted Hydrogen, Air and Mixture:
White.—Zinc white, constant white, tin white.
Red.—Vermilion, red ochre, Indian red, madder lakes.
Yellow.—Yellow ochre, barium chromate, zinc chromate, aureolin, raw sienna.
Green.—Chrome green, cobalt green.
Blue.—Ultramarine, smalt, Thenard’s blue.
Brown.—Vandyke brown, raw umber, burnt umber, manganese brown, sepia.
Black.—Ivory black, lamp black, Indian ink, graphite.
Orange.—Orange vermilion, burnt sienna.
Pigment Liable to Deterioration when in Contact with White Lead, Chrome or other Lead Pigment:
Yellow.—Yellow orpiment, king’s yellow, Indian yellow, gamboge.
Red.—Iodine scarlet, cochineal, carmine.
Orange.—Golden antimony sulphide, orange orpiment.
Green.—Sap green.
Blue.—Ultramarine.
Pigments which are Little Affected by Heat, and which may be Employed when the Material has to Stand Fire:
White.—Tin white, barium white, zinc white.
Red.—Red ochre, Venetian red, Indian red.
Yellow.—Naples yellow, antimony yellow.
Blue.—Smalt and royal blue, ultramarine.
Green.—Chrome green, cobalt green.
Orange.—Burnt sienna, burnt ochre.
Brown.—Burnt umber, manganese brown.
Black.—Graphite, mineral black.
Colours that may be Used with Lime:
White.—Permanent white,i.e., baryta white, gypsum, zinc white.
Red.—The vermilions, light red, Venetian red, Indian red, madder lakes.
Orange.—Cadmium, orange chrome, Mars orange, burnt sienna, burnt Roman ochre, light red.
Yellow.—Aureolin, cadmium yellow, lemon yellow, Naples yellow, Mars yellow, raw sienna, yellow ochre, Roman ochre, transparent gold ochre, brown ochre, Indian yellow, Oxford ochre.
Green.—Oxide of chromium, transparent oxide of chromium, viridian, emerald green, malachite green, verdigris, terre verte, cobalt green, chrome green.
Blue.—Genuine ultramarine, artificial ultramarine, new blue, permanent blue, cobalt blue, cerulean blue, smalt.
Purple.—Purple madder, Mars violet.
Brown.—Bone brown, bistre, Prussian brown, burnt umber, Vienna brown, Vandyke brown, Cologne earth, asphaltum, Cassel earth, manganese brown.
Citrine.—Raw umber, Mars brown.
Blacks.—Ivory black, lamp black, blue black, charcoal black, Cork black, Indian ink, black lead, drop black, plumbago.
We think it well to include here some information concerning brushes, but may first give a brief description of the way in which they are made, taking the firm of G. B. Kent & Sons, Ltd., as an example, as the author had the pleasure of going over their factory some time since. The following is his account written for “The Decorators’ Magazineâ€:—
A superficial observer may be inclined to think there is no particular advantage to the painter and decorator in possessing a knowledge as to how the tools he uses are made. Yet such a knowledge may help him considerably in judging as to the quality of those tools, and it will be at once acknowledged that an ability to discriminate in this respect is of considerable value. For brushes varygreatly in quality, far more so, perhaps, than our readers may imagine possible. Everyone knows that there are good brushes that cost more than a trifle, and rubbishy goods, chiefly of foreign make, that can be bought for, perhaps, half the amount. Probably there is not a reader who does not fully understand that it is far better in the end to buy the best quality brushes, that is, that it is cheaper to pay a higher price, because the work with such brushes can be done quicker and better than it can by the inferior ones, and also because the superior quality lasts much longer. Those things are well understood among most painters, and even if some of themwilluse cheap stainers and lose money in consequence, they have, at least, learned the lesson of the necessity of using only best quality tools.
But it is not a comparison between high grade and low grade brushes that we now want to make, it is rather to direct attention to the difference that exists in the actual quality of so-called first-class tools of different makes. It is this difference than can best be understood after inspecting the process of brush making, and it must be acknowledged that adulteration can be carried on in the manufacture of brushes to a considerable extent. Take a common ground brush as an example. The actual brush part should consist wholly of hog’s bristles, for there is nothing yet discovered that gives better results. Yet there are on the market many brushes marked “pure bristle†which really contain more or less a large proportion of horsehair or other material which makes a poor substitute, but which cannot be easily detected, in fact, it is the difficulty of detection which has probably given rise to the objectionable adulteration referred to.
