Oil paint
Oil paint is a collective term for stains on the basis of drying oil as a binder.
Properties
In general, oil colors for artists in tubes are supplied as a paste. The toughness is slightly higher than in toothpaste and can be diluted with so-called mediums. Show on the tubes between 20 g and 400 g of one to five stars, the light fastness, and usually a square - either white, half or all black - the opacity of the color. Some artists mix their own oil paints and have direct influence on opacity and impasto.
Oil paint differs mainly in terms of drying time, for example, the acrylic and gouache paints. It is even in thin thicknesses in a few days and can be extended by special techniques to weeks. This feature is very important especially for large- scale works, and the wet-on- wet technique. In addition, can be revived within limits by special mediums slightly dried oil paint. The most common diluent for oil paint is turpentine. White spirit can be used as solvents.
Oil paints are characterized further by intense color impressions from, some of which ( eg, cobalt blue) already lie outside the color space of a photographic or typographic reproduction. The high lightfastness, opacity and durability are further advantages of the oil paints. Furthermore, the Deckraft the different pigments and is called semi-opaque, semi-transparent and transparent with opaque.
However, oil-based paint is a lot of experience in dealing with colors by the artist's advance, and the oil painting is not in vain as the supreme discipline in painting. The processing is complicated and precise planning of the work of art is needed - oil paintings require drying due to the correspondingly long pauses in their completion. Oil paints are suitable only for a very limited mixing techniques, as they are with only a few other types of color really tolerated due to the oil content - especially if they work on a water base. High demands are also placed on the canvas - here is again the oil the deciding factor. In most cases, screen or wood is used. Oil paint adheres well to these substrates, however, is very sensitive to mechanical deformations and scrolls therefore slightly.
For oil paints, the following drying and semi-drying oils are used in particular:
- Linseed oil
- Poppy-seed oil
- Walnut oil
- Hemp oil
- Sunflower oil
- Safflower oil
- Castor oil
- Perilla
- Tung oil (Chinese wood oil)
- Oiticica
The color pigments to the desired colors are applied to obtain the oil rub. To protect the oil layer colors in paintings a final varnish is also applied. The most common varnishes are soft resins dammar and mastic, which are replaced due to their yellowing process today by synthetic resins. Meanwhile, the industry offers the fast -drying alkyd oil colors are dry to the touch after a day. More recent developments include water- oil paints, are avoided by the solvent-based thinners.
Linseed oil paint for construction and crafts
For the production of oil paints for construction and crafts pigments with so-called " boiled " linseed oil are ground and mixed with 0.09 to a maximum of 3 % of dry matter. Provide the highest quality linseed oil paints without solvents and aromatics. You need to process no further additions, but can be diluted with boiled linseed oil if necessary. Since linseed oil paint is water resistant but vapor permeable, it is particularly suitable for outdoor use ( timber, timber cladding, doors, windows, shutters, wooden structures ), because moisture that has penetrated to damaged areas can evaporate again. So a rot and mold is prevented. Ageing linseed oil coatings should be maintained every five to eight years with cold-pressed, " boiled " linseed oil, depending on the weathering. If the paint after many years and several nourishing oil paintings fade, which is the case particularly in western and southern sides of buildings, it can be painted over. The old paint does not have to walk, but only be cleaned by brushing. In architectural conservation is of the monument authorities the application of traditional linseed oil paint without volatile organic compounds expected since pure linseed oil paint is made to a traditional recipe and thus falls back again on authentic historic paint and linseed oil - based primer. In addition, solvent-free linseed oil paint does not form layers that could flake off and they will not charge static, so they do not attract dust.