primer
The primer (often by English primer , primer ' called) is used to protect the material by a first layer, while improving conditions for the application of further protective and decorative coatings. Materials on which coatings do not stick well are pretreated with an adhesion promoter or primer . Applications can be found in various areas of artistic, manual or industrial material and paint application.
Also impregnations are often classed as primers. Impregnations usually penetrate deeper and close the pores, while a primer can have various tasks.
While primers are consistently referred to as primers in the English-speaking world , primers in German tend to mean substances that chemically prepare the substrate, i.e. that are applied before the primer. Often no clear distinction is made between primers, adhesion promoters, primer and primer. Basically, all of these substances should mediate between the substrate and the coating.
Woodworking
Woodworking is traditionally primed with half oil . Half-oil was probably used in ancient times. Fresh wood can be sensitive to dirt - depending on the type of wood and moisture content , perspiration can leave stains on the skin. Wood products from the joinery usually receive at least one primer coat before delivery. The linseed oil closes the pores and vacuoles of the wood somewhat. Subsequent coats of paint penetrate less deeply into the wood, which means that multiple applications can be avoided. (Safety advice : linseed oil products can lead to spontaneous combustion of used rags and not washed out brushes if exposed to air . These are therefore to be kept in closed containers or under water.)
Softwoods for outdoor use are mostly given a blue stain protection as their first order.
Metal construction
Most metalworking processes involve pre-treatment before the final paint application. In the automotive sector, for example, a corrosion protection primer is applied to the bare metal, which leads to very good adhesion to the metal and thus prevents or at least slows down corrosion. Then, if necessary, the surface is shaped with filler and then smoothed with filler . If no filler is required, primer and filler can also be applied in one step (primer filler). Only after the filler is lacquer applied. Topcoat can be used for less stressed indoor areas, while for exterior paintwork one or more layers of basecoat are applied and finally clearcoat, possibly also several layers.
building
Before applying thin layers of plaster and before painting walls and ceilings, highly absorbent substrates are pretreated with a deep primer (also deep primer), usually based on alkyd or acrylic resin . Certain primers can also strengthen sanding plasters or chalking layers. Pre-spray plaster is used as a bonding agent and to compensate for unevenly absorbent surfaces before plastering .
In wallpapering , waste traditionally describes an under-wallpaper made of waste paper and paste, which should reduce the absorbency of the surface and compensate for unevenness in the wall. Blocking primer (also insulating paint or barrier paint ) is used to prevent discoloration such as rust, nicotine, water or soot stains from penetrating . Adhesion promoters for the application of sealants, such as silicone compounds , are often referred to as primers .
art
In panel painting , the primer is the first layer that lies directly on the substrate. It consists of a filler / pigment and a binder . It should level out the unevenness of the picture carrier, create a good connection between the carrier and the paint layer and influence the appearance of the painting. A primer can consist of several layers. Pre-gluing and imprimitur are part of the primer. The primer is usually applied with a brush and sanded after drying.
Painting science distinguishes between white and colored primers. The white primers consist of plaster of paris (gypsum base), chalk (chalk base) or white lead (white lead primer) and a binding agent. In the case of the fillers plaster of paris and chalk, the binding agent is usually glutinous glue, in the case of white lead a drying oil. The colored grounds ( bolus ground ) usually consist of unfired or burnt ocher with a drying oil as a binding agent. Since mid-20th century also come resin - dispersions as binders for fillers for new application such. B. ready-to-use aqueous acrylic primers.
The recipes for various artistic painting grounds and primers can be found in painting tracts and painting books .
development
The technical structure of the primer changed over the centuries. In medieval painting, the primer was multi-layered and thicker than the paint layer. Later it slowly became thinner and lost its function as a reflector of light, which was so necessary in the 16th century. In the 17th century, it was mainly used as a “pore filler”, only to be replaced by the thicker imprimitur, which practically assumed a double function. It was not until the painting of the 19th century that it returned to its original function. In the same century, the machine production of pre-primed canvases developed (pre- priming ). Until the 16th century, white primers were used almost exclusively in European panel painting.
In the case of the wooden sculpture , the primer is the bottom layer of the frame directly on the wooden body. Its structure largely corresponds to that of the white primer in panel painting .
literature
Kurt Wehlte : Materials and techniques of painting. Arranged by Hajo Düchting . Seemann, Berlin 2001, ISBN 3-332-01665-2 ; Englisch-Verlag, Wiesbaden 2009, ISBN 978-3-86230-003-7 .
Individual evidence
- ↑ Knut Nicolaus: DuMont's picture lexicon for determining paintings . DuMont Buchverlag, Cologne 1982, ISBN 3-7701-1243-1 , p. 97 .
- ↑ Knut Nicolaus: DuMont's picture lexicon for determining paintings . DuMont Buchverlag, Cologne 1982, ISBN 3-7701-1243-1 , p. 97 .