The objection to horsehair in a painter’s brush is that it is flabby and without spring, but its presence in adulterating brushes can be understood when it is said that approximately the price of horsehair is 1s. 9d. to 2s. 2d., and bristles 8s. to 9s. per pound. It certainly requires an expert to state positively whether horsehair is included or not, but there are certain signs that, with care, will determine the matter, at least to a certain extent. The real bristle has its end split—called a “flag†end—the root end is considerably larger and cannot be mistaken. The spring or elasticity is anotherindication of the bristle. The horsehair, on the other hand, is the same size both ends, and has no flag end; if the suspected bristles be viewed under a strong reading glass the difference can be told without a great deal of difficulty.
At the works of Messrs. G. B. Kent & Sons, Ltd., the author was shown how suspected brushes sent out had been dissected and the various parts divided up, and it was surprising to see how much horsehair could be included in a brush without giving it any out-of-the-way appearance. There were little piles of horsehair of different lengths, while the bristles were all sorted into other piles, each of different lengths. Photographs of the brushes that have been dissected in this way have been distributed through the trade, and they have no doubt proved of use in showing painters that adulteration in brushes is carried on to almost as great an extent as it is in paint materials. No adulteration whatever in painting brushes is permitted in the factory of G. B. Kent & Sons.
Certainly the brush department in any brush manufactory, which is of the most importance is the bristle room, and it was to this that the author was first taken. There were bristles of many different kinds, most of them tied up into neat bundles ready to be afterwards dealt with. For instance, Siberian Okatka, and perhaps most important to my readers because they make the best paint brushes, having an excellent spring and being stiff. They are very costly and are rarely used by themselves, nor is it necessary, because other varieties of bristles may be mixed in, and it is this mixing or blending that constitutes so important a part in the brush manufacturer’s art. Indeed, the purchase and blending takes years of careful study to learn. One class of bristle is introduced into the mixing to give strength, another straightness, another solidity, another colour, and it is the judicious blending, the knowledge of which is acquired only by much experience, which makes a first-class brush for first-class work, and having the requisite spring and durability and the band of which will not burst.
The process of dividing the bristles into uniform lengths is termed “dragging,†a very interesting process which requires considerable expertness on the part of the operator. A handful of bristles, after being mixed, is placed against a gauge, and theoperator, grasping firmly those bristles which project beyond a mark which indicates the required length, withdraws them with his thumb and finger and places them aside. The whole bundle having been gone over in this way, a second dragging to the next mark is made, and so on until the bristles are arranged in little piles of uniform lengths.
The operation of “mixing†is also interesting. This is done in order to obtain an uniform colour and quality in the bristles. First, all the bristles of different colours are piled on the top of one another, varying considerably in colour in the different layers from top to bottom. Perhaps there will be one layer nearly white and another nearly black. If these were all mixed up indiscriminately to make a brush, the result would be a very patchy appearance that would not be liked. The object, therefore, is to have an equal admixture of black and white throughout. A workman takes in his hand a portion of the bristles from top to bottom, cutting through all at once. These he holds in his two hands and ‘jabs’—for the want of a better word—through a steel comb which is fixed upright before him. This mixes the different coloured bristles, and at the same time pulls out inferior or woolly parts that may have been left in. As each handful of bristles is dressed in this way it is laid aside, and when the whole is completed the second dressing is gone through in the same way as the first, the result being that the admixture is perfect, and the appearance of any one part of the pile is exactly the same as that of the other. It is essential also that all the bristles should lie the same way, and, as in the rough an uncertain small proportion of the bristles arrive with their heads the wrong way, to extract them another small comb, termed an ‘engine,’ with teeth very close together, is used; the ‘flag’ end of the handful is combed over this, and the roots of the ‘turned’ hairs catch in the comb.
