Aerosol paint

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Aerosol paint can. Propellant in the top of the can pressures down on the paint propellant mixture in the bottom. The paint mixture is pushed up through the dip tube when the valve is opened.

Aerosol paint (also called spray paint) is a type of paint that comes in a sealed pressurized container and is released in a fine spray mist when depressing a valve button. A form of spray painting, aerosol paint leaves a smooth, evenly coated surface, unlike many rolled or brushed paints. Standard sized cans are portable, inexpensive and easy to store. Aerosol primer can be applied directly to bare metal and many plastics.

History[edit]

In 1949, Edward Seymour added paint to existing aerosol can technology at his wife Bonnie's suggestion. It was initially designed to demonstrate an aluminum paint he developed.[1][2]

Most aerosol paints also have a metal, glass or plastic ball called a pea inside of the can, which is used to mix the paint when the can is shaken.

Uses[edit]

A typical paint valve system has a "female" valve; the stem is part of the top actuator. The valve can be preassembled with the valve cup and installed on the can as one piece, prior to pressure-filling. The actuator is added after.

Commercial, industrial and consumer uses[edit]

Acrylic-based craft primers and vinyl dye can be used on plastics like models or miniatures.

Most brands include a wide variety of paints, including primers, heat and traffic resistant enamels, gloss and matte finishes, metallic colors, and textured paints for home decor.

Aerosol paint is useful for quick, semi-permanent marking on construction and surveying sites. Inverted cans for street, utility or field marking can be used upside-down with an extension pole. APWA (American Public Works Association) has standardized colors for utility and excavation markings. Hiking trails can also be marked with aerosol paint trail blazes.

Small to medium-sized repairs to automobile bodywork can be completed by enthusiasts at home using aerosol paint, although to paint an entire vehicle in this way would be difficult and expensive. The main disadvantages, compared to professional sprayguns, are the limited quality offered by the built-in nozzle and the lack of infra-red baking after applying the paint, which means the paint can take several months to achieve its final hardness.

Technique[edit]

For a good finish it is essential to prepare the surface well, sanding to provide a key and thoroughly degreasing with naptha (panel wipe). Areas not to be painted should be masked, although for repair work it is important to avoid spraying a full coat right up to the masking tape, which will leave a hard line; it is better to fade the new paint into the existing paint, especially if the colour is a difficult one to match. The flow of paint should be started or stopped on the masked area rather than over the area to be painted, as aerosols often discharge "blobs" of paint under these conditions. Coats should be built up lightly enough to avoid runs, but a "dry" finish must be avoided by spraying too thinly or from too far away. The optimum distance between the can and workpiece is around one foot (30 cm). Most automotive paints will require a clear lacquer after the colour coat, normally 24 hours later. The colour coat should be well matted down with very fine abrasive paper before applying the lacquer.

Graffiti and street art uses[edit]

Main article: Graffiti

Speed, portability and permanence also make aerosol paint a common graffiti medium. In the late 1970s, street graffiti writers' signatures and murals became more elaborate and a unique style developed as a factor of the aerosol medium and the speed required for illicit work. Many now recognize graffiti and street art as a unique art form and specifically manufactured aerosol paints are made for the graffiti artist.

Graffiti artist paints tend to be more expensive, but have a wider selection of rich colors, are thicker and less likely to drip. They are produced in standard high pressure cans for fast, thick coverage and lower pressure cans for more control and flexibility. Most art brand paints have two or three mixing peas in a can. A wide array of actuators, or caps are available, from standard "skinny" caps to wider "fat" caps, as well as caps that control the softness or crispness of the spray. Calligraphy caps create fan spray instead of the standard round.

Stencils[edit]

Spray paint graffiti tags on a dumpster with the owner's markings spray painted using a stencil. New York City, 2007.
Main articles: Stencil and Stencil graffiti

When aerosol paint is used, care must be taken to cover or mask areas where paint is not wanted. A stencil can be used to protect a surface except the specific shape that is to be painted. Stencils can be purchased as movable letters, ordered as professionally cut logos, or hand-cut by artists.

Stencils can be used multiple times for recognition and consistency. Official stencils can be used to quickly and clearly label objects, vehicles or locations. Graffiti writers can use stencils to quickly mark in busy places or leave recognizable tags over a large area. Stencil artists often use multiple colors, or create elaborate stencils that are works of art in themselves.

Illicit use[edit]

Graffiti[edit]

Graffiti is considered a crime in most jurisdictions. The UK and many US cities prohibit the sale of aerosol paint to minors as part of graffiti abatement programs.[3] While major industrial and consumer aerosol paint companies like Krylon and Rust-Oleum actively participate in anti-graffiti programs, art-brand companies are often supportive of writers and graffiti culture, though most do not endorse illegal writing.

Inhalant[edit]

Like many household chemicals and aerosols, aerosol paint vapor and propellant can be misused as an inhalant.

See also[edit]

References[edit]

External links[edit]