Mixing Stain, Stain Mix
How to mix stains, mixing stain tips and instructions guide.
¶ There are only a few additional points to keep in mind about the mixing, brushing and procedure in the application of stains. In the chapters treating each kind of stain the important considerations were discussed, but there are following some more points of general application.
¶ It has been suggested in preceding pages that the finisher ought to work by measure and not by guess. That takes more time but it pays to do it the first time or two, if not as an everyday practice. Put a label or tag on every stain mixture made, or keep a memorandum book to show the quantities of each ingredient used in mixing your stains. Then if you run short of stain you can easily and quickly duplicate the first batch exactly.
¶ When mixing by measure you will need the glass graduates, mortar and pestle, funnel and the balance scales illustrated in finishing tools. Then you will also have need of the following tables:
¶ U.S. Standard Weights & Measures
¶ Avoirdupois Weight.
27 H grains = 1 dram (dr.)
¶ Apothecaries Weights.
20 grains = 1 scruple
¶ Apothecaries' Fluid Measure
1 minim = 1 drop
¶ Liquid Measure.
4 gills = 1 pint
¶ Dry Measure
2 pints= 1 quart
¶ The many formulas given in this book may never be found to be exactly right because you may be using materials of greater or lesser strength than those used in testing out the formulas. They are, however, very close to the standard colors, or what are considered standard by many, and you should experience no difficulty because you will soon learn to temper any stain or to blend the various colors in your mixtures to produce the exact color tones wanted.
¶ Many things influence the color of a stained wood surface. Various boards of the same kind of wood, and even from the same tree, may finish up a slightly different color hue when using the same stain. And again you may have a stain which gives exactly the color wanted on birch, but put it on pine, gum or maple and quite another color hue may result on each kind of wood. So, to mix stain to match a sample you must spread it on the same kind of wood of which the sample consists. All of which simply goes to demonstrate the necessity for a finisher learning the exact characteristics of various stains on the many common woods. A good finisher can usually mix or temper a stain to make it match closely enough on two or more kinds of wood. By mixing his stain thinner or thicker, lighter or darker, by adding other colors or mixing two or more liquid stains of the same group or class and by wiping skillfully a finisher has complete control of results and can usually, but not always, produce the color wanted on any kind of wood. In a room trimmed with two or more kinds of wood it often is necessary to have two or more pots of stain tempered to fit each wood. Then, too, the preliminary treatment of the wood with acids or alkalies to change their chemical content before staining, or with oil or sizes to make the suction of the wood more uniform increases control of results. Veneered doors and panels with light and dark streaks can be made uniform by brushing on a coat mixed from 1 to V/2 ounces of bisulphite of soda dissolved in 1 pint of water. It will bleach out discolorations and make the whole surface lighter.
¶ The rougher the surface, naturally or from rough sandpapering with coarse paper, the darker the color produced by a stain. Rough surfaces soak up more stain. And smooth surfaces,naturally hard, close-grain, and those made smooth with fine sandpapering take the stain with a lighter color.
¶ To preserve and enhance the naturally beautiful characteristics of wood the stain substance or coloring matter dissolved in liquids should be completely soluble in the liquid used, that is, no coloring matter should remain in suspension, nor should any precipitate on to the bottom of the pot. Success in mixing to this extent means perfection and is the aim only for finishing fine furniture and cabinets. In the finishing of interior wood trim and cabinets of ordinary work the pigment oil or water stains sometimes used fail to meet this ideal because very little of the pigment coloring matter is really soluble in the liquids, they constitute merely a mechanical mixture of fine pigment with the liquid, the pigments remain in suspension. So when a pigment stain is being used the.pot should be stirred often to maintain a uniform mixture. Otherwise the coloring pigment will settle to the bottom and the color imparted to the wood will gradually become lighter.
¶ When water, spirit or oil aniline coal tar dye colors are used a good stain will remain clear at ordinary temperatures down to about 40 degrees. If at freezing temperature these stains show a settlement of coloring matter they should be heated, allowed to cool to 70 degrees and then they ought to be strained before using. If used while cold, strain them also or the color imparted to the wood will not be uniform. If you begin to spread such stains while warm do not allow them to drop to low temperatures or the color will get lighter as the stain gets colder. When you start a job one day with stain at a temperature of about 70 degrees, allow the stain to get very cold over night and begin using it next morning without warming, the color of the wood stained the second day will be lighter.
¶ The theory of crystallization is interesting as it concerns the solubility of anilines and other coal tar dye colors. To illustrate its working,a gallon of water at 70 degrees temperature may completely dissolve only say 2 ounces of a dry color of this type. It will remain clear with no precipitation and no cloudiness. You may let the temperature drop to 50, or even 40, degrees and still the stain will remain clear and hold the color in solution, showing no deposit of color on the bottom. Now if you raise the temperature to the boiling point, 212 degrees, you will find that at that temperature an ounce or so more of the color will be dissolved in the water, that the stain will remain clear and no deposit of color will be noticed on the bottom of the container. The coloring matter is completely in solution,a super-saturated solution, as it is called. Now allow the temperature to drop to 70 degrees again and the excessive load of color begins to precipitate to the bottom. And here is where the interest of the experiment begins,the crystallization goes on to the extent of throwing out of solution not only the extra one ounce of color added at 212 degrees but also some of the 2 ounces held in solution at 70 degrees before.
¶ The conclusion, then, to be drawn from these facts is that one ought not to mix a super-saturated stain solution unless you are going to apply the stain while hot.
¶ Any insoluble material thrown down in stain mixed at any temperature should be strained out before brushing it on to the wood. When this is not done the color may be streaked, cloudy or spotted. This insoluble material must be avoided especially in finishing with walnut browns of the water stain type. Of course, if you add more water to the stain the excess of coloring matter will be put into solution and that is. more economical because you then have more stain.
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