OLD ROSEMOSS GREYIVY GREENWARM GREYGREEN SLATELEADSEA FOAMSILVER GREYAPPLE GREENSTONESLATEMIDDLE STONEGRANITEDARK OAKASH GREYIVORY
It will be unnecessary to describe in detail how every brush is made, but an ordinary ground brush will serve as an example. The actual manufacture is not difficult. First the bristles are carefully weighed out so that every brush of the same grade has exactly the same quantity of bristle in it as a corresponding brush; great care being taken not to disturb the way in which the bristles lie. They must all point one way, and naturally they have a certain bend. The outside of the brush is usually made of white bristles, while the inside is grey and yellow. This is almost a universal rule, for although the inside bristles are of equal spring to those outside, still trade demands white bristles outside and has them. The reader will understand that the bristles that are to form the ground brush about to be made are lying on the scale, these having been weighed they are taken off, the white bristles being underneath, so as to form the outside of the brush. The workman takes all the bristles carefully, but firmly, in both hands, and turns the bristle round his thumb in such a way that the bend of the bristles all turn inward towards the centre, and the white bristles or ‘cappings’ lie in an even rim round the rest, and the ‘knot’ is then tied round with string. The knots are then dipped in hot cement and kept warm standing upon a hot plate.
The next process is ‘driving,’ which consists in forcing the handle through the bristles, which has been previously inserted in its binding, and this tightens the brush by compression.
Varnish brushes, as a rule, are shaped in a manner somewhat similar to the method of making artists’ pencils, that is to say, the wedge shape is produced by placing the bristles into a small circular box, the bottom of which is concave. Hence, it will be seen that the bristles, if even they are all of the same length, have the necessary chisel-edge for a varnish brush. Pegged brushes are made under a patent of Messrs. G. B. Kent & Sons. Speaking roughly, it consists of driving pegs into the back woodwork of the brush so as to throw the parts into greater compression and to hold the bristles tighter. After the brush is made, the bristles are thoroughly scoured on a stone with soap and water. After the brush is finished, the bleaching chambers are reached where, by means of sulphurous fumes, the bristles are bleached to the required degree of whiteness.
—However good a brush may be it will soon be ruined unless it is properly treated when out of use. The following hints will suffice as a guide in this respect:—
Writing Pencils, etc.—Wash in turpentine until quite clean, and if they are not to be used for some time dip in olive oil and smooth from heel to point.
RED SABLE.
RED SABLE.
Stipplers.—Wash thoroughly in pure soap and hot water rinsing with cold water. Place point downwards to dry.
STIPPLER, WITH BRIDGE HANDLE.
STIPPLER, WITH BRIDGE HANDLE.
Varnish Brushes.—The best method of keeping varnish brushes, in the opinion of the author, is to suspend them in the same description of varnish as that they are used for. As this is not always possible boiled oil may be used instead.
VARNISH BRUSH—GALVD. WIRE BOUND.
VARNISH BRUSH—GALVD. WIRE BOUND.
Paint Brushes.—Mr.Ernest N. Kentgives the following instructions in “Specificationsâ€:—
SASH TOOL.
SASH TOOL.
FLAT OVAL GROUND BRUSH.
FLAT OVAL GROUND BRUSH.
Brushes made for Use in Colourshould first be soaked wellin water to swell the bristle in the binding. This applies also to whitewash brushes which are bound either by wire or leather.
A Brush after Useshould be thoroughly cleansed out in turps or soap and water. If left in water any length of time they are liable to twist, and the bristles lose their elasticity.
A Brush made for Paintshould not be used in varnish, the spirit of which dissolves the cement with which it is set, and loosens the bristles. When a ground brush has been well worn down in colour, it may, however, be used in varnish.
A Brush made for Varnishmust on no account be put into water as the water destroys the cement.
Varnish Brusheswhen not in use should be suspended in either varnish or oil, the brush not resting on the bristles. No brushes should on any account be kept in turpentine.
Stippling Brushesshould be well cleaned and dried after use, the bristle being carefully kept from crushing; a box in which they can be slid, allowing the bristle to hang downwards is recommended.
Should a Brush become quite hard with Paintit should be soaked for twenty-four hours in raw linseed oil, after which time in hot turpentine.
