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Spray painting is a painting technique where a device sprays a coating
(paint, ink, varnish etc.) through the air onto a surface. The most common types
employ compressed gas — usually air compressed by an air compressor — to atomize
and direct the paint particles. Spray guns developed from airbrushes and the two
are usually distinguished by their size and the size of the spray pattern they
produce — with airbrushes being hand held and used instead of a brush for very
fine work such as photo retouching, painting nails or fine art.
1.1 Canned spray paint
1.2 Conventional paint
1.3 HVLP (High Volume Low Pressure) paint spraying
1.4 LVLP (Low Volume Low Pressure) paint spraying
1.5 Electrostatic spray painting
1.5.1 Rotational bell paint spraying
1.6 Electric fan paint spraying
1.7 Air Assisted Airless spray guns
1.8 Airless spray guns
1.9 Automated Linear Spray Systems
1.10 Automated Flatline Spray Systems
4 More Spray Painting Resources
paint gun Types
paint gun Canned spray paint
Main article: Aerosol paint
The most common type in the consumer market are cans of aerosol paint. A metal
aerosol can contains the highly pressurized paint which becomes atomized into a
fine spray when the paint is released through a valve operated by depressing it
with the finger. These aerosol cans are inexpensive, small, easily transported
and easily operated. This technology enabled and became synonymous with
graffiti, but it is also widely used by private persons for small paint work.
paint gun Conventional paint spraying
See also: Airbrush
A spray gun combines the coating (paint) and compressed air from a separate air
compressor in order to atomize the coating and direct it to the target surface.
The coating is held either in a small bottle or container attached to the spray
gun or in a separate pressurised container attached to the spray gun with a
hose. General rule of thumb is that this type of gun puts 1/3 of the coating on
the substrate being coated and 2/3 into the air.
paint gun HVLP (High Volume Low Pressure) paint spraying
This is similar to a conventional spray gun using a compressor to supply the
air, but the spray gun itself requires a lower pressure (LP). A higher volume (HV)
of paint is therefore applied at a lower air pressure. This results in more
paint landing on the target surface instead of staying airborne. A regulator is
often required so that the air pressure from a conventional compressor can be
lowered for the HVLP spray gun.
As a rule of thumb puts 2/3 of the coating on the substrate and 1/3 in the air.
True HVLP guns use 8 – 20 cfm and a minimum 5 hp industrial compressor is
required. HVLP spray systems are used in the automotive, marine, architectural
coating, furniture finishing, and cosmetic industries.
paint gun LVLP (Low Volume Low Pressure) paint spraying
Like HVLP, these spray guns also operate at a lower pressure (LP), but they
apply a low volume (LV) of coating (paint). This is a further effort at
increasing the transfer efficiency (amount of coating that ends up on the target
surface) of spray guns.
paint gun Electrostatic spray painting
In this method the target surface and the paint are electrically charged, one
with a negative and one a positive charge. This causes the coating to be
attracted to the target surface which increases the transfer efficiency. It is
best suited to coating conductive (metal) surface and is popular in the
automotive industries.
paint gun Rotational bell
Main article: Rotational bell painting
With this method the paint is flung into the air by a spinning metal disc
("bell"). The metal disc also imparts an electrical charge to the coating
particle.
paint gun Electric fan
There are a variety of hand-held paint sprayers that either combine the paint
with air, or convert the paint to tiny droplets and accelerate these out a
nozzle.
paint gun Air Assisted Airless spray guns
These use air pressure and fluid pressure (300 – 3000 psi) to achieve
atomization of the coating. This equipment provides high transfer and increase
application speed but is best used with flat line applications. Commonly found
in factory finish shops.
paint gun Airless spray guns
These operate connected to a high pressure pump commonly found using 300 – 7500
psi pressure to atomize the coating using different tip sizes to achieve desired
atomization and spray pattern size. This type of system is used by contract
painters to paint at a fast pace difficult thick coatings used in the
construction field or industrial environment.
paint gun Automated Linear Spray Systems
Manufacturers who mass produce wood products use a Automated Spray system, that
allows them to paint materials at a very high rate as well as at a minimum of
personnel. Automated Spray Systems usually incorporate a paint saving system,
this eliminates waste. Commonly, linear spray systems are when products are on
are laying flat on a conveyor belt and then enters into a linear spray system,
where automated spray guns are stationed above, and when the material is
directly below the guns, the guns then begin to paint the material. Materials
consist of window frames and any other material that is simple in design.
paint gun Automated Flatline Spray Systems
See also: Wood finishing
Mass produced material is loaded on a conveyor belt where it is fed into one of
these flatline machines. Flatline machines are designed to specifically to paint
material that is complex in shape. For example a kitchen cabinet. Spray guns are
aligned above the material and the guns are in motion in order to hit all the
grooves of the material. The guns are can be moving in a cycle or can be moving
back and forth in order to apply paint evenly across the material. Flatline
systems are typically large and can paint doors, kitchen cabinets, and other
plastic products.
paint gun Applications
One of the applications is graffiti. Spray-painting has also been used in fine
art (using airbrush type), for both painting and sculpture
paint gun
Airbrush
Primer (paint)
Spray paint art
Huffing paint spraying
paint gun More Spray Painting Resources
Spray Painting of Automobiles - Problems and Solutions
Plastikote - How to spray paint
How To Video - 3M Paint Preparation System Available in Spanish and English
Painting techniques Painting materials
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