Graco Optimiser 2K 02748 User manual

308–341
Rev. G
Supersedes F
First choice when
quality counts. 
02748
INSTRUCTIONS-PARTS LIST
INSTRUCTIONS
This manual contains important
warnings and information.
READ AND KEEP FOR REFERENCE.
Optimiser 2K 
HVLP T wo Component
Adhesive Spray Gun
100 psi (7 bar) Maximum Working Fluid and Air Pressure
This gun is for use with water-based contact adhesives only
Part No. 949–239, Series C
U.S. Patent Pending
GRACO INC. P.O. BOX 1441 MINNEAPOLIS, MN 55440–1441
COPYRIGHT 1993, GRACO INC.
Graco Inc. is registered to I.S. EN ISO 9001

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Table of Contents
Warnings 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Selection Chart 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air Flow and Atomizing Pressure 5. . . . . . . . . . . . . . . . .
Installation 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setup and Shutdown 7. . . . . . . . . . . . . . . . . . . . . . . . . . .
Ratio Check 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Daily Gun Care, Flushing, and Cleaning 14. . . . . . . . . .
Troubleshooting 17 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service 18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts 24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Technical Data 26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dimensions 26 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Graco Phone Number Back Cover . . . . . . . . . . . . . . . . . .
Warranty Back Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Symbols
Warning Symbol
WARNING
This symbol alerts you to the possibility of serious
injury or death if you do not follow the instructions.
Caution Symbol
CAUTION
This symbol alerts you to the possibility of damage to
or destruction of equipment if you do not follow the
instructions.
WARNING
INSTRUCTIONS
EQUIPMENT MISUSE HAZARD
Equipment misuse can cause the equipment to rupture, malfunction or start unexpectedly and result in
serious injury .

This equipment is for professional use only .

Read all instruction manuals, tags, and labels before operating the equipment.
 Use the equipment only for its intended purpose. If you are uncertain about usage, call your Graco
distributor.

Do not alter or modify this equipment. Use only genuine Graco parts and accessories.
 Check equipment daily . Repair or replace worn or damaged parts immediately .

Use this equipment only in low pressure, air spray systems.
 Do not exceed the maximum working pressure of the lowest rated system component. This equip -
ment has a 100 psi (7 bar) maximum working fluid and air pressure .

Do not lift pressurized equipment.
 Use fluids or solvents that are compatible with equipment wetted parts. See the T echnical Data
section of all equipment manuals. Read the fluid and solvent manufacturer ’ s warnings.
 Comply with all applicable local, state and national fire, electrical and other safety regulations.

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WARNING
PRESSURIZED EQUIPMENT HAZARD
Spray from the gun, hose leaks or ruptured components can splash fluid in the eyes or on the skin and
cause serious injury .

Do not stop or deflect fluid leaks with your hand, body , glove or rag.
 Follow the Pressure Relief Procedure on page 7 when: you are instructed to relieve pressure;
stop spraying; clean, check or servicing the equipment; and install or clean fluid nozzles.
 Never point the spray gun at anyone or at any part of the body .

Never put hand or fingers over the spray nozzle.
T ighten all fluid connections before operating the equipment.
 Check the hoses, tubes and couplings daily . Replace worn, damaged or loose parts immediately .
Permanently coupled hoses cannot be repaired; replace the entire hose.
 Route hoses away from traf fic areas, sharp edges, moving parts and hot surfaces.
 Do not use the hoses to pull equipment.
FIRE AND EXPLOSION HAZARD
Poor air ventilation, open flames or sparks can cause a hazardous condition and result in fire or explo -
sion and serious injury .

Provide fresh air ventilation to avoid the buildup of flammable fumes from solvent or the fluid being
sprayed.

Extinguish all open flames or pilot lights in the spray area.
 Electrically disconnect all equipment in the spray area.
 Keep the spray area free of debris, including solvent, rags and gasoline.
 Do not turn on or of f any light switch in the spray area while operating or if fumes are present.
 Do not smoke in the spray area.
 Do not operate a gasoline engine in the spray area.
TOXIC FLUID HAZARD
Hazardous fluids or toxic fumes can cause serious injury or death if splashed in the eyes or on the
skin, inhaled, or swallowed.
 Know the specific hazards of the fluid you are using. Read the fluid manufacturer ’ s warnings.
 Store hazardous fluid in an approved container . Dispose of hazardous fluid according to all local,
state and national guidelines.
 Dress appropriately for your application. W ear protective eyewear , noise protection for the ears, a
personal respirator , gloves and clothing.

