Whitewash, calcimine, kalsomine, calsomine, asbestis or lime paint is a type of paint made from slaked lime (calcium hydroxide, Ca(OH)2) or chalk (calcium carbonate, CaCO3), sometimes known as "whiting". Various other additives are sometimes used.
Whitewash, calcimine, kalsomine, calsomine, asbestis or lime paint is a type of paint made from slaked lime (calcium hydroxide, Ca(OH)2) or chalk (calcium carbonate, CaCO3), sometimes known as "whiting". Various other additives are sometimes used.
![Whitewashers, photographed by Nicolae Ionescu [cs], 1928 Nicolae Ionescu - The Whitewashers, 1928.jpg](http://upload.wikimedia.org/wikipedia/commons/thumb/e/e5/Nicolae_Ionescu_-_The_Whitewashers%2C_1928.jpg/220px-Nicolae_Ionescu_-_The_Whitewashers%2C_1928.jpg)
Whitewash cures through a reaction with carbon dioxide in the atmosphere to form calcium carbonate in the form of calcite, a type of reaction generally known as carbonation or by the more specific term, carbonatation.
It is usually applied to exteriors, or interiors of rural dairies because of its mildly antibacterial properties. Whitewash can be tinted for decorative use and is sometimes painted inside structures such as the hallways of apartment buildings. A small amount can rub off onto clothing. In Britain and Ireland, whitewash was used historically in interiors and exteriors of workers' cottages and still retains something of this association with rural poverty. In the United States, a similar attitude is expressed in the old saying "Too proud to whitewash and too poor to paint." [1] The historic California Missions were commonly whitewashed, giving them their distinctive bright white appearance.
Whitewash is especially compatible with masonry because it is absorbed easily and the resultant chemical reaction hardens the medium.[ citation needed ]
Lime wash is pure slaked lime in water. It produces a unique surface glow due to the double refraction of calcite crystals. Limewash and whitewash both cure to become the same material.
When whitewash or limewash is initially applied, it has very low opacity, which can lead novices to overthicken the paint. Drying increases opacity and subsequent curing increases opacity even further.
Limewash relies on being drawn into a substrate unlike a modern paint that adheres to the surface. The process of being drawn in needs to be controlled by damping down. If a wall is not damped, it can leave the lime and pigments on the surface powdery; if the wall is saturated, then there is no surface tension and this can result in failure of the limewash. Damping down is not difficult but it does need to be considered before application of the limewash. [2]
Additives traditionally used include water glass, glue, egg white, Portland cement, salt, soap, milk, flour, molasses, alum, and soil.
Whitewash is sometimes coloured with earths to achieve colours spanning the range of broken white, cream, yellow and a range of browns.
The blue laundry dye (such as Reckitt's "Dolly Blue" in the UK, Ireland and Australia, Loulaki in Greece, or Mrs. Stewart's Bluing in North America), formerly widely used to give a bright tinge to boiled white textiles, was a common 19th century addition.
Historically, pig's blood was added to give the colour Suffolk pink, a colour still widely used on house exteriors in some areas of the UK. If animal blood is applied excessively, its iron oxide can compromise the lime binder's strength.
Pozzolanic materials are occasionally added to give a much harder wearing paint finish. This addition creates a short open time and therefore requires timely application of the altered paint.
Linseed oil is sometimes added (typically 0.5-2%) to improve adhesion on difficult surfaces.
Cement addition makes a harder wearing paint in white or grey. Open time is short, so this is added at point of use. Cement restricts the breathable aspects of the limewash and is inadvisable for preserved historic buildings.
Dilute glues improve paint toughness.
Wheat flour has been used as a strength enhancing binder. Salt is often added to prevent mold.
Basic limewash can be inadequate in its ability to prevent rain-driven water ingress. Additives are being developed but these have the potential for affecting free vapor permeability. For this reason silicate paints, more common in Germany, are gaining popularity in the UK over limewash.
