Page 1
SERVICE BULLETIN
SB-2-253-I
Replaces SB-2-253-H
■Major Repair Kit KK-4987-2
Minor Repair Kit KK-5034
JGA-503 CONVENTIONAL SPRAY GUN
IMPORTANT: Before using this equipment, read all safety precautions and instructions. Keep for future use.
DESCRIPTION
The standard JGA-503 spray gun is a
general purpose, heavy duty, high production spray gun suitable for use with most
types of materials. The fluid passageway is
plated brass, aluminum and stainless steel.
The fluid tip and needle is stainless steel.
Halogenated hydrocarbon solvents
- for example; 1, 1, 1 - trichloroethane
and methylene chloride - can chemically react with the aluminum in
this gun and cause an explosion
hazard. Read the label or data sheet
for the material you intend to
spray. Do not use spray materials
containing these solvents with this
spray gun.
Important: This gun may be used with
most common coating and finishing materials. It is designed for use with mildly
corrosive and nonabrasive materials. If
used with other high corrosive or abrasive materials, it must be expected that
frequent and thorough cleaning will be
required and the necessity for replacement of parts will be increased.
INSTALLATION
1. Attach the air supply line to the air
inlet (24). An air transformer installed
as close as possible to the gun will
provide filtered and regulated air.
Note
When larger diameter air hoses
are used, it is advisable to use an
8' or 10' "whip end" or a smaller
diameter hose at the gun for
greater flexibility or movement.
2. Attach the suction feed cup or fluid
hose to the material inlet.
Note
Protective coating and rust inhibitors
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
manufacturer's instructions.
Strain material through a 60 or 90 mesh
screen.
1. Fill the suction or pressure feed cup
with the material. Do not overfill. Make
sure that the cup lid vent hole is clear,
if using a suction cup.
2. Turn on the gun air at the source of
supply. Adjust the atomization air pressure to 35 psi.
3. Turn on the supply air to the pressure
cup if used.
4. Open the spreader adjustment valve
(25) (Fan) by turning the valve stem
counter-clockwise.
5. Open the fluid needle adjusting screw
(28) by turning counter-clockwise.
6. Spray a test area.
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 material
flowing for the atomization air pressure
being used.
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 the spreader
adjustment valve (25), either clockwise to
decrease the width or counter-clockwise
to increase the width.
See Spray Gun Guide SB-2-001 (latest
revision) for details concerning set up of
spray guns.
■Government NSN No. 4940-01-046-9919 = KK-4987-2
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. Never use a wire or hard in-
strument. This may scratch or burr holes
causing a distorted spray pattern.
To clean fluid passages, remove excess
material at source, then flush with a suitable solvent using a device such as the
SolventSaver™ (see Accessories). 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
time. Using worn parts can cause
fluid leakage. Matched or lapped
sets are available for most pressure
feed combinations. See Chart 3.
Sets are particularly recommended
with thinner, less viscous materials.
Also, replace the needle packing at
this time. Lightly lubricate the
threads of the fluid tip before reassembling. Torque to 15-20 ft. lbs.
Do not overtighten the fluid tip.
To prevent damage to the fluid tip
(4) or fluid needle (4), be sure to
either 1) pull the trigger and hold
while tightening or loosening the
fluid tip or 2) remove fluid needle
adjusting screw (28) to relieve
spring pressure against needle
collar.
both at the same
Page 2
Page 2 SB-2-253-I
SAFETY PRECAUTIONS
This manual contains information that is improtant for you to know and understand. This information relates to USER SAFETY
and PREVENTING EQUIPMENT PROBLEMS. To help you recognize this information, we use the following symbols.
Please pay particular attention to these sections.
Note
Important safety information - A hazard
that may cause serious injury or loss
of life.
The following hazards may occur during the normal use of this equipment.
Please read the following chart before using this equipment.
