Paint_Process_Standard_CA_8800_V3.1_Oct_2010.pdf

Revised October 2010

CA 8800 Paint Process Standard for

Exterior Commercial Aircraft

Issue date: 10/2010 Process Standard Supercedes: 06/2003

Table of Contents

Tables Page 2

Application Guidelines Page 3

Use Page 3

Materials Page 3

Surface Preparation Page 5

Spray Equipment Page 5

Fluid Flow Rate Page 6

Air Pressure Settings Page 6

Primer Mixing Page 7

Primer Application Page 8

Accelerated Cure Page 9

Surface Preparation before Topcoating Page 9

Topcoat Mixing Page 9

Pot Life Page 9

Topcoat Application Page 10

Adjustments for Application Conditions Page 10

Application of Non-Metallic Metallic (mica) Topcoats Page 11

Sand and Repaint Page 11

Accent Color Application Page 12

Roller Application Page 12

Surface Preparation Page 12

Equipment Page 12

Mixing Page 12

Rolling the Topcoat Page 13

Clear Coating Solid Colors Page 13

Decals Page 13

Topcoat Repair Page 13

Clean Up Page 14

Paint Defects and Solutions Page 14

Craters (Pin Holes, Dewetting, Or Fisheyes) Page 14

Orange Peel Page 14

Microblistering Page 15

Sagging Page 15

Flooding and Floating Page 15

Coating Maintenance Page 15

Health and Safety Page 15

Tables

Table I Air Pressure Settings Page 5

Table II Primer Mix Ratio Page 6

Table III Primer Induction Times Page 6

Table IV Primer Pot Life Page 6

Table V Primer Dry Times Page 7

Table VI Desothane HS CA 8000 Topcoat Pot Life

With Various Thinners Page 8

Table VII Desothane

HS CA 8000 Cