Birch Characteristics: Red, White, Curly Birch
Information on the types of birch wood, white, red, and curly birch, and their characteristics.
¶ Because of its very desirable qualities, birch is one of the most versatile of woods, being used for innumerable purposes in addition to its many uses in the building and furniture fields.
¶ Birch is a hard, close-grain, fine-textured wood. It is tough, strong and heavy. The heartwood is reddish yellow and the sapwood is yellow. The grain figure of birch shows great variety ranging from very plain, inconspicuous growth to the strong figures and the very ornate curly birch. When well seasoned, birch does not warp, twist, split or swell. Its very hard surface makes the wood withstand much abuse in the way of mars, bruises, scratches and knocks without showing ill effects. And, again, its very hard nature makes it possible to give birch an unusually high polish without a great number of surfacing coats. Birch is suitable for finishing in the natural color, for any stained color and for enamel finishes.
¶ The grades of birch are, unselected, red birch and curly birch. Unselected birch is a mixture of the reddish heartwood and yellow sapwood and a mixture of grain figures. It is suitable for stained finishes in dark colors and for painted and enameled finishes. Red birch is all reddish heartwood and is much used for trim, cabinets and floors. It is suitable for dark stained finishes, for painted and enameled finishes. When used for gray or other very light finishes a toner of light green aniline water stain should be spread on the wood first and allowed to dry. That will neutralize the reddish tone of the wood, making better grays and light browns from stains.
¶ Curly birch has a beautiful wavy grain figure which looks like watered silk. It is rather scarce because only an occasional tree is found to produce this peculiar grain. It is much used for furniture, cabinets, doors and panels. It costs more than the other grades, of course. Curly birch gives an impression of delicacy and is used on furniture which is to have the feminine appeal.
¶ White birch is the heartwood of the tree. It is generally light in color, but because it has a reddish tone also it is called red birch.
¶ For producing silver gray and other similar gray finishes, birch and white oak divide honors, especially if these woods are bleached do they make perfect finishes of this kind. Some object, however, to the yellowish tone which comes through the gray from the birch and prefer maple for grays.
¶ The stained finishes most commonly produced on birch are mahogany, red and brown, walnut, antique mahogany, fumed browns, produced with tannic acid washes and bichromate of potash solutions, and it also makes a close representation of cherry. In producing a cherry finish with birch take care not to allow a reddish tone to occur which real cherry doesn't have. The stain must be absolutely clear,no sediment or undissolved coloring matter should be permitted. It is best to use a strong, water-soluble aniline stain very thin. Add about 1 ounce of acetic acid to a quart of stain to secure increased penetration.
¶ Birch is a wood which sandpapers well and finishes up after sanding with a velvety lustre much admired. It has one peculiarity which is apt to give trouble to the inexperienced, however. The wood seems to grow in both directions at the same time,it has many areas where the end grain crops up. End grain takes stain darker than the balance of the surface unless the stain is very thin or unless the end grain is coated with very thin shellac or glue size before staining. Sometimes when looking at the finished birch from one end it looks uniform in color, but from the other end it looks darker. Uniformity of color is, of course, very desirable and more so for furniture and fine cabinet work than for the average run of wood trim. In the furniture factory uniformity of finish begins with the proper selection of each board as to color and grain and the way the wood is laid out to be glued and joined together. If a board which is too light accidentally gets into a piece of furniture that board is stained first to make it match up with the balance of the wood before the whole surface is stained. If the board is too dark it is bleached out before the staining is done.
¶ Birch is a close-grain wood, as has been said, and some finishers object to the use of a filler on it, claiming that it will muddy up or cloud the finish. That surely is true if a poor filler is used and especially if the stain is not wiped off clean, but if good fine silex (silica) filler is used, is properly tempered and made thinner than for oak and is wiped at the right time and wiped clean the beauty of the finish is enhanced by the filler. This is especially true when a dark or black filler is used to contrast with the stain color, as is true in producing mahogany. The wood cells or open parts of birch grain are very small, to be sure, but they offer some opportunity for the filler to lodge and so improve the finish. It is quite out of the question to produce the best kind of finish in silver gray without the use of pure white filler. Of course white paraffin wax can be used as a finish for silver gray and it will serve the purpose of the white filler to some extent.
¶ Those who object to using a paste filler on birch use one or two thin coats of shellac and rub each coat close, which practically removes all of the shellac except that which is lodged in the pores of the wood. These same finishers object to the use of filler on wall panels which are constructed with mahogany veneer center panels and birch stiles and mouldings. Their method of finishing such surfaces is to stain the mahogany and the birch with the first coat of stain. Then to fill the mahogany only and brush on a second coat of stain to the birch only to make it dark enough to match the mahogany. If the stain fails to take, to penetrate the birch, as it sometimes will, add 1 ounce of acetic acid, or more of strong table vinegar, to a quart of water stain. That will increase penetration of the stain.
¶ The weight of the argument, however, is in favor of using a dark paste filler, thinned more than for oak, in order to bring out the grain of the wood more effectively and make the open pores contrast with the stain color of the fibres.
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