The Building Industry

Wanganui Chronicle, Volume LXXXI, Issue 19049, 28 June 1924, Page 14

The Building Industry

WOOD STAINS THEIR USE AMD MIS USE. Staining is rlic artificial colouring of wood to enhance its natural ance, to give to new w r ood the semblance of age, or to make a cheap wood resemble another and more expensive wood. A stain properly made and applied should not hide or cover any of the grain or pores of the wood, but on the contrary should distinctly show the markings of the surface and bring out the beauty of the wood to its fullest extent.

Most woods, if exposed a sufficient length of time, will change colours to some degree. Many will greatly change by ageing. It is, therefore, perfectly legitimate to use a stain to impart this appearance of age to new wood. It is also quite proper to stain a cheap wood to give it the appearance of a more expensive wood, but hero the painter must realise that each wood has a distinctive grain and to simply stain a pitch pine, for instance, which has a large, coarse grain to the colour of mahogany, which has a fine delicate grain does not always work out satisfactory. Birch, on the contrary, can be stained to represent mahogany with good success because its grain' corresponds closely with the grain of mahogany. The improper use of stains is to impart to wods colours which, do not belong to them, such as blues, greens, etc., simply to make them harmonise with the draperies and furnishings of the room. Water stains arc made from colouring materials, which are soluble in water and are held in high esteem by the old school painters who used them before oil stains came into general use. They have the virtues of deep penetration and clear toned colouring. On rough or very porous lumber which | would absorb too much oil stain and, I in consequence, turn too dark, water stain can bp used to advantage. It can be applied more quickly than an oil stain and dries quickly enough to stand varnishing or shellacking in half an hour.

It has the fault of raising the grain of the wood, but this is overcome by some mechanics by wetting the surface with clear water and sandpapering smooth when dry. The water stain can then bn applied and will raise the grain but little. A thin coat of shellac over the water stain will sometimes sand down the grain. The best way to apply water stain is with a sponge. It dries so quickly that if applied with a. brush it is almost sure to show laps. Spend is essential to a. good job of work done with water stain, and the quicker it is applied the better the work will bp. Spirit stains arc made from colouring matter soluble in alcohol. They penetrate deeply and dry rapidly. Thev are used considerably for fine cabinet work, but to no great extent bv house painters. They do not raise the grain of the wood as water stain does, but give the same rich toned colours. A job may be stained, shellacked and varnished in one day, for in this regard spirit stain is excellent for small work, but it dries so rapidly that it is difficult to avoid laps on large surfaces. They may bo finished in shellac and waxecL or varnished as desired.

Varnish stains are simply a mixture of varnish and colouring matter, and are supposed to eoniplete the two operations of staining and varnishing with one application. They have but little penetration and dry slowly. Seldom used except in small quantities to refirish articles of furniture, or to touch up a marred surface. They are not generally used for good work or for large jobs.

Chemical stains, sometimes called acid stains, are used to produce novol effects in woods by changing the colour of the wood through, chemical action. Woods containing tannic ac’d can be chemically treated to produce the effect of age, as when oak is exposed to the fumes of ammonia which turn it to a very rich brown. They arc not much used by painters but are used to some extent by furniture manufacturers.

Oil stains are about the most, permanent, are easy to apply, do not raise the grain or show laps. They may not be quite so bright as some of the spirit or water stains, but are far more permanent to colour. While they do not penetrate as deeply as some other stains yet this is sometime's rather s. benefit as when it is desirable to change the colour. Oil stains are used mostly on the softer woods w r hich do not require a filler, as pine, birch, cypress, beech, etc. While it is fairly satisfactory on hard woods, a more penetrating stain gives better results. Oil stains dry more slowly than others and sometimes appear to be dry when in reality they are not. If sufficient time is not given it for thorough drying the varnish applied over it may become tacky. Because of its ease of application and good working qualities it has become a general favourite among painters for nearly every class of work. A painter’s first thought when about to do a job of wood staining is to make sure that the surface is perfectly clean and free of dust, lime, dirt or finger marks'. It is sometimes necessary to clean these marks with benzine or by scraping, but generally sandpapering will bring the surface to a

