Finishing and Refinishing Wood, Oil Finishing, Staining and Weathered Effects
( Originally Published 1937 )
WHETHER you make new things of wood, restore old ones or merely "fix up the house" you will find a knowledge of finishing materials useful. The out-line given below emphasizes the effects of old natural wood and warm colors. I shall not discuss paint, enamel or varnish because full directions are printed on their containers. Richness is obtained by bringing out the natural qualities of a wood, not by disguising them. The earth colors given below are suitable for tinting wood because they resemble wood colors. Avoid the use of unnatural stains, and do not try to make one wood imitate another.
The beauty of furniture and woodwork is revealed by removing its old paint or varnish and exposing the natural wood. Apply the paint remover with a brush, let it soak a few minutes and scrape with tools that fit the surfaces. Finish with steel wool dipped in remover.
You need not be alarmed on viewing the endless lists of oils, thinners, gums and pigments that are available for treating woods. You can do perfectly good work with quite a limited selection. Some merely replace one another and many are merely cheaper and inferior substitutes. Here is a list of materials that may be used to make up a simple finisher's kit:
Boiled linseed oil Dryer
The most generally useful will be ground in oil, but you may occasionally require either dry colors or colors ground in coach Japan. If in doubt or limited to a small outlay get powder colors.
Lamp Black Raw Umber
A liberal supply of clean rags is necessary. NOTE WELL:—Oily or painty rags are a great source of danger from spontaneous combustion. They should never be allowed to accumulate or even to lie on the bench overnight, but should always be burned or buried or covered with water.
How TO CLEAN YOUR BRUSHES
Do not get the habit of standing brushes in water but always clean them out as soon as you stop working with them. If they have been used in oil stains, paints or varnishes, use kerosene or clear gasoline, if spirit stains or shellac use alcohol, if in lacquers use the thinner. This is how you do it: Pour out into an open vessel sufficient of the liquid to dip the brush in. Having dipped it, do not stir it around but quickly withdraw it and hold it upside down a moment so that the liquid may run down into the roots of the bristles. Now put the brush into your piece of rag and wipe it well. You should repeat this until the liquid comes perfectly clean out of your brush, leaving no stain on the cloth. Brushes should be occasionally washed in soapy water. Rub them on the cake of soap working up a lather. Then work them against the side of a basin or on a board, forcing the lather into the roots of the bristles. Repeat until the lather comes out perfectly clean and white, then rinse thoroughly and draw the bristles to the proper shape before setting aside to dry.
It is a great nuisance to clean shellac brushes and if they are not thoroughly cleaned they dry up quite stiff and useless. Moreover, shellac is needed so frequently around the workshop that it is desirable to have a brush that is kept in the bottle. This is very simple to arrange. Take a marmalade bottle holding about a pint and whittle a stopper for it out of a piece of soft pine. See that it is a perfect fit. Then cut out a groove or notch in the side of it that just fits the handle of your brush, keeping the brush up a little off the bottom of the bottle. When using the brush. just lay the stopper aside.
Wax polishes are useful for protecting surfaces of all kinds. The ingredients are varied according to the kind of exposure the surfaces will receive. Polishes for cars, for example, need to be very hard and bright and so should contain a large proportion of carnauba wax. Wood floors, on the other hand, re-quire a tough elastic finish and the polish should contain a tempering ingredient such as beeswax and possibly a little boiled linseed oil, although the latter will be slower in receiving a lustre. Where a natural wood finish is desired, the wax may be applied directly. For woodwork, paneled walls, and furniture, this preserves the natural colon of the wood, if you prefer it to the darker shade brought on by treatment with oil. However, it is not wise to treat floors this way because of the wear they get. To floors apply at least one coat of equal parts of boiled linseed oil and benzine or else a coat of filler.
When the filler has dried, apply a thin coat of shellac and then wax. The filler is made of silex, color, linseed oil and turpentine. Apply it with the grain of the wood, and after it has soaked in rub it off across the grain with rags or waste.
Wax polishes usually have beeswax as a base, and for most purposes there is nothing better. Where you want a harder, more brilliant shine, carnauba wax is introduced, and if you need to lower the cost you substitute a certain amount of paraffin wax. These waxes are melted in a water bath or double boiler and then the pot is removed from the stove and the solvent, usually turpentine or benzine, is added. Turpentine makes a tougher film but benzine and gasoline dry more quickly. An example Is the following:
Carnauba wax 3 oz, Beeswax 5 oz. Turpentine 1 qt. Benzine 1 pt.
