SOME USEFUL HINTS ON PAINTS AND PAINTING.
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 all rust, 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 looks very 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.