Whitewash is applied to trees, especially fruit trees, to prevent sun scald. [3] Most often only the lower trunk is painted. In Poland painting the whole trunk is also said[ citation needed ] to help keep the body of the tree cool in late winter and early spring months and hence help prevent fruit trees from blooming too soon, i.e. when warm sunny days could promote rapid tree warming, rising sap and bloom and intermittent frosty nights could damage outer tree rings and destroy the young buds and blossoms.
In the middle of the 20th century, when family farms with dairy barns were common in the Upper Midwest of the United States, whitewash was a necessary part of routine barn maintenance.
A traditional animal barn contains a variety of extremely rough surfaces that are difficult to wash and keep clean, such as stone and brick masonry, and also rough-cut lumber for the ceiling. If left alone, these surfaces collect dust, dirt, insect debris and wastes, and can become very dirty.
Whitewash aids in sanitation by coating and smoothing over the rough surfaces. Successive applications of whitewash build up layers of scale that flake off and, in the process, remove surface debris. The coating also has antimicrobial properties that provide hygienic and sanitary benefits for animal barns. [4]
Whitewash was painted on the internal walls of Royal Navy vessels during the Age of Sail to improve light levels inside a vessel's gundeck, reduce bacteria and prevent wear and tear on hull timbers. [5] It was also used during the Second World War by the German armed forces as an easy-to-apply winter camouflage for soft- and hard-skinned vehicles, aircraft and helmets. [6]
While calcimine was generally stable with oil paint, current latex paints blister and peel. No success has been reported with primers and other glues over top of a peeling wall. The only approach is to scrape it off. The chalk releases the paint in large flakes or small chips. While working, the wall sections of paint will appear to be solid and later come off easily. It is a long process.
The incident of Tom Sawyer whitewashing a fence as punishment is a famous image in American literature. It appears in The Adventures of Tom Sawyer written in 1876 by Mark Twain.
In the 1934 film, Fugitive Lovers , Madge Evans drops a bottle of cosmetics that she calls her "Calcimine".
Metaphorically, whitewashing refers to suppression or "glossing over" (possibly a close parallel construction) of potentially damaging or unwelcome information. In many Commonwealth areas, a whitewash refers to a game in which one side fails to score at all; the usage is especially found in cricket. [7]
Limestone is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of CaCO3. Limestone forms when these minerals precipitate out of water containing dissolved calcium. This can take place through both biological and nonbiological processes, though biological processes, such as the accumulation of corals and shells in the sea, have likely been more important for the last 540 million years. Limestone often contains fossils which provide scientists with information on ancient environments and on the evolution of life.
Paint is a material or mixture that, when applied to a solid material and allowed to dry, adds a film-like layer. As art, this is used to create an image or images known as a painting. Paint can be made in many colors and types. Most paints are either oil-based or water-based, and each has distinct characteristics.
Mortar is a workable paste which hardens to bind building blocks such as stones, bricks, and concrete masonry units, to fill and seal the irregular gaps between them, spread the weight of them evenly, and sometimes to add decorative colours or patterns to masonry walls. In its broadest sense, mortar includes pitch, asphalt, and soft mud or clay, as those used between mud bricks, as well as cement mortar. The word "mortar" comes from Old French mortier, "builder's mortar, plaster; bowl for mixing." (13c.).
Plaster is a building material used for the protective or decorative coating of walls and ceilings and for moulding and casting decorative elements. In English, "plaster" usually means a material used for the interiors of buildings, while "render" commonly refers to external applications. The term stucco refers to plasterwork that is worked in some way to produce relief decoration, rather than flat surfaces.
Calcium hydroxide (traditionally called slaked lime) is an inorganic compound with the chemical formula Ca(OH)2. It is a colorless crystal or white powder and is produced when quicklime (calcium oxide) is mixed with water. Annually, approximately 125 million tons of calcium hydroxide are produced worldwide.
Stucco or render is a construction material made of aggregates, a binder, and water. Stucco is applied wet and hardens to a very dense solid. It is used as a decorative coating for walls and ceilings, exterior walls, and as a sculptural and artistic material in architecture. Stucco can be applied on construction materials such as metal, expanded metal lath, concrete, cinder block, or clay brick and adobe for decorative and structural purposes.