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Selection Chart
Includes:
Needle/
Nozzle/Air
Cap
Kit
P/N
Needle
Assembly
P/N
Air Cap
P/N Nozzle
P/N
Replacement
Needle T ip
P/N
Orifice Size
949–276 238–703 185–794 185–756 191–564 0.020” (0.508 mm)
949–277 238–703 185–794 185–757 191–564 0.026” (0.660 mm)
949–278 238–703 185–794 185–700 191–564 0.030” (0.762 mm)
949–279 238–217 185–794 185–701 191–016 0.042” (1.067 mm)
949–280 238–218 185–794 185–702 191–017 0.055” (1.397 mm)
949–281 238–219 185–795 185–703 191–018 0.070” (1.778 mm)
949–282 238–220 185–796 185–704 191–019 0.086” (2.184 mm)
Selecting a Needle/Nozzle/Air Cap Kit
The kits range in size to provide different fluid flow
rates.

Use the fluid nozzle that will give the required flow
with the fluid adjustment knob opened four full turns
counterclockwise and an adhesive pressure of
approximately 5 to 20 psi (0.35 to 1.4 bar).
 For low flow rates or light viscosity fluid, select the
smaller nozzle sizes.
 For high flow rates or high viscosity fluid, select the
larger nozzle sizes.
 Using an air cap size that is smaller than the
nozzle/needle size is not recommended.
T o help select the proper needle/nozzle size, a fluid
pressure gauge may be connected temporarily to
the gun fluid inlet to determine the fluid pressure.
 See Service to install the parts.
Selection Problems and Solutions
PROBLEM POSSIBLE
CAUSE SOLUTION
Fluid pressure
required to achieve
flow rate is too high
Using set with
too small of an
orifice
Use needle/
nozzle/air cap
set with larger
orifice
Using a low pres -
sure setting, the
fluid flow is too high,
making it necessary
to restrict needle
travel to reduce fluid
flow
Using set with
too large of an
orifice
Use needle/
nozzle/air cap
set with small -
er orifice
Fluid system will not
operate at low
enough fluid pres -
sure
Fluid regulator is
not installed or
air regulator is
not sensitive
enough
Add low pres -
sure fluid regu -
lator or add
more sensitive
air regulator on
pressure pot

308-3415
Air Flow and Atomizing Pressure
NOTE: All tests completed with the fan air fully open.
Air Flow
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
15 25 35 45 55 65 75 85 95
AIR FLOW (scfm)
GUN AIR INLET PRESSURE (psi)
Atomizing Pressure Versus
Activator Inlet Pressure
Air flowing through the gun creates back pressure,
which the activator must overcome before beginning to
flow . The chart below shows the minimum activator
pressure required to overcome the atomizing air
pressure. Higher pressures may be necessary to
maintain the mix ratio.
GUN AIR INLET PRESSURE (psi)
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
15 25 35 45 55 65 75 85 95
MINIMUM
ACTIVAT
OR INLET PRESSURE (psi)
Atomizing Air Pressure
(inlet pressure vs. atomizing pressure)
GUN AIR INLET PRESSURE (psi)
0
2
4
6
8
10
12
14
16
18
20
15 25 35 45 55 65 75 85 95
NOMINAL
AT
OMIZING PRESSURE (psi)
Gun Inlet Pressure Nominal Atomizing Pressure
15 psi (1.05 bar) 1.5 psi (0.1 1 bar)
25 psi (1.75 bar) 3.0 psi (0.22 bar)
35 psi (2.45 bar) 4.5 psi (0.33 bar)
45 psi (3.15 bar) 6.0 psi (0.42 bar)
55 psi (3.85 bar) 8.5 psi (0.62 bar)
65 psi (4.55 bar)* 10.0 psi (0.70 bar)
75 psi (5.25 bar) 13.0 psi (0.95 bar)
85 psi (5.95 bar) 15.5 psi (1.14 bar)
95 psi (6.97 bar) 18.0 psi (1.32 bar)
* For compliant operation, operate at 65 psi (4.55 bar) or less