—Take 2lbs. of ground litharge, 2lbs. of red lead, 1lb. of sulphate of manganese,1â„2lb. of sugar of lead. Mix these to a paste with light coach japan, put the paste into a gallon jar and add half a gallon of pure turpentine. Let this stand for three days, stirring occasionally, then pour off the resultant liquid which forms first-class terebine. You can afterwards pour in another half gallon of turps, well stir and pour off as before. This can be done a third time when the chemicals will have become exhausted.
—A cement suitable for filling up defects in cast iron is made by mixing one part of bone black, one part of powdered gum arabic, one part iron dust or very fine iron filings, and two parts of plaster of Paris. This powder is made up into a stiff bodywith water, but only sufficient for immediate use should be made, as it sets very rapidly. In time it becomes as hard as iron.
—The following mixture will produce an excellent buff paint for ordinary purposes. Grind in raw linseed oil 3cwt. of white lead, 4cwt. of grey barytes, 8lbs. of genuine red oxide, 100lbs. of J.F.L.S. ochre, and 8lbs. burnt Turkey umber.
—Grind together 5cwt. of grey barytes, 1cwt. Paris white, 4cwt. of French ochre, and 4lbs. of genuine red oxide of iron.
—Dissolve rosin in an equal bulk of naphtha and colour with lamp black for black, celestial blue for blue, Venetian red for red, and so on. A little oil added will be of assistance.
—Dissolve asphaltum in spirits of turpentine and thin down to the required consistency.
This class of paint is much used in America, and they are made in a variety of colours. The necessary qualities are great durability under wear. Three coats are usually given, but it is very necessary that sufficient time be allowed to elapse between the application of each coat to enable a thorough drying to be effected. The thinners for each recipe will be the same, namely, gloss oil twenty gallons, linseed oil eight gallons, turpentine japan six gallons, benzine japan two gallons, turpentine four gallons, benzine three gallons, making together 52 gallons. The pigments will be as follows:
—Yellow ochre, 175lbs.; whiting, 25lbs.; zinc, 25lbs.; Portland cement, 3lbs.
—Zinc white, 175lbs.; white lead, 25lbs.; whiting, 50lbs.; lamp black, 1lb.; yellow ochre, 8lbs.
—The same as dust colour, excepting that 5lbs. of lamp black should be used and 3lbs. of yellow ochre.
—Yellow ochre, 100lbs.; Venetian red, 17lbs.; zinc, 25lbs.; whiting, 70lbs.
—Indian red, 100lbs.; Venetian red, 50lbs.; zinc, 25lbs.; whiting, 25lbs.
—Yellow ochre, 100lbs.; whiting, 70lbs.; mineral brown, 15lbs.; zinc, 25lbs.; Venetian red, 6lbs.
This class of paints is much used in the United States, the article that is to be painted being dipped into the paint so as to save the labour of applying it with a brush in the ordinary manner.
—In this case two separate dippings are required, first with the following mixture which acts as a primer. Take 100lbs. of dry ground slate, 100lbs. of whiting, 50lbs. of zinc white, 2 gallons of linseed oil, 20 gallons of gloss oil, and 5 gallons of benzine. These being properly mixed form a priming coat which dries fairly quickly. When dry dip the article into a paint made of the following mixture: 25lbs. of drop black, 31â„2gallons of grinding japan, half gallon of turpentine, 71â„2gallons gloss oil, and one gallon of turpentine.
—A primer is made by grinding together 14lbs. of golden ochre, 11â„2gallons of grinding japan, 2 gallons of gloss oil, and half gallon of turpentine. The paint is made of 30lbs. of medium chrome yellow, 2 gallons of grinding japan, 11â„2gallons of turpentine, and 7 gallons of gloss oil. This makes 12 gallons of paint.
—Grind together 80lbs. of bright scarlet or Turkey red, 80lbs. best Paris white, 38 gallons gloss oil, 4 gallons of benzine, 2 gallons of linseed oil, and 2 gallons of benzine japan. This makes 50 gallons of paint.
—Grind together 100lbs. of dry ground slate, 25lbs. zinc white, 1 gallon of linseed oil, 2 gallons of gloss oil, and 1 gallon of japan drier.
—Grind 100lbs. of zinc white with 90lbs. of Paris white in 2 gallons of linseed oil, 32 gallons of gloss oil, and 11 gallons of benzine. This makes 50 gallons of paint.