Harling is a rough-cast wall finish consisting of lime and aggregate, known for its rough texture. Many castles and other buildings in Scotland and Ulster have walls finished with harling. It is also used on contemporary buildings, where it protects against the wet Scottish and Ulster climates and eliminates the need for paint.
In chemistry, efflorescence is the migration of a salt to the surface of a porous material, where it forms a coating. The essential process involves the dissolving of an internally held salt in water or occasionally, in another solvent. The water, with the salt now held in solution, migrates to the surface, then evaporates, leaving a coating of the salt.
Lime is an inorganic material composed primarily of calcium oxides and hydroxides. It is also the name for calcium oxide which occurs as a product of coal-seam fires and in altered limestone xenoliths in volcanic ejecta. The International Mineralogical Association recognizes lime as a mineral with the chemical formula of CaO. The word lime originates with its earliest use as building mortar and has the sense of sticking or adhering.
Hydraulic lime (HL) is a general term for a variety of lime different from calcium oxide, also called quicklime, that sets by hydration and consists of Calcium Silicate and Calcium Aluminate, compounds that can harden in contact with water. This contrasts with calcium hydroxide, also called slaked lime or air lime that is used to make lime mortar, the other common type of lime mortar, which sets by carbonation (re-absorbing carbon dioxide (CO2) from the air). Hydraulic lime provides a faster initial set and higher compressive strength than air lime, and hydraulic lime will set in more extreme conditions, including under water.
Lime plaster is a type of plaster composed of sand, water, and lime, usually non-hydraulic hydrated lime. Ancient lime plaster often contained horse hair for reinforcement and pozzolan additives to reduce the working time.
Silicate mineral paints or mineral colors are paint coats with mineral binding agents. Two relevant mineral binders play a role in the field of colors: Lime and silicate.
Plasterwork is construction or ornamentation done with plaster, such as a layer of plaster on an interior or exterior wall structure, or plaster decorative moldings on ceilings or walls. This is also sometimes called pargeting. The process of creating plasterwork, called plastering or rendering, has been used in building construction for centuries. For the art history of three-dimensional plaster, see stucco.
A plasterer is a tradesman who works with plaster, such as forming a layer of plaster on an interior wall or plaster decorative moldings on ceilings or walls. The process of creating plasterwork, called plastering, has been used in building construction for centuries. A plasterer is someone who does a full 4 or 2 years apprenticeship to be fully qualified.
Lime mortar or torching is a masonry mortar composed of lime and an aggregate such as sand, mixed with water. It is one of the oldest known types of mortar, used in ancient Rome and Greece, when it largely replaced the clay and gypsum mortars common to ancient Egyptian construction.
Cement clinker is a solid material produced in the manufacture of portland cement as an intermediary product. Clinker occurs as lumps or nodules, usually 3 millimetres (0.12 in) to 25 millimetres (0.98 in) in diameter. It is produced by sintering limestone and aluminosilicate materials such as clay during the cement kiln stage.
Distemper is a decorative paint and a historical medium for painting pictures, and contrasted with tempera. The binder may be glues of vegetable or animal origin. Soft distemper is not abrasion resistant and may include binders such as chalk, ground pigments, and animal glue. Hard distemper is stronger and wear-resistant and can include casein or linseed oil as binders.
Cement render or cement plaster is the application of a mortar mix of sand and cement, and water to brick, concrete, stone, or mud brick. It is often textured, colored, or painted after application. It is generally used on exterior walls but can be used to feature an interior wall. Depending on the 'look' required, rendering can be fine or coarse, textured or smooth, natural or colored, pigmented or painted.
Concrete is produced in a variety of compositions, finishes and performance characteristics to meet a wide range of needs.
The conservation and restoration of frescoes is the process of caring for and maintaining frescos, and includes documentation, examination, research, and treatment to insure their long-term viability, when desired.
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