Whitewash is the most purely white coating known; and it is sanitary, as the lime has a purifying action, kills germs, and does not act as a medium for their growth. It is on this account a good coating for cellar-walls and the like, also for the interior of stables and outbuildings in general. It may be colored with any pigments which are not attacked by lime; a yellow or cream color is obtained by adding yellow ocher; it will mix with any of the iron oxides, as Venetian red or Indian red, also with umber and sienna; and tints may be obtained with mixtures of these, with or without lampblack, as described in speaking of oil paints. Bright yellow and green cannot be made, but various dull colors are available. However, whitewash is generally white; and although the directions of the U.S. Lighthouse Board say to apply it hot, that is intended to apply only to the rather complex mixture which they recommend; common whitewash is used cold. It is not unusual to put a little carbolic acid in it for use in cellars, stables, and the like.
Whitewash brushes should be washed out immediately after using, as the caustic lime is not good for them. To determine how thick whitewash should be, it is customary to brush out a little of it on a piece of well-sized paper, which can be dried quickly; this will show if it covers sufficiently; if it is too thick the coating will look coarse and sandy.
Kalsomining
Kalsomine, or calcimine, is much like white-wash; it is a water-paint, having a lime as a base; but whereas whitewash is a mixture of fresh, caustic water- laked lime with water, and has enough adhesive quality to make it stick by itself fairly well, kalsomine is made of the carbonate of lime, or chalk ground to a fine powder and known as whiting, Paris white, or Spanish white, mixed not with pure water but with size, or a thin solution of glue, which is the binder. To make it, fifteen or twenty pounds ofwhiting are mixed withwaterenough to make a thick paste; half a pound of good white glue, which has previously been dissolved in water by the method already described, is added to it, and enough hot water is then added to make about one-fifth as many gallons as there are pounds of whiting; that is, five pounds of whiting make a gallon of kalsomine. When cool it will be a jelly, and is then ready for application.