Techniques > Systems > Finishes > Media >


Whitewash Man, RA Photo Club (Bill Young)

   Whitewash is slaked quicklime, at times combined with pigment. It dries through crystal formation. In combination with a proteinaceous (protein-based) binder, quicklime (or inert lime) is not a whitewash but a water-based, water-soluble paint -- usually a distemper, calsomine or milk paint.
   Whitewash has been used for millennia. It is found as a major treatment in 17th- to early 20th-century houses as a wall and ceiling treatment; on wood, plaster, and masonry; for protection, sanitation, and as a decorative treatment. While a paint, whitewash is prepared -- and usually used -- by masons, as the process of making whitewash involves slaking quicklime, employed for mortar and cement.

   "Whitewash. An inexpensive white coating for rough work on walls or ceilings. It is neither permanent nor waterproof. The term usually refers to lime mixed with water, but calcimine and other cheap water paints may also be called whitewash. Whitewash has been used in the past to impose artistic censorship by hiding mosaic and fresco mural decoration for religious and political reasons. Many such works have been reclaimed in modern times, by simply washing away the coating."
Mayer, Ralph, Dictionary of Art Terms and Techniques, New York: Barnes & Noble Books, 1981, first published in 1969, p.431.

   "Whitewash: white fluid commonly used as an inexpensive, impermanent coating for walls, fences, stables, and other exterior structures. It varies in composition, being generally a mixture of lime (quicklime), water, flour, salt, glue, and whiting, with other ingredients such as molasses, water glass, or soap sometimes added. Mixed with size and colored, whitewash is occasionally used on interiors as calcimine."
The Columbia Encyclopedia
, Sixth Edition, 2000.

The folowing recipes are cited from Nineteen Ninety Five Paint Questions Answered, New York: The Painters Magazine, 1923

1270 — Whitewash for Interior Walls and Ceilings, p.462

   A.B., New Bedford, Mass., writes:- I should like to have some information regarding interior whitewashing. I whitewashed some ceilings with good slaked lime that was slaked for two or three days before. The first coat worked all right, but the second coat crawled and spotted all over the sidewalks [sic], and yet the third coat was again all right. In another case I had the ceiling peeled a day or two after it was dry. Can you account for this?
  Answer:- Always slake your lime with boiling water and cover the tub or barrel with sackcloth or burlap to keep the steam. When the lime has all broken up keep it covered with water; never let it dry up., for then it becomes useless. After you have thinned down your slaked lime to the right consistency for application add two more tablespoonfuls of salt to each pail of the wash, also one pound of flour, previously mixed with hot water, stirring it thoroughly. This will give good binding property to the wash and keep it from peeling, nor will it rub off when dry. If the wash is to be thin one-half pound of flour to the pail will be sufficient, especially when it is going on a sandy wall.
   If the whitewash works poorly or comes out spotted. one ounce of potash alum dissolved in water and added to a pail of whitewash will correct the trouble, but too much alum is liable to make the whitewash scale. A good, hard drying whitewash that will not crack or peel can be made by slaking thirty pounds of builders' lime with hot water, keeping in the steam for at least twelve hours. When diluted add to the wash two pounds of zinc sulphate and one pound common salt previously dissolved in water. It is not good practice to use glue as a binder for whitewash, and at any rate if the glue is not first class or has not been dissolved thoroughly, it will make the wash crawl and spot as you have stated. If you have to whitewash any surface, wall or ceiling that has been greasy it is best to wash it first with vinegar before applying the whitewash. It is an important point that brushes, pails, etc., are clean, and the wash should be strained.

#1259 - Whitewash as Specified by the U.S. Government, p.458

   The recipe for mixing whitewash according to government specifications was wanted.
   Take of fresh Rosendale cement 3 parts by measure, of clean, fine sand 1 part by measure, mix with fresh water very thoroughly. This makes a sort of granite color, dark or light, according to the color of the cement and sand. If the color is desired nearly white, use two parts fresh lime, slake this first, then add 1 part cement and 1 part white sand. For a brick red color, Venetian red is added first to the mixture; for buff color yellow ocher is added. The wash must be made as thin as can be conveniently applied with a whitewash or large kalsomine brush. Before applying the wash, the surface must be wet with clear water, so as to give the wash an opportunity to hold out until it sets. It is admirably adapted for brick and stonework or rough fences, but will not work over paint or whitewash. It should be kept well stirred during application.

#1257- Whitewash for Exterior Surfaces, p.458

   Take one-half bushel of freahly burnt lime and slake it with boiling water, cover it over during the slaking so as to keep in the gases that are generated. Sift the mixture through a fine sieve, and add to it seven pounds of salt previously dissolved in sufficient warm water; three pounds of ground rice boiled to a thin paste and stirred in boiling hot , half a pound of powdered Spanish whiting, one pound of glue (which has previously been dissolved by soaking it well and then heating it in a glue pot); add five gallons of hot water to the mixture, stir it well, and let it stand a few days covered free from dirt. It must be put on quite hot; for this purpose it can be kept in a vessel over a portable furnace. About one pint of this wash will cover one square yard.
  A simpler whitewash is prepared by mixing to a batter half a pound of wheat flour with cold water, and making it into a paste by pouring on it boiling water to thicken it, a pour this paste into a pailful of lime and water which has been mixed in the ordinary way of whitewash. Stir it all well together.
H.C. Standage.

Whitewash, p.762

A formula used by the United States Government in making whitewash for light-houses and other public buildings is as follows:

Unslaked lime...... 2 pecks
Common salt....... 1 peck
Rice flour........... 3 pounds
Spanish whiting... 1/2 pound
Glue (clean and
white.............. 1 pound
Water, a sufficient quantity.

