Staining may be defined as coating with a coloring matter which changes the hue without obscuring the grain or texture.
It is accomplished either by the use of transparent colours or chemical action, or both. When, as is generally the case, it is applied to woodwook, the colouring is, or should be, limited in range to such colours as are common to woods, or are suggestive of wood.
Artistic instinct revolts against the fashion now in vogue among some classes, of staining woods in crude greens and steely greys, mauves, and peacock blues. These colours do not impart that structural solidity or importance to wood-work that is natural and proper. It is not at all necessary that the colour used should be the actual colour of any particular wood, as long as it is not so far removed from a woody colour as to be altogether unlike wood. Thus a bright red or an olive green, are not colours which we find reproduced in any actual wood, but they are so nearly allied to wood colours that they do not do violence to one’s sense of propriety.
Staining may be roughly divided into at least four classes Water staining, oil staining, spirit staining, and varnish staining.
In addition to these, staining is used decoratively to produce various ornamental effects. French polishers have a few other names for certain processes which are worthy of note viz., chemical staining, water coating, improving, ingraining, mottle staining, overgraining, &c. These devices are, however, seldom used by painters, but might be usefully em- ployed with more frequency.
Water Staining is the application of aqueous coloured solutions obtained from colouring substances soluble in water and having no body in them, as walnut juice, logwood extract, gamboge, turmeric, indigo, the juice of berries and bark of trees, and some pigments having little or no body, as Prussian blue, burnt and raw Sienna, Vandyke brown, and alkaline dyes.
Chemical Staining is the use of aqueous solutions not in themselves having colour, but which change the colour of the woods to which they are applied, as soda, lime, potash, ammonia, various sulphates and salts.
Water Coating is the use of body colours ground in water, as ochre, Umber, Venetian red, chrome, drop black, &c. It is in reality a form of distempering, differing, however, in the fact that it is not all left upon the wood to dry. Size is added to bind the colour, as in distempering. This process, of course, hides the natural grain of the wood somewhat, and disguises its shortcomings and defects.
Oil Staining is, as its name implies, the use of oil colours of a more or less transparent nature, as the Siennas, Vandyke brown, Prussian blue and brown, and the aniline and cochineal lakes. Varnish Staining consists in the use of varnish with the oil stains described in the last paragraph. The varnish is added to stop absorption, and prepare the work for varnishing or surface polishing.
Spirit Staining is akin to oil staining, but certain aniline and other dyes are more tractable and more easily miscible in spirit than in oil or water mediums, and are consequently used in this form. Improving is a term used to denote a mere brightening of the actual colour of the wood, without changing its hue. It may be accomplished by either or any of the staining processes used singly or in combination.
Natural Graining is the adding to the wood more markings, in order that plain pieces may be made fuller of interest and richer in grain. It does not imply a change in the kind of wood. All the processes used in ordinary graining, as mottling, pencilling, and overgraining, are resorted to in this operation.
Oak and other hard woods are often wax stained and polished by hand. Wax stains are made from a mixture of beeswax and turpentine, and oil colours, such as Vandyke brown, burnt Sienna, &c. They are applied freely when warm, and when well soaked in and hardened, say in twelve hours, a fine dull eggshell polish is produced by briskly rubbing with a hard shoe brush,or a roughish piece of jute canvas.
Spirit stains evaporate so quickly, as to require great expertness in handling in order to avoid patchiness and unequal depth. Varnish stains are only useful where economy is of more importance than durability, and when a high finish is not requisite. A comparison between the different classes of stain shows that the most durable stain is an oil stain.
This has a protective as well as a decorative value, and the oil, by reason of its slowness in drying, penetrates very deeply into the pores of the wood. Water stains are likely to raise the grain in the wood, and roughen its surface. They enhance the appearance of the grain if it be good, as the resinous parts resist the action of the water, and remain in strong contrast with the softer and spongy portions. They dry quickly and are inexpensive.
Polishing or varnishing can be done upon all the different classes of stain. The processes are dealt with under the head of Varnishing. The great desiderata in staining are clarity, evenness, and depth. Application of Stains. Large brushes should be used, and the work saturated and brushed in, so that the wood takes as deep a colour as the colour of stain used will make it.
It is always better to err on the light side in making up the stain, as the work can always be gone over again to deepen it further. It is difficult to evenly manipulate a very deep stain on white wood in one coat. A flat duster or a softener may be used to remove brush marks and keep the stain even. It will sometimes be necessary to stain wood in such a way as to subdue or partially hide the natural markings. This can be well done by the use of oil stains, and stippling, or flogging it while fully wet, and before it has entirely soaked in.
Water staining upon new wood-work should be done upon the unprepared wood as it has left the plane, and without glass papering. It will require sizing prior to varnishing, if the varnishing is to be limited to one or two coats ; but the work will be more durable if the sizing be omitted, and a further coat of varnish given instead.
Resinous woods, such as pitch pine, should be oil stained, or varnish or spirit stained, and not sized before varnishing. In varnishing woods in their natural colour, sizing may be used either before or after the first coat of varnish, to assist in stopping the absorption, or a coat of thin knotting may be used first instead of the size.
Varnish only is, however, the best for transparency and durability. This will necessitate at least three, generally four, coats of varnish. Cheap and fairly good finish may be secured by twice sizing and once varnishing.
When staining floors they must first be thoroughly cleansed. After washing in the ordinary way, dilute oxalic acid may be used to remove stains of ink or iron rust, &c. Floors should always be oil or beeswax stained, so that the stain penetrates well into the wood .
Oil stained floors can be varnished, but beeswax stain must be polished with beeswax and turpentine and a stiff, short shoe brush a somewhat laborious and costly process for the housekeeper. It is necessary that whatever is used, the wood should be thoroughly well saturated. Sizing and knotting preparatory to staining is not to be recommended, as, if this is used, the stain will chip off and tread up white and shabby-looking in a short time.