6308-341
Installation
KEY
A Optimiser
2K Spray Gun
B Air Inlet; 1/4 npsm
C Air Hose
Recommend 5/16” (7.9 mm) ID hose;
Optional 3/8” (9.5 mm) ID hose
D Gun Air Shut-of f V alve
E
Gun Air Regulator
F Air Filter
G Air Supply Line
H Pressure Pot Air Shut-of f V alve
J
Pressure Pot Air Regulator
K Activator Pressure Pot
L Activator Fluid Shut-of f V alve
M
Activator Fluid Hose
N Activator Inlet 1/8–27 npt(f)
P Adhesive Pressure Pot
Q Adhesive Fluid Shut-of f V alve
R
Adhesive Fluid Hose
S Adhesive Inlet; 3/8 npsm (R3/8–19)
A
SB
NDEF
02750
G
C
HJ
HJKL
PQ
M
R
Fig.
1
Fluid Compatibility of Accessories
When selecting system components to supply the
adhesive and activator , consider the following:
 Adhesives and activators are water-based and
corrosive. A void carbon steel, unplated brass,
copper , and aluminum. Stainless steel, nickel-
plated brass and most plastics are usually accept -
able.

Piston pumps are not recommended for use with
adhesives as they are often shear sensitive and will
coagulate in your equipment. Stainless steel
pressure pots function well in place of a pump and
fluid pressure regulator. On drum or tote tank
supplied systems, plastic diaphragm pumps are
often used.
 Some adhesives will coagulate in fluid pressure
regulators due to shear . Consult with the fluid
supplier for regulator recommendations.
 Refer to Fig. 1 and see Form No. 305–591 for the
accessories recommended to install the system.
Consult with the fluid supplier or Graco for specific
recommendations.
Ventilate the Spray Booth
WARNING
FLAMMABLE/TOXIC FLUID HAZARD
T o avoid hazardous concentrations of
flammable or toxic fumes, spray only in
a properly ventilated spray booth.
Comply with all applicable local, state
and national fire and safety regulations.

308-3417
Installation
Air Line Accessories
The gun air line must have an air regulator (E) to
control air pressure to the gun. See Fig. 1.
 If the gun air source does not have a filter , install a
filter (F) on the gun air line to ensure a dry , clean
air supply .
T
o eliminate the need to shut of f the air pressure at
the air supply , install a quick-disconnect at the gun
air inlet fitting.
Fluid Line Accessories
If you are using diaphragm pumps to supply adhe -
sive or activator to the gun(s), install a fluid regula -
tor (T) on each gun fluid supply line to control fluid
pressure to the gun(s). See Fig. 9, page 9.
 Install a fluid filter in the gun fluid supply lines to
avoid clogging the fluid nozzle. A 100 mesh filter is
recommended for the activator supply line to avoid
clogging the activator needle and orifice.
 Use 5/32 or 1/4 inch I.D. tubing for the activator
supply line.
Setup and Shutdown
Pressure Relief Procedure
WARNING
PRESSURIZED EQUIPMENT HAZARD
The equipment stays pressurized until pressure is
manually relieved. To reduce the risk of serious
injury from pressurized fluid, accidental spray from
the gun or splashing fluid, follow this procedure
whenever you:
 Are instructed to relieve pressure
 Stop spraying
 Check, clean or service any system equipment
 Install or clean fluid nozzles
1. Close the adhesive and activator shut-of f valves
(Q and L). See Fig. 2.
2. T rigger the gun into the spray booth* to relieve the
fluid pressures and clear excess activator from the
gun. See Fig. 3.
*If the gun has been flushed with solvent, be sure to spray
the solvent into a grounded metal waste container .
3. Close the atomizing air shut-of f valve (D). See
Fig. 4.
Fig. 2
L
02059
Q
Fig. 3 02753
Fig. 4
D
02780