The above recipes for dipping paints have been modified from recipes which originally appeared in “Drugs, Oils and Paints,†of Philadelphia.
There has been a very considerable amount of difference of opinion as to the best paint for iron. An elaborate course of experiments were made and the results reported in the columns of the “Engineer†some time since. The results of theseexperiments showed that no rust whatever resulted from either of the following mixtures, which may therefore be recommended as good paints for iron.
—Red lead, 88 parts; raw linseed oil, 12 parts.
—Cheaper red lead, 45 parts; barytes, 45 parts; raw linseed oil, 10 parts.
—Very cheap red lead, 22 parts; barytes, 66 parts; raw linseed oil, 12 parts.
—Barytes, 33 parts; deep vermilionette, 44 parts; pale vermilionette, 14 parts; raw linseed oil, 7 parts.
—Permanent red, 88 parts; raw linseed oil, 7 parts.
Although an ordinary putty is made of dry whiting with raw linseed oil, a modification of this mixture is often necessary and desirable.
—One pound of white lead mixed with 10lbs. of whiting and ground with the necessary quantity of boiled linseed oil makes an excellent putty. About half a gill of best olive oil or cotton seed oil added, prevents the white lead from hardening and preserves the putty in a state sufficiently soft to adhere at all times.
—The above recipe answers for putty that is to be sent abroad, the cotton oil preventing it from going hard. Sometimes the white lead is omitted.
—A very strong putty is made of boiled oil and whiting and is suitable for exposed positions, such as skylights. It is not adapted for keeping, as it gets too hard. Putty for inside work that is ground in raw linseed oil may be made by adding a little white lead.
—Mix dry red lead with boiled oil and turpentine varnish. This may be used immediately, as it soon gets hard.
—Boil 7 parts of linseed oil with four parts of brown umber for two hours. Then add 51â„2parts of whiting and 11 parts of white lead and mix the whole. This putty is very durable and adheres well to wood.
—Various recipes for a so-called imperishable putty have been given. The one published above, named French putty, is very durable, but it may be varied by boiling together for two hours 31â„2lbs. of linseed oil and 2lbs. of brown umber. Stir in one ounce of beeswax, take off the fire, and mix 2³â„4lbs. of whiting and 51â„2lbs. of white lead.
—Dissolve glue in water and add as much very fine sawdust as may be required.
—Mix 5 oz. of lamp black and 3 oz. of superfine flour of emery in half a gallon of shellac varnish or patent knotting. This gives a fine slating. Shellac varnish may be made by dissolving 1lb. of orange shellac in half a gallon of methylated spirits. Another recipe is: Dissolve 1lb. shellac in one gallon of methylated spirits. When dissolved add 1lb. best ivory black, 5 oz. of best flour of emery. Mix and put in a stoppered bottle, shake well before using. In applying this it must be done rapidly, and only a little of the paint should be poured out at a time, as the spirit rapidly evaporates. In applying it to old blackboards one coat is usually sufficient.
—In order to prevent the breeding of vermin the whitewash used for poultry houses should be mixed with a little gas tar—not coal tar. It may be obtained at any gas works, and should be used in the proportion of about a quarter of a pint to the pailful of ash. To bind the whitewash, flour made into a paste with hot water may be used, and is better than glue size as it does not decay and will not injure the fowls.
An excess of driers in paint often gives rise to blistering.
Boiled oil, if of good quality, will, when applied to glass, dry in 24 hours.
Tar should always be applied hot.
Dark boiled oil may be pure, but it will not produce good work.
A little varnish added to paint, often improves both its appearance and durability.
In painting over bad stains, tar, etc., a coat of shellac varnish will usually give a good surface on which the paint will dry.
Ochre makes a good and cheap priming coat, if it is very fine.
To test patent driers, mix it with raw linseed oil, in the proportion of one to three, and apply to glass. If still tacky at the end of 24 hours, the driers may be looked upon as being of inferior quality.
Varnish brushes are best kept, when not in use, by being suspended in the same kind of varnish in which they are ordinary used.
For thinning gold size, use a little boiled oil, not turpentine.
The practical painter should have an “educated†nose—that is, one that can at once detect adulteration in oil and turpentine.
