MIL-HDBK-1110
b) Immerse the roller completely in the paint and
remove the excess by moving the roller back on the tray or grid.
Skidding or tracking may occur if the roller is loaded with too
much paint.
c) Apply the paint to the surface by placing the
roller against the surface forming a "V" or "W" of a size that
will define the boundaries of the area that can be covered with
the paint on a loaded roller. Then roll out the paint to fill in
the square area. Roll with a light touch and medium speed.
Avoid letting the roller spin at the end of a stroke. Always
work from a dry adjacent surface to a wet surface. The wet edge
should be prevented from drying to minimize lap marks.
d) Use a brush or foam applicator to apply paint in
corners, edges, and moldings before rolling paint on the adjacent
areas.
7.5.4
Spray Application. Spray application is the fastest
technique for applying paint to large areas. Spray application
also results in a smoother, more uniform surface than brushing or
rolling. There are several types of equipment: conventional
air, airless, air-assisted airless, high-volume, low-pressure
(HVLP), electrostatic, multi-component, thermal, and powder.
Conventional air and airless were most commonly used. However,
with changing VOC requirements the other methods are being used
more. Air or air-assisted methods of spraying, including HVLP,
rely on air for paint atomization. Jets of compressed air are
introduced into the stream of paint at the nozzle. The air jets
break the paint stream into tiny particles that are carried to
the surface on a current of air. The delivery of the paint to
the nozzle may be assisted using hydraulic pressure. In airless
spray, paint is forced through a very small nozzle opening at
very high pressure to break the exiting paint into tiny droplets.
A general comparison of properties of conventional air and
airless spray are given in Table 11. Note that specific
application rates, the amount of overspray, and other properties
depend to a great extent upon the type of paint, and may vary
from those listed in the table. Air methods other than
conventional have been developed to overcome some of the
environmental and other concerns of air and airless spray. These
differences are discussed separately for each method below.
7.5.4.1
Conventional or Air Spray Equipment. The conventional
method of spray application is based on air atomization of the
paint. The basic equipment (air compressor, paint tank, hoses
for air and paint, spray gun) is shown in Figure 10. The coating
material is placed in a closed tank (sometimes called a pot)
connected to the nozzle by a hose and put under regulated
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