Husky HDS Serie Mode D'emploi page 2

Operating Instructions
General Safety
Information (cont.)
TOOL USE AND CARE
• Do not use pressure that
exceeds operating pressure
of the spray gun or any of
the parts (hoses, fittings,
etc.) in the painting system.
• Over pressurizing the spray gun is able
to result in bursting, abnormal opera-
tion, breakage of the spray gun or
serious injury to persons.
• Always verify prior to using the spray
gun that the air source has been
adjusted to the rated air pressure or
within the rated air-pressure range.
• Check for misalignment or binding of
moving parts, breakage of parts, and
any other condition that affects the
spray gun's operation. If damaged, have
the spray gun serviced before using.
Many accidents are caused by poorly
maintained spray guns. There is a risk of
bursting if the spray gun is damaged.
• Avoid unintentional starting. Be sure
the trigger is off before connecting to
the air supply. Do not carry the spray
gun with your finger on the trigger or
connect the spray gun to the air sup-
ply with the trigger on.
• Disconnect the spray gun from the
air source before, changing acces-
sories, cleaning, servicing or storing
the spray gun. Such preventive safety
measures reduce the risk of starting
the spray gun unintentionally.
• Failure to install appropriate water/oil
removal equipment may result in dam-
age to machinery or workpiece.
• Always use a pressure regulator on
the air supply to the spray gun.
Introduction
The spray gun is a vital link in any finishing
application. In addition to operating the
spray gun properly, techniques of surface
preparation and paint preparation must be
understood. These instructions will explain
the differences among various spray
technologies and serve as a guide in the
proper operation and techniques of spray
painting. Refer to the Replacement Parts
Manual for model specific information.
Currently, there are three basic types
of spray guns: Siphon, Pressure, and
Gravity feed (See Figures 2-5). The spray
gun type used depends primarily on the
application and the size of the project.
These types of spray guns can be either
conventional air spray or High Volume
Low Pressure (HVLP).
SPRAY GUN TERMS
FEED – Method used to bring paint
into the gun for spraying.
PRESSURE FEED – Method of paint
feed where a canister or paint tank is
pressurized to force paint to the gun.
Either internal or external mix air caps
are used with this method. Pressure feed
is generally used for spraying heavy bod-
ied paints or for large size projects.
SIPHON FEED – Method of paint feed
where atmospheric pressure creates a
partial vacuum to siphon paint to the
gun. Only external mix air caps are used
with this method. Siphon feed is used
with light bodied paints.
GRAVITY FEED – Method of paint
feed similar to the siphon feed method.
However, the cup is inverted to create a
positive fluid pressure at the nozzle.
MIX – The mixing of paint and air
when spraying.
INTERNAL MIX – Process where the air
and paint are mixed inside the air cap
just before being sprayed. This method is
best for heavy bodied, slow drying paints
and can only be used with the pressure
feed method. Do not use fast drying
paints with internal mix. The paint will
dry inside and quickly clog the air cap.
EXTERNAL MIX – Process where the air
and paint are mixed just after leaving
the nozzle. This type of mix should be
used for fast drying paints and when a
high quality finish is needed.
BLEEDER/NON-BLEEDER – Indicates
whether air flows through the gun con-
tinuously or as the trigger is pulled.
BLEEDER – In this mode, air passes
continuously through the gun whether
spraying or not. This mode is generally
used when the air is supplied by a con-
tinuously running compressor that does
not have a tank.
2
HDS Model Series
NON-BLEEDER – In this mode, air flows
only when the trigger is pulled. This
type of operation is used with a com-
pressor equipped with a tank or with a
large factory air system.
VISCOSITY – A measurement of the
resistance of the flow of a liquid.
ATOMIZATION - Conversion of liquid
to spray droplets (mist).
PATTERN CONTROL KNOB – Used
to form the proper pattern (size and
shape) of paint as it is sprayed from the
gun to the work piece.
FLUID CONTROL KNOB – Used to con-
trol the amount of paint being mixed
with air.
PAINT TANK – An auxiliary pressurized
paint reservoir that allows continuous
spraying of large amounts of paint with-
out stopping for refills as with a canister.
It also allows using the spray gun at any
angle or orientation.
CONVENTIONAL VS. HVLP
Conventional spray guns use a much
higher air cap pressure to atomize paint
than HVLP spray guns. This results in more
overspray and a lower transfer efficiency.
HVLP, electrostatic and airless processes are
currently the only compliant spray meth-
ods that meet the strict 65% transfer effi-
ciency criteria required by some air quality
management districts. This enhanced
transfer efficiency results in a significant
material savings compared to conventional
spraying. Check local, state and national
regulations that may be in effect before
performing any spraying operations.
HVLP spraying is a growing trend in the
finishing industry due to its environmen-
tal friendliness. By definition, dynamic
air pressures in the air cap must be 10
psi or less to qualify as HVLP. A soft, low
velocity pattern is
Conventional
produced which
increases con-
trol and reduces
"bounceback"
and overspray (See
HVLP
Figure 1). For these
reasons, HVLP is
also well suited for
spraying parts with
Figure 1
recessed areas.