   Slake the lime in a vessel of about 10 gallons capacity; cover it, and add the salt previously dissolved in warm water. Boil the rice flour in water; soak the glue in water and dissolve on a water bath, and add both, together with the whiting and 5 gallons of hot water to the mixture, stirring all well together. Cover to protect from dirt, and let it stand for a few days, when it will be ready for use. It is to be applied hot, and for that reason should be used from a kettle over a portable furnace.

General Directions for Preparing Whitewash.
   In general, virtually any type of quicklime or hydrated lime may be used in the preparation of lime paste with the following formulas. However, generally hydrated lime is preferable, but when hydrate is used best results are obtained from the more highly refined types of commercial hydrates which contain virtually no coarse particles or lumps. Specifically, these more refined types of hydrated limes are known as chemical hydrate, agricultural spray hydrate, finishing lime, and pressure hydrated lime. The use of such limes is particularly important when the whitewash is to be applied with a spray pump or paint gun in order to prevent the nozzle on the sprayer from being clogged. Otherwise, it is necessary to strain the lime paste made from quicklime and unrefined hydrated lime through a fine screen in order to remove the coarse particles. In any event, it is always advisable to follow the lime manufacturer's directions on slaking the quicklime or soaking the hydrated lime. Approximately 8 gallons of stiff lime paste are produced by slaking 38 pounds of quicklime with 8 gallons of water, or by soaking 50 pounds of hydrated lime in 6 gallons of water.
  After water is added to the mix the final whitewash mixture should be thin, resembling the consistency of whole milk.

Whitewash Formulas.
   While lime alone with water for whitewashing can be used in some instances, the durability of such a mixture will generally be improved by adding other materials to the mix. The following formulas are divided into two groups: (1) those formulas which are simpler to prepare, but which have produced satisfactory results and (2) more detailed formulas which are satisfactory and may even produce better results than those listed in the first group.
I. Simpler Formulas

1. Salt........................15 lbs.
   Lime paste.................8 gals.

Dissolve the salt in about 5 gallons of water and add this solution to the lime paste. Mix thoroughly and thin to desired consistency with fresh water.

2. Calcium chloride (dry)...5 lbs.
    Lime paste.................8 gals.

The substitution of calcium chloride for the salt in formula (1) produces a mixture that does not chalk and is quite durable. The same mixing directions apply.

3. White portland cement...25 lbs.
    Hydrated lime.............25 lbs.

   Both the cement and lime should be added together in dry form to about 8 gallons of water. After mixing thoroughly a thick slurry will result. Additional water should then be added until after further agitation the mixture resembles the consistency of heavy cream. Do not mix more than can be used in a few hours.
Note. The above weight proportions are approximately equivalent to one part of cement to 2 parts of lime by volume.

II. More Detailed Formulas.

4. Casein......................5 lbs.
    Household water softener
    (Trisodium phosphate).3 lbs.
    Formaldehyde............3 pts.
    Lime paste................8 gals.

   Soak the casein in about 2 gallons of hot water until thoroughly softened (about 2 hours). Dissolve the water softener in 1 gallon of water, add this solution to the casein, and allow the mixture to dissolve. Dissolve the formaldehyde in 3 gallons of water. When the lime paste and the casein solution are thoroughly cool, slowly add the casein solution to the lime, stirring constantly.
Just before using slowly add the formaldehyde solution to the batch, stirring constantly and vigorously. Care must be taken not to add the formaldehyde too rapidly as this may cause the casein to form a jelly-like mass, thus spoiling the batch. Do not make up more of this formula than can be used in one day as it may deteriorate.
   This formula is recommended highly for most uses, as the coating is white and is quite weather-resistant.

5. The addition to 1 to 2 pounds of calcium chloride to formula (3) will improve the results slightly. The calcium chloride should be dissolved in a small amount of water and added and stirred into the cement-lime mix just before using.

6. Skimmed milk.............5 lbs.
    Formaldehyde.............3 pts.
    Lime paste.................8 gals.

   This formula is a favorite of some dairy farmers for whitewashing the walls and ceilings of barns. Here, skimmed milk largely replaces water as the solvent. After mixing the skimmed milk thoroughly with the lime paste, add the formaldehyde slowly, stirring vigorously. Add water until desired consistency is obtained.

8. Casein......................5 lbs.
    Borax.......................3 lbs.
    Lime paste.................8 gals.

Soak the casein in 4 gallons of hot water until thoroughly softened (about 2 hours). Dissolve the borax in 2 gallons of water and add this solution to the casein. When both are cold, slowly add the borax-casein solution to the lime paste, stirring constantly and vigorously. Thin to the desired consistency. Do not prepare a larger quantity of this formula than can be used in one day as it may deteriorate.

9. The addition of 1-1/2 to 2 pounds of titanium dioxide or zinc sulfide (opaque white pigments) to any of the above formulas will improve the appearance of the whitewash when it is wet as well as help to retain the "dead" white effect for longer periods. The opaque white pigment should be mixed thoroughly with the lime paste.

Applying the Wash.

   Whitewashes and lime paints should be applied thin, and the surface should be dampened so that the coating will dry gradually. In fact, best results will be procured if the application is so thin that the surface to which it is applied may be seen easily through the film while it is wet. The coating will dry opaque, however, and the thin coat will give better results than a thick one. A second thin coat may be applied over the thoroughly dry first coat if a whiter surface is desired. These cold water preparations can be applied easily and satisfactorily with a large brush. Do not attempt to brush out the coating as is done with oil paint, but simply spread it on as evenly and quickly as possible. The whitewash should be stirred frequently while it is being applied to prevent settling.

Whitewash & Cold Water Paints, Washington, DC: National Lime Association, copyright 1955, 15 pp., ref: pp.5-8.

  © 2002-2012 Heritage Stewardship     contact