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Setup and Shutdown
Removing and Installing the Fluid Nozzle
Follow this procedure whenever you remove and install
a fluid nozzle. See page 4 to select a nozzle or
needle/nozzle/air cap kit.
1. Follow the Pressure Relief Procedure on
page 7.
2. Remove the air cap ring (12), air cap (19), and air
cap seal (47). See Fig. 5.
3. T rigger the gun while you remove the fluid nozzle
(20) with the gun wrench (35).
Fig. 5 02757A
35 20
12, 19
47
17
Lightly lubricate baf fle o-ring (17)
Apply PTFE adhesive to nozzle (20) threads. T rigger gun and
tighten to 125–150 in-lbs (14–17 N Sm)
2
1
1
2
CAUTION
Trigger the gun whenever you tighten or remove the
fluid nozzle (20) to pull the needle away from the
nozzle seating surface and avoid scratching it.
4. Apply PTFE r adhesive to the threads of the fluid
nozzle (20) you are installing.
5. Lubricate the baf fle o-ring (17).
CAUTION
Lubricate the baf fle o-ring (17) before installing the
fluid nozzle (20). A dry o-ring will prevent the nozzle
from tightening properly and adhesive may leak
inside the gun.
6. T rigger the gun while you install the fluid nozzle
(20) with the gun wrench (35). T ighten it to 125 to
150 in-lbs (14 to 17 N Sm).
CAUTION
When tightening the fluid nozzle (20), do not exceed
150 in-lbs (17 N S m) torque. Over-tightening can
damage the nozzle, af fect the spray pattern, and is
unnecessary to guarantee a seal.
7. Install the air cap seal (47), air cap ring (12), and
air cap (19).

308-3419
Setup and Shutdown
WARNING
EQUIPMENT MISUSE HAZARD
This gun is for use with water-based contact adhe-
sives only. Any other use of the gun could cause
unsafe
operating conditions or damage to the gun.
1. Connect the air line.
A. Connect the air hose (C) to the gun air inlet
(B). See Fig. 6.
C
B
02751
Fig. 6
1
11/4
npsm
B. Connect the other end of the air hose (C) to a
regulated air supply line (G). See Fig. 7.
NOTE: Fig. 7 shows the air supply line filter (F), air
regulator (E), and air shut-of f valve (D).
01990
C
EF
Fig. 7
G
D
2. Flush the adhesive and activator fluid
lines with water and blow them out
with air before connecting them to the
gun.
3. Connect the adhesive fluid hose.
A. Connect the fluid hose (R) to the gun adhesive
inlet (S). See Fig. 8.
S
02752
Fig. 8
R
1
13/8–18
npsm [R 3/8–19]
compound thread
B. Connect the other end of the fluid hose (R) to
a regulated fluid supply line (U–see Fig. 9) or a
pressure tank (P–see Fig. 1, page 6).
NOTE: Fig. 9 shows the fluid supply line regulator
(T) and fluid shut-of f valves (Q).
R
T
02777
Fig. 9
U
Q

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Setup and Shutdown
4. Connect the activator tube.
A. Connect the fitting (V) and tube (M) to the gun
activator inlet. See Fig. 10.
B. Connect the other end of the fluid tube (M) to a
regulated fluid supply line or a pressure tank.
Fig. 10 02784
V
M
5. Position the Air Cap for a vertical or
horizontal spray pattern. See Fig. 11.
Vertical Pattern
Horizontal Pattern
Fig. 1 102020
6. Adjust the spray pattern.
WARNING
COMPONENT RUPTURE HAZARD
Do not exceed the 100 psi (7 bar)
maximum fluid and air pressure of this gun.
Higher pressures can cause parts to rupture and
result in serious injury .
NOTE: Refer to the Atomizing Pressure V ersus
Activator Inlet Pressure chart on page 5 to help set
air and activator pressures.
A. Close the fluid adjustment valve by turning the
knob (8) fully clockwise. Then turn the knob
counterclockwise four full turns to open it. See
Fig. 12.
02784
Fig. 12
8
Open
B. Open the adhesive fluid shut-of f valve (Q). Ad -
just the fluid flow with the fluid regulator (T)
installed in the gun fluid line (see Fig. 13) or
the air regulator on the adhesive tank (see Fig.
1). T ypical industrial flow rates will vary with
regulator pressures from 5 to 20 psi (0.35 to
1.4 bar).
Fig. 13
T
02778
Q