HAZARD CAUSE SAFEGUARDS
Fire
Solvent
Spray
Inhaling Toxic
Substances
Explosion Hazard Incompatible
Materials
General Safety
Cumulative Trauma
Disorders (“CTD’s”)
CTD’s, or musculo- CTD's when using hand tools, tend to affect any such symptoms, see a physician immediately. Other early
skeletal disorders, the upper extremities. Factors which may symptoms may include vague discomfort in the hand, loss of
involve damage to increase therisk of developing a CTD include: manual dexterity, and nonspecific pain in the arm. Ignoring early
the hands, wrist, symptoms and continued repetitive use of the arm, wrist and
elbows, shoulders, 1. High frequency of the activity. hand can lead to serious disability. Risk is reduced by avoiding
neck and back. Carpal 2. Excessive force, such as gripping, pinching, or lessening factors 1-7.
tunnel syndrome and or pressing with the hands and fingers.
tendinitis (such as 3. Extreme or awkward finger, wrist, or arm
tennis elbow or positions.
rotator cuff 4. Excessive duration of the activity.
syndrome) are 5. Tool vibration.
examples of CTD’s. 6. Repeated pressure on a body part.
Solvent and coatings can be highly flammable Adequate exhaust must be provided to keep air free of
or combustible especially when sprayed. accumulations of flammable vapors.
During use and while cleaning and flushing, Wear eye protection.
solvents can be forcefully expelled from fluid
and air passages. Some solvents can cause
eye injury.
Certain materials may be harmful if inhaled, or Follow the requirements of the Material Safety Data Sheet
if there is contact with the skin. supplied by your coating material manufacturer.
Halogenated hydrocarbon solvents - for Guns with stainless steel internal passageways may be used
example; methylene chloride and 1, 1, 1 - with these solvents. However, aluminum is widely used in other
Trichloroethane are not chemically compatible spray application equipment - such as material pumps, regulawith the aluminum that might be used in many tors, valves and cups. Check all equipment items before use and
system components. The chemical reaction make sure they can also be used safely with these solvents. Read
caused by these solvents reacting with the label or data sheet for the material you intend to spray. If in
aluminum can become violent and lead to doubt as to whether or not a coating or cleaning material is
an equipment explosion. compatible, contact your material supplier.
Improper operation or maintenance of Operators should be given adequate training in the safe use and
equipment. maintenance of the equipment (in accordance with the require-
Use of hand tools may cause cumulative Pain, tingling, or numbness in the shoulder, forearm, wrist,
trauma disorders (“CTD’s”). hands or fingers, especially during the night, may be early
7. Working in cold temperatures.
CTD’s can also be caused by such activities
as sewing, golf, tennis bowling, to name a few.
Important information that tells how
to prevent damage to equipment, or
how to avoid a situation that may
cause minor inury.
Smoking must never be allowed in the spray area.
Fire extinguishing equipment must be present in the spray area.
Adequate exhaust must be provided to keep the air free of
accumulations of toxic materials.
Use a mask or respirator whenever there is a chanced of inhaling
sprayed materials. The mask must be compatible with the
material being sprayed and its concentration. Equipment must be
as prescribed by an industrial hygienist or safety expert, and be
NIOSH approved.
ments of NFPA-33, Chapter 15). Users must comply with all local
and national codes of practice and insurance company require
ments governing ventilation, fire precautions, operation, maintenance and housekeeping. These are OSHA Sections 1910.94
and 1910.107 and NFPA-33.
symptoms of a CTD. Do not ignore them. Should you experience
Information that you should pay special
attention to.
Page 3
SB-2-253-I Page 3
SPRAY GUN LUBRICATION
Daily, apply a drop of *SSL-10 gun lube at
trigger bearing stud (21) and the stem of
the air valve (13) where it enters the air
valve assembly (17). The shank of the fluid
needle (4) where it enters the packing nut
(19) should also be oiled. The fluid needle
packing (18) should be lubricated periodically. Make sure the baffle (6) and retaining
ring (2) threads are clean and free of foreign
matter. Before assembling retaining ring to
baffle, clean the threads thoroughly, then
add two drops of SSL-10 spray gun lube to
threads. The fluid needle spring (30) and air
valve spring (12) should be coated with a
very light grease, making sure that any
excess grease will not clog the air passages. For best results, lubricate the points
indicated daily with SSL-10 spray gun lube.
A. Trigger Points
B. Packing
C. Adjusting Valves
D. Baffle Threads
E. Air Valve Cartridge
* Not for air tools or high RPM equipment.
"Material Safety Data Sheet" available from
DeVilbiss upon request.