To mix varnishes is sometimes necessary, when the particular kind required is not at hand. But it is always a bad plan, and is never desirable. When it must be done, do not use the varnish for a few days.
An even temperature is of the greatest importance in obtaining good results from varnish. Coach painters’ shops are usually kept exactly at the same heat, while dust and draughts of cold air are rigidly excluded. This is one of the reasons why coach painters are able to turn out such fine work.
Success in repainting ironwork largely depends in removing allrust, scale, etc. For this purpose, wire brushes should be used, as they greatly facilitate the operation.
Luminous paint which, if exposed to the light during the day, will give off sufficient light at night time to enable one to see the time by a watch, may be had to last several years, if protected by a piece of glass from the weather, and it is extremely useful for certain positions where it is not desired to burn a light.
Fineness of grinding is a most important quality of all tinting colours, but in none more so than in the umbers and siennas prepared for grainer’s use. It is of equal importance that the tone and colour be pure. Sometimes this class of colours are toned up with chrome, but this is objectionable, and the right tone of sienna can only be expected when the correct quality of crude earth is selected.
Tube colours are now becoming so popular among the highest class painters and decorators that the use of dry colours will soon be considered obsolete. When the colours are put in tubes, waste is almost wholly prevented, while their use keeps the colours moist for a considerable time.
Two coats of patent knotting or shellac varnish may be given to cover stains, damp spots, or other work which will not take the paint. Even tar spots thus treated may be neutralized.
Grained work should never be varnished until after 6 or 7 days from the time it is finished. This delay will render the surface much more durable than it would be if varnished immediately.
Spring and summer are not the best for painting, as many suppose. The autumn is better, as the work is then, as a rule, thoroughly dry and in the best condition to take the paint.
To obscure window glass, the best plan is to apply a coat of matting varnish, which is specially made for the purpose. It looksvery neat, and effectively obscures the glass, although it shuts out very little of the light.
A rough way of testing a brush is to pluck a few bristles and to burn them by applying a match. If they are true bristles they will give off an unmistakable odour, will frizzle up while burning, but will not leave an ash. Fibre, on the other hand, burns without smell, and leaves an ash.
Embossing on glass is usually done by means of hydrofluoric acid. The design is pounced or sketched on with French chalk. Then every part that is not to be embossed is painted over with a special Brunswick black. A little wall of tallow is then built all around the pane of glass laid flat, and the acid is gently poured on. In about half an hour it has eaten into the glass sufficiently to form a well-defined pattern. The acid is poured off into a guttapercha bottle, the tallow removed, and the surface washed with clean water. The black is softened with turpentine and removed by means of an old chisel.
A priming coat can never prove satisfactory unless it is composed of very fine materials. White lead, red lead, or white lead and ochre are among the best primers.
The best tests of linseed oil for the practical man are the senses of smell and taste. The analysis of linseed oil is a very difficult process, and every oil dealer should educate his senses by constant practice and recognise the pure oil immediately when he smells or tastes it. Adulteration in boiled oil is more difficult to detect than it is in raw oil.
Never mix two different kinds of driers in a paint; they may re-act upon one another and actually retard the drying of the paint.
Too much driers in paint will destroy its durability and may affect the gloss.
Messrs.Wilkinson, Heywood & Clark, Ltd., 7, Caledonian Road, London, N., have favoured the author with samples of their colours, which he finds, after examination, to be of a high order of excellence. Their white oil varnish is also highly recommended, being almost colourless and not turning yellow.
In preparing plaster figures for showing samples of gold paint it is necessary first to give a heavy coat of shellac to prevent absorption.
Perhaps not one painter in a thousand knows that water glass (silicate of soda) makes an excellent size for wall paper. It will not wash up the pattern, and it forms a foundation for the paper varnish that makes it stand out admirably.
The priming coat for new pine may be made by mixing a stone of white lead in oil with an equal quantity of patent driers. About one pound of turpentine and a pound and a half of raw linseed oil will be required.
—As already stated we cannot spare room to deal with this important subject, but may give one or two notes on the subject. The following is a useful list taken from “Colour,†byGeorge H. Hurst. A somewhat similar list will be found in “Colour†byProfessor A. H. Church. The names and addresses of the publishers of these two books are given on another page.
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