DeVilbiss GFG-670 PLUS Service Bulletin

GFG-670 PLUS
IMPORTANT: Before using this equipment,
read all safety precautions and instructions.
Keep for future use.
DESCRIPTION
The standard Plus spray gun is a general
®
purpose, heavy-duty, high production
gravity spray gun suitable for use with most
types of materials.
NOTE
This gun includes 300 series stain-
less steel fluid tip and needle. The
fluid passageway is plated alumi-
num. Guns may be used with chlori -
nated solvent materials only if the
attached gravity cup is Acetal or
Nylon. Do not use aluminum cups
with chlorinated solvent materials.
Important: This gun may be used with most
common coating and finishing materials.
It is designed for use with mildly corrosive
and non-abrasive materials. If used with
other high corrosive or abrasive materi-
als, it must be expected that frequent and
thorough cleaning will be required and the
necessity for replacement of parts will be
increased.
INSTALLATION
For maximum transfer efficiency, do not use
more pressure than is necessary to atomize
the material being applied.
1. Connect the gun to a clean, moisture and
oil free air supply using a hose size of
at least 5/16" I.D. hose. Do not use 1/4"
I.D. hose (25' x 1/4" hose at 18 CFM has a
pressure loss of 25 psi. 25' x 5/16" hose
at 18 CFM has a pressure loss of 8 psi).
NOTE
Depending on hose length, larger
I.D. hose may be required. Do not
use more pressure than is neces-
sary to atomize the material being
applied. Excess pressure will create
additional overspray and reduce
transfer efficiency.
HIGH EFFICIENCY GRAVITY FEED SPRAY GUN
®
If an air adjusting valve is used at the
gun inlet, use DeVilbiss Model HAV-
500 or HAV-511. Some competitive
adjusting valves have significant
pressure drop that can adversely
affect spray performance. Models
HAV-500 and HAV-511 have minimal
pressure drop.
2. Attach the gravity feed cup to the
material inlet.
Protective coating and rust inhibi-
tors have been used to keep the
gun in good condition prior to
shipment. Before using the gun,
flush it with solvents so that these
materials will be removed from
fluid passages.
OPERATION
Mix, prepare and strain the material to be
sprayed according to the paint maufac-
turer's instructions.
Strain material through a 60 or 90 mesh
screen.
1. Fill the gravity feed cup with the mate-
rial. Do not overfill. Make sure that the
cup lid vent hole is clear.
2. Open the spreader adjustment valve
(10) (Fan) by turning the valve stem
counterclockwise.
3. Close the fluid needle adjusting screw
(17) by turning clockwise.
4. Turn on air supply. See Chart 1
for recommended inlet pressure.
Some materials can be sprayed at
lower pressures, improving transfer
efficiency.
5. Spray a test area by turning fluid needle
adjusting screw (17) counterclockwise
until a full coat is obtained.
If the finish is too sandy and dry, the material
flow may be too low for the atomization air
pressure being used.
If the finish sags, there is too much mate-
rial flowing for the atomization air pressure
being used.
NOTE
NOTE
SERVICE BULLETIN
SB-2-194-K
Replaces SB-2-194-J
Repair Kit KK-5058-2
Both of the above can be corrected by
increasing or decreasing the atomization
air pressure or the material flow. Pattern
width can be altered by turning spreader
adjustment valve (10), either clockwise to
decrease the width or counterclockwise to
increase the width.
See Spray Gun Guide, SB-2-001 latest
revision, for details concerning setup of
spray guns.
PREVENTIVE MAINTENANCE
To clean air cap and fluid tip, brush exterior
with a stiff bristle brush. If necessary to clean
cap holes, use a broom straw or toothpick
if possible. If a wire or hard instrument is
used, extreme care must be used to prevent
scratching or burring of the holes which will
cause a distorted spray pattern.
To clean fluid passages, remove excess
material from cup, then flush with a suit-
able solvent. Wipe gun exterior with a
solvent dampened cloth. Never completely
immerse in solvent as this is detrimental to
the lubricants and packings.
NOTE
When replacing the fluid tip or
fluid needle, replace both at the
same time. Using worn parts can
cause fluid leakage. See Chart 3.
Also, replace the needle packing
at this time. Lightly lubricate the
threads of the fluid tip before reas-
sembling. Torque to 15-20 ft. lbs.
Do not overtighten the fluid tip.
To prevent damage to fluid tip (5)
or fluid needle (11), be sure to either
1) pull the trigger and hold while
tightening or loosening the fluid
tip, or 2) remove fluid needle ad-
justing screw (17) to relieve spring
pressure against needle collar.
TRANSFER EFFICIENCY
The DeVilbiss GFG-670 (110264) PLUS
Gravity feed spray gun, when tested
under recommended conditions with
automotive refinishing materials, has been
found to exceed 65% transfer efficiency.
®