D
B
E
A
C
PARTS LIST
Ref. Replacement Individual
No. Part No. Description Parts Required
1 See Chart 2 Air Cap/Retaining Ring ............................................1
2 MBC-368 Air Cap Retaining Ring ............................................ 1
3 JGA-156-K10 Spring Clip . .............................................................. 1
4 See Chart 3 Fluid Tip and Needle . ............................................. 1
* 5 JGD-14-K10 Gasket Kit (Kit of 10) . .............................................. 1
(Polyethylene)
6 JGD-402-1 Baffle and Gasket Kit . ............................................. 1
7 --- Fluid Inlet Gasket (PTFE) ......................................... 1
8 --- Lock Nut .................................................................... 1
9 --- Fluid Inlet Nipple . .................................................... 1
10 JGA-4042 Fluid Inlet and Nut Kit ..............................................1
•*11 JGS-72-K10 Gasket Kit (Kit of 10) (PTFE ) ................................... 2
*12 --- Spring ....................................................................... 1
*13 --- Air Valve ................................................................... 1
•*14 --- U Cup Seal ................................................................ 1
*15 --- Washer ...................................................................... 1
*16 --- Snap Ring . ............................................................... 1
17 JGS-449-1 Air Valve Assembly ................................................. 1
•*18 JGV-463-K3 Packing Kit (Kit of 3) . .............................................. 1
19 34411-122-K10 Packing Nut Kit (Kit of 10) . .....................................1
*20 --- Screw ........................................................................ 1
21 JGS-478 Stud and Screw Kit (Kit . ......................................... 1
(includes 3 studs and 5 screws)
22 JGS-477-1 Trigger, Stud and Screw Kit
(Kit includes 1 each) .............................................. 1
23 JGA-132 Plug ........................................................................... 1
24 P-MB-51 Air Inlet Connector 1/4" NPS(M) . ...........................1
25 JGA-497-1 Spreader Adjustment Assembly ............................ 1
*26 --- Retaining Ring .......................................................... 1
•*27 --- O-Ring (Viton) .......................................................... 1
28 JGS-16 Adjusting Screw .......................................................1
*29 --- Spring Pad (Included with # 30 and 32) . .............. 1
*30 MBD-19-K10 Spring Kit (Kit of 10) . .............................................. 1
31 --- Bushing ..................................................................... 1
32 JGA-4041 Bushing, Spring, Pad and Knob Kit ........................ 1
33 --- Gun Body .................................................................. 1
CHART 1
NOZZLE COMBINATIONS
Air Cap
Sizes
Order
From
Chart 2
Tip
Orifice
in./ .070 .063 .055 .042
mm 1.8 1.6 1.4 1.1
Fluid Tip and Needle Sizes
Order From Chart 3
EX FW FF FX
80 S S
777 P
9000 S S P
S = Suction Feed Combination
P = Pressure Feed Combination
CHART 2
AIR CAPS
No. on Ref. No. (1)
Cap Air Cap
♦
Order With Ring
80 MB-4039-80
777 AV-440-777
9000 AV-440-9000
* A quantity of necessary parts is included in repair kit ■ KK-4987-2 for complete gun
repair and should be kept on hand for service convenience.
• A quantity of necessary parts is included in Minor Repair Kit KK-5034 for gun repair.
Suffixes - K10 designates kits of multiple parts. (Example) JGD-14-K10 is a kit of 10
gaskets.
■Government NSN No. 4940-01-046-9919 = KK-4987-2
CHART 3
FLUID TIPS AND NEEDLES
If this is No. Ref. No. 4
on Tip Tip & Needle Sets
Order
STAINLESS STEEL TIPS AND NEEDLES
AV-2115-EX JGA-4040-EX (matched set)
AV-2115-FF JGA-4040-FF (lapped set)
AV-2115-FW JGA-4040-FW (matched set)
AV-2115-FX JGA-4040-FX (lapped set)
AV-1 copper gasket is included with all fluid
tip and needle sets, but is not required and
should not be used on this spray gun.
Page 4
Page 4 SB-2-253-I
25
Spreader Adjustment
Assembly
27
32
30
31
29
28
11
26
4
1
Or
Torque to
15-20 ft. lbs.
6
5
33
1
4
3
Air Inlet Nipple
* 24
2
1/4 NPS (M)
(Torque to 15 ft. lbs.)
23
7
8
10
9
Fluid Inlet Nipple
3/8 NPS (M)
∆
*
Torque to
20-25 ft. lbs.