proper condition. No stain should ever be applied until the surface is as clean and smooth as it is possible to make it. Wood stains will set as fast or faster than flat paint and the same care and general method of working them is necessary. Stains should be applied carefully but quickly with a good wire flat brush. On new untreated wood this quick setting of stains is most apparent. If the wood is given a coat of turpentine and oil, about 75 per cent, of the former to 2 5 per cent, of the latter, an oil stain may be applied and will not set so quickly. This, of course, applies to only very porous or soft woods. The painter should exercise care to avoid laps showing on his work. On wooden partitions the workman should do no more than two or three boards at a time, cutting in neatly along the edge of the last board. On doors or other panelled worked the panels should be stained first, including the moulding around the edge, taking care not to run over on to the stiles. The dividing rails between panels should bo done next, cutting in sharply along the end of the- board. Next the edges of the door and finally tho outside stiles. With a quick setting stain it is almost impossible to avoid laps and dark, spots if the stain has been ’run over on to another part of the work.

It is obvious that to apply a brush- I fuLof stain to the middle of a board ' or panel gives two edges to keep wet in- ’ stead of one edge if the work -was started at the end of the board or panel. The best tool for applying stains is a four-inch wall brush whichhas been worn to a chisel edge. On every job some pieces of wood will be found harder than the average, i while others may be softer. On the j harder portions the stain will not penetrate so deeply and these places will show lighter in colour. Reversely, I the softer parts will take more stain ' and show darker. This can be over- ! come by having two or three pots of j stain of different consistencies, applying the heaviest to the hard and the thinnest to the soft woods. Some painters prefer to give the harder spots an extra coat of stain after the firstcuat has dried, and wipe surplus stain from the softer parts to bring them to a uniform colour. Almost every stain will make a bet-| ter looking job by letting it set for a I few minutes and then wiping the sur-1 plus stain off with a cloth, it brings out the grain of the wood more dis- j tictly and dries far more evenly, j When this is done, the softer parts, which have taken in more stain and j show' darker can be wiped out with a cloth moistened with benzine.

Painters are frequently called on to stain a surface which has been varnished or painted. No stain will penetrate such a surface and it is necessary to remove the old finish and cleat! and sandpaper the surface to a new condition as nearly as approximately new wood as possible. Some of the woodwork may need scraping with the edge of broken glass or a steel scraper in order to strip off the old paint, or shellac. A gasoline torch cannot be used for removing as the heat chars and discolours the wood. Even with all this work it is better to use a thinner and more penetrating stain than for new wood. Some cheap jobs are done on old surfaces by giving them a ground coat of flat paint of the proper colour and applying a varnish or an oil stain over it, with a flat stippler, imitate the grain of the wood. A very attractive finish is described in the new Painters’ Text Book as follows: “A novelty finish is often used on oak, chestnut, and ash. which have an open grain. The general appearance of the wood is gray, rather a salt and pepper effect. But actually no stain is used. “The raw wood should, bo coated with boiled linseed oil only: After the oil is dry, clean the pores of the wood free from dust. Thon simply fill . the wood pores with light gray paste filler, or with whitelead paste just as it comes in the keg. The filler is used very thick—thin it enough with turpentine to spread over with a putty knife and scraped off again. And a little japan drier. Put the filler on plentifully, rub it in with a stubby brush and then scrape, of the excess with a putty knife. Let the filler set an hour or so and wipe off any excess on the surface, being careful not to drag it out of the pores of the wood. Let dry two days.

Next, sandpaper, wipe off the surface clean and put on a coat of white wax' Rub the wax to a dull lustre. If a gloss finish must be done, use instead of the wax, a coat of white shellac, then varnish. Shellac and varnish will in time turn the gray to a brown. “Sometimes a gray stain is used in addition to filling the wood pores with a white filler. This makes a permanent job.”—“Carter Times.” f