Adjust proportions of thinner, if too soft or stiff when cold.
For applying the wax to floors tie it up in a cloth bag, and squeeze it through the bag as you rub it.
For finishing pine and cypress table tops and draining boards for sinks I have found the following treatment unexcelled.
1. Sand perfectly smooth with 0 and 2/0 sand-paper.
2. Apply a liberal coat of raw linseed oil at night.
3. In the morning wipe off any unabsorbed oil.
4. Repeat this every night until no more oil is absorbed. Then continue rubbing with a little oil every day until the surface has a soft sheen all over it.
5. Allow it to harden for several days.
6. Keep it waxed and polished.
Wood finished in this way may be scrubbed with soap and water, and will resist the acids of fruit and vegetables.
Floors may be treated the same way, if the wood is new, clean and free from grease. Another way of treating floors to get a similar effect is to brush the oil on liberally and follow immediately with a vigorous rubbing with a weighted polishing brush. This treatment should be kept up all day long, with one man continually applying the oil and another polishing. Resume work the next day, if necessary, and continue until the floor will absorb no more oil and dries with a soft sheen. It takes a lot of oil, a lot of rubbing, and is rather expensive for large floors. Do not forget to wash the oil out of the weighted brush with gasoline or kerosene.
Linseed oil (raw or boiled) shaken well with shellac in equal parts, makes a good rubbing polish for all kinds of work. It is particularly good for finishing things on the lathe. Be sure that the wood is perfectly finished with the tools and sandpaper first. Apply it with a cloth while the work is revolving at the slowest speed. It will quickly build up a soft polish. For a glassy polish let it dry for a day or so between coats and build up coat after coat until it is as you want it. Or use shellac painted on in successive coats and rubbed down with powdered pumice and linseed oil on a felt rubber, in between coats. If you prefer a soft eggshell finish, substitute water for the oil. But for the very finest high gloss, finish with rottenstone and oil.
Old wood on interior walls takes a soft rich sheen if rubbed with crude oil. The main ingredient here is the rubbing rather than the oil—and this is true of most finishes—there is no substitute for elbow grease.
The finish left by rubbing with paint remover and steel wool is often very satisfactory, there being enough wax in the remover to leave a soft shine if well rubbed.
STAINING AND WEATHERED EFFECTS PIGMENT STAINS
These owe their color to solid pigments mixed with a suitable medium, usually boiled linseed oil, turps or benzine and drier. You can make oil pigment stains by mixing any of the colors given with such a medium using either dry colors or colors ground in oil. The latter will be easier to mix. Shingle stains are made the same way but usually have some creosote for a preservative, and kerosene for a thinner as well as oil. Dark shingle stains may be made by dissolving tar or pitch with kerosene, adding oil, and creosote if desired. Old crankcase oil is even used. If this is allowed to settle it becomes clear and is useful to protect rough wood floors, not to be waxed.
These are usually aniline dyes that are applied in various solvents:
Spirit stains: These spirit soluble dyes can be purchased from your wholesale chemist, and dissolved in alcohol to the strength required.
Water stains: These may be purchased as water stains for wood, or purchased as water soluble dyes (such as Diamond Dyes) and mixed to suit your purpose. Alcohol added to the mixture helps it to spread more evenly into the wood. The natural vegetable dyes, particularly the barks, leaves and chips (see page 184) are suitable for making water stains.
Oil stains: Oil soluble dyes are frequently used in oil stains supplemented by pigments.
Chemical stains: In these a chemical combines with substances in the wood, or substances deposited there by another chemical, to form a color right in the. wood. Ammonia added to a water stain will give it more "tooth" so it can "bite in." The chemicals given in the section on dyeing fabrics—potassium bichromate, alum, acetic acid, etc. may also be applied to the treatment of wood. Oxalic acid is used for bleaching. Slaked lime for yellow effects, potash for gray, and potassium permanganate for old pine. This is a very effective stain. Throw a handful of potassium permanganate crystals into a pail and half fill it with water. Add a pint or so of alcohol, and apply with a brush. Only enough of the crystals will dissolve to keep the solution saturated, and more liquids can be added as it is used up until the crystals are all dissolved. As you apply the stain you can use your judgment in matching the tones—if you need the stain a little darker, dip the brush down nearer to the crystals. When the stain is dry it should be waxed.
Wood treated with water and chemical stains requires sandpapering after it is dry. Stained wood should be protected with wax, oil, or shellac.