18
12
19
11
21
20
Detail Ref. No. 18 - Two piece packing
∆
covered by U.S.Patent No. 5,209, 501.
+ Tapered edge faces out towards
packing nut.
+Inner PTFE Piece
Fluid Packing Nut
13
14
16
15
17
*Apply thread sealant (i.e. Loctite #242 med.
strength blue or equal) onto threads.
Outer
U.H.M.W.
Poly. Piece
Fluid Needle
22
• Orient packing components as shown.
• Tighten packing nut until needle starts to
drag in packing. Then loosen packing
nut just enough so the needle moves
freely.
WARRANTY
This product is covered by DeVilbiss' 1 Year
Limited Warranty. See SB-1-000 which is available
upon request.
Page 5
TROUBLESHOOTING
CONDITION CAUSE CORRECTION
SB-2-253-I Page 5
Heavy top or
bottom pattern
Heavy right or
left side pattern
Heavy center pattern
Split spray pattern
Jerky or fluttering spray
Horn holes plugged. Clean. Ream with nonmetallic point.
Obstruction on top or bottom of fluid tip. Clean.
Cap and/or tip seat dirty. Clean.
Left or right side horn holes plugged. Clean. Ream with nonmetallic point.
Dirt on left or right side of fluid tip. Clean.
Remedies for the top-heavy, bottom-heavy, right-heavy and left-heavy patterns:
1) Determine if the obstruction is on the air cap or the fluid tip. Do this by making a test spray
pattern. Then, rotate the cap one-half turn and spray another pattern. If the defect is inverted,
obstruction is on the air cap. Clean the air cap as previously instructed.
2) If the defect is not inverted, it is on the fluid tip. Check for a fine burr on the edge of the fluid tip.
Remove with #600 wet or dry sand paper.
3) Check for dried paint just inside the opening. Remove paint by washing with solvent.
Fluid pressure too high for atomization Balance air and fluid pressure.
air (pressure feed). Increase spray pattern width with spreader
adjustment valve.
Material flow exceeds air cap's capacity. Thin or lower fluid flow.
Spreader adjustment valve set too low. Adjust.
Atomizing pressure too low. Increase pressure.
Material too thick. Thin to proper consistency.
Atomization air pressure too high. Reduce at transformer or gun.
Fluid pressure too low (pressure feed only). Increase fluid pressure (increases gun
handling speed).
Spreader adjusting valve set too high. Adjust.
*Loose or damaged fluid tip/seat. Tighten or replace.
Material level too low. Refill.
Container tipped too far. Hold more upright.
Obstruction in fluid passage. Backflush with solvent.
Loose or broken fluid tube or fluid inlet nipple. Tighten or replace.
Dry or loose fluid needle packing nut. Lubricate or tighten.
Unable to get round spray
Will not spray
Starved spray pattern
Excessive overspray
Excessive fog
Dry Spray
Fluid leaking from
packing nut
Paint bubbles in cup.
Spreader adjustment screw not seating properly. Clean or replace.
Air cap retaining ring loose. Tighten.
No air pressure at gun. Check air supply and air lines.
Internal mix or pressure feed air cap and tip Change to proper suction feed air cap and tip.
used with suction feed.
Fluid pressure too low with internal mix cap and Increase fluid pressure at tank.
pressure tank.
Fluid needle adjusting screw not open enough. Open fluid needle adjusting screw.
Fluid too heavy for suction feed. Thin material or change to pressure feed.
Inadequate material flow. Back fluid adjusting screw out to first thread
or increase fluid pressure at tank.
Low atomization air pressure (suction feed) Increase air pressure and rebalance gun.
Too much atomization air pressure. Reduce pressure.
Gun too far from work surface. Adjust to proper distance.
Improper stroking (arcing, gun motion too fast). Move at moderate pace, parallel to work surface.
Too much, or too fast-drying thinner. Remix properly.
Too much atomization air pressure. Reduce pressure.
Air pressure too high. Reduce air pressure.
Gun tip too far from work surface. Adjust to proper distance.
Gun motion too fast. Slow down.
Gun out of adjustment. Adjust.
Packing nut loose. Tighten, do not bind needle.
Packing worn or dry. Replace or lubricate.
Fluid tip not tight. Tighten tip to 20-25 ft. lbs.
*Most common problem.
Page 6
Page 6 SB-2-253-I
Troubleshooting (continued)
CONDITION CAUSE CORRECTION
Fluid leaking or dripping
from front of gun
Runs and sags
Thin, sandy coarse finish
drying before it flows out
Thick, dimpled finish
"orange peel".
ACCESSORIES
WR-103
Wrench
42884-214-K5
42884-215-K10
Cleaning Brushes
3/8"
5/8"
Packing nut too tight. Adjust.
Dry packing. Lubricate.
Fluid tip or needle worn or damaged. Replace tip and needle with lapped sets.
Foreign matter in tip. Clean.
Fluid needle spring broken. Replace.
Wrong size needle or tip. Replace.
Too much material flow. Adjust gun or reduce fluid pressure.
Material too thin. Mix properly or apply light coats.
Gun tilted on an angle, or gun motion Hold gun at right angle to work and adapt to
too slow. proper gun technique.
Gun too far from surface. Check distance. Normally approx. 6-8".
Too much air pressure. Reduce air pressure and check spray pattern.
Improper thinner being used. Follow paint manufacturer'smixing instructions.
Gun too close to surface. Check distance. Normally approx. 6-8".
Too much material coarsely atomized. Air pressure too low.
Increase air pressure or reduce fluid pressure.
Improper thinner being used. Follow paint manufacturer'smixing instructions.
Material not properly mixed. Follow paint manufacturer'smixing instructions.
Surface rough, oily, dirty. Properly clean and prepare.
HARG-510
Air Regulator
HAV-500 OR
HAV-501
Adjusting
Valve
(HAV-501 SHOWN)
MSP-524 Twin
Cartridge,
Paint Spray
Respirator
Spray Gun Lube
SSL-10
192212 Professional
Spray Gun Cleaning Kit
Compatible with all
paint materials: contains no silicone or
petroleum distillates to contaminate
paint. MSDS available upon request.
Contains six precision tools
designed to effectively clean
all DeVilbiss, Binks, Finishline
and other brand spray guns.
Automotive Quick Connects For HVLP
Guns (Air) High Flow Type.
HC-4719
Coupler
HC-4419 Stem
1/4" NPT(F)
HC-1166 Stem
1/4" NPT(M)
1/4" NPT(M) /
NPS(M)
HC-4720
Coupler
1/4" NPT(F)
Contains all necessary tip, hose and
nut sizes used on or
with gun.
192218 Scrubs
Hand Cleaner
Towels
Premoistened
waterless hand
cleaner towels for
painters, body men
and mechanics.
These brushes are
helpful in cleaning
threads and recesses of gun body.
®
JGA-156-K10
Spring Clip
Joins any single
piece DeVilbiss air
cap with latest version MBC-368 or
MSA-1 retaining ring.
Helps prevent parts
loss and provides
easier assembly.
Use to maintain
nearly constant outlet pressure despite
changes in inlet
pressure and downstream flow.
TGC-545 (Alum.)
TLC-555 (PTFE
Lined), 2 Qt. Drip
Free Suction Cup
Cup has a unique,
two position valve
which permits selection of either a dripfree or conventional
open vent mode.
HAV-500 does not
have pressure
gauge. Use to control air usage at gun.
JGA-4005 Air
Adjusting Valve
Installs into gun to
enable user to control and reduce air
usage at the gun.
Replaces JGA-132
plug.
NIOSH-Certified
(TC-84A-1623 for
respiratory protection in atmospheres
not immediately
dangerous to life.
HAF-507
Whirlwind™
In-Line Air Filter
Removes water, oil,
and debris from the
air line.
DeVILBISS WORLDWIDE SALES AND SERVICE LISTING - www.devilbiss.com
AUTOMOTIVE REFINISHING
DeVilbiss has authorized distributors throughout the world. For equipment, parts and service, check the Yellow Pages
under "Automobile Body Shop Equipment and Supplies". FOR TECHNICAL ASSISTANCE, CALL TOLL FREE
1-800-445-3988 (U.S.A. ONLY). FOR LOCAL CALLS, SEE LISTING BELOW.
U.S. Customer Service Office Address Telephone No.
MAUMEE, OH 43537 1724 Indian Wood Circle (419) 891-8100
8/02 ©Copyright 2002, DeVilbiss, Automotive Refinishing Printed in U.S.A.
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