Table 1-4.--Proper Cleaners for Paintbrushes
MATERIALS USED
CLEANERS
Natural and synthetic oil-based paints and
Paint thinners or mineral spirits
varnishes
Latex emulsion
Water
Shellac
Alcohol
Lacquer
Lacquer thinner
add only a recommended thinner. Never add diesel oil,
Pigment
varnish, or other nonrecommended material.
Pigment is used to give color to the paint. Some
Driers
pigments also increase the quality of the paint. Inert
pigments are chemically stable and do not affect color
When mixed with oil, certain metallic compounds
or destroy the life of the paint vehicle. They are used to
add to the drying properties of the paint. They are
provide a less-expensive base for certain kinds of paint
driers and, as used in the Navy, consist chiefly of
colors, to decrease the amount of active pigment in the
compounds of cobalt naphthenates.
paint, and to help prevent settling and caking of the
A paint drier acts as a conveyor of oxygen. It takes
pigment in the container. Some common inert
the oxygen from the air and adds it to the oil. This
pigments presently in use are barium sulfate, calcium
process speeds the oxidation of the paint. Without the
carbonate, whiting, magnesium silicate, talc, and
drier, absorption of oxygen would be too slow, and it
silica.
would take too long for the paint to dry.
Vehicle
Thinners
The vehicle, usually referred to as the base, is the
Thinners reduce the consistency of paint to the
liquid portion of the paint that acts as the binder and the
proper degree for application by spraying, brushing, or
brushing medium for the pigment particles. The base
rolling. Thinners also increase the penetration of paint
wets the surface to be painted, penetrates into the
into the surface being painted, and they cut down on
pores, and ensures proper adhesion of the film formed
gloss. Too much thinner, however, dilutes the vehicle
by the drying vehicle.
too much. As mentioned earlier, the vehicle is a binder;
if it is diluted excessively, the durability of the paint is
Until recently, the base of most paints was an oil,
affected. In flat paints, the proportion of the oil is
such as linseed oil. Today, only a few Navy paints
deliberately reduced by thinners to cause the paint to
contain raw oil. The base of some Navy paints is
dry without gloss.
processed oil in combination with a synthetic resin.
Other paints have a vinyl base and some have a water
PAINT PREPARATION
base.
Most oil-based vehicles dry partially by
No matter how high the quality of the paint, it will
give poor service if it is not thoroughly mixed before it
evaporation, partially by oxidation, and partially by
is applied. When paint stands for a long period of time,
polymerization. Polymerization is the process where
the pigment settles to the bottom of the container and
two or more similar molecules combine chemically to
the vehicle rises to the top. Subsequently, the paint
form a larger molecule of a new substance. Older
must be remixed before use.
paints contained raw oils, had poor physical properties
when dry, and dried slower than modern paints. For
If you do not have a mechanical mixer, the best
these reasons, raw oils should NEVER be added to a
system for mixing is to pour off most of the vehicle into
Navy paint. If the paint is thick and needs to be thinned,
an empty can and mix the remainder thoroughly. Then
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