Wood Furniture Finishing : Oak, Maple & Gumwood
The best methods and techniques for finishing Craftsman furniture, and staining wood generally, are gone over here by Stickley including finishing of oak, maple, and gumwood.
Finishing Oak Wood
¶ The work of construction must all be done before the wood is given its final finish; but in this connection we will outline briefly the best method of finishing oak, as the sturdy wooden quality of the furniture depends entirely upon the ability of the worker to treat the wood so that there is little evidence of an applied finish. Oak should be ripened as the old mahogany was ripened by oil and sunshine, and this can be done only by a process that, without altering or disguising the nature of the wood, gives it the appearance of having been mellowed by age and use. This process is merely fuming with ammonia, which has a certain affinity with the tannic acid that exists in the wood, and it is the only one known to us that acts upon the glossy hard rays as well as the softer parts of the wood, coloring all together in an even tone so that the figure is marked only by its difference in texture. This result is not so good when stains are used instead of fuming, as staining leaves the soft part of the wood dark and the markings light and prominent.
¶ The fuming is not an especially difficult process, but it requires a good deal of care, for the piece must be put into an air-tight box or closet, on the floor of which has been placed shallow dishes containing aqua ammonia (26 per cent). The length of time required to fume oak to a good color depends largely upon the tightness of the compartment, but as a rule forty eight hours is enough. When fuming is not practicable, as in the case of a piece too large for any available compartment or one that is built into the room, a fairly good result may be obtained by applying the strong ammonia directly to the wood with a sponge or brush. In either case the wood must be in its natural condition when treated, as any previous application of oil or stain would keep the ammonia from taking effect. After the wood so treated is thoroughly dry from the first application it should be sandpapered carefully with fine sandpaper, then a second coat of ammonia applied, followed by a second careful sandpapering.
¶ Some pieces fume much darker than others, according to the amount of tannin left free to attract the ammonia after the wood has been kiln dried. Where any sap wood has been left on, that part will be found unaffected by the fumes. There is apt also to be a slight difference in tone when the piece is not all made from the same log, because some trees contain more tannic acid than others. To meet these conditions it is necessary to make a "touch-up" to even the color. This is done by mixing a brown aniline dye (that will dissolve in alcohol) with German lacquer, commonly known as "banana liquid". The mixture may be thinned with wood alcohol to the right consistency before using. In touching up the lighter portions of the wood the stain may be smoothly blended with the darker tint of the perfectly fumed parts, by rubbing along the line where they join with a piece of soft dry cheese cloth, closely following the brush. If the stain should dry too fast and the color is left uneven, dampen the cloth very slightly with alcohol. After fuming, sandpapering and touching up a piece of furniture, apply a coat of lacquer, made of one third white shellac and two thirds German lacquer. If the fuming process has resulted in a shade dark enough to be satisfactory, this lacquer may be applied clear; if not, it may be darkened by the addition of a small quantity of the stain used in touching up. Care must be taken, however, to carry on the color so lightly that it will not grow muddy under the brush of an inexperienced worker. The danger of this makes it often more advisable to apply two coats of lacquer, each containing a very little color. If this is done, sandpaper each coat with very fine sandpaper after it is thoroughly dried and then apply one or more coats of prepared floor wax. These directions, if carefully followed, should give the same effects that characterize the Craftsman furniture.
¶ Sometimes a home cabinetworker does not find it practicable or desirable to fume the oak. In such a case there are a number of good stains on the market that could be used on oak as well as on other woods.
Staining with Shellac
¶ Oak and chestnut alone are susceptible to the action of ammonia fumes, but in other ways the oak, chestnut, ash and elm come into one class as regards treatment, for the reason that they all have a strong, well defined grain and are so alike in nature that they are affected in much the same way by the same method of finishing. For any one of these woods a water stain should never be used, as it raises the grain to such an extent that in sandpapering to make it smooth again, the color is sanded off with the grain, leaving an unevenly stained and very unpleasant surface. The most satisfactory method we know, especially for workers who have had but little experience, is to use a small amount of color carried on in very thin shellac. If the commercial cut shellac is used it should be reduced with alcohol in the proportion of one part of shellac to three of alcohol. This is because shellac, as it is ordinarily cut for commercial purposes, is mixed in the proportion of four pounds to a gallon of alcohol, so that in order to make it thin enough it is necessary to add sufficient alcohol to obtain a mixture of one pound of shellac to a gallon of alcohol. If the worker does his own cutting he will naturally use the proportion last mentioned, one pound of shellac to a gallon of alcohol. When the piece is ready for the final finish, apply a coat of thin shellac, adding a little color if necessary; sandpaper carefully and then apply one or more coats of liquid wax. These directions are entirely for the use of home workers. The method we use in the Craftsman Workshops differs in many ways, for we naturally have much greater facilities for obtaining any desired effect than would be possible with the equipment of a home worker.
Finishing Maple & Gumwood
¶ For lighter pieces of furniture suitable for a bedroom or a womans sitting room, where dainty effects are desirable, we find maple the most satisfactory, in both color and texture, of our native woods, for the reason that it is hard enough to be used for all kinds of furniture. Gumwood, or gum wood, is equally beautiful, but is not hard enough for chairs. For built in furniture, however, and for tables, dressers and the like, gumwood is one of the most beautiful woods we have, as it takes on a soft, satin like texture with variable color effects not unlike those seen in the finest Circassian walnut. We find that the best effect in both maple and gumwood is obtained by treating the wood with a solution of iron rust made by throwing iron filings or any small pieces of iron into acid vinegar or a weak solution of acetic acid. After 48 hours the solution is drained off and diluted with water until the desired color is obtained. The wood is merely brushed over with this solution, wetting it thoroughly, and left to dry. This is a process that requires much experimenting with small pieces of wood before attempting to treat the furniture, as the color does not show until the application is completely dry. By this treatment maple is given a beautiful tone of pale silvery gray and the gumwood takes on a soft pale grayish brown, both of which colors harmonize admirably with dull blue, old rose, straw color, or any of the more delicate shades so often used in furnishing a bedroom or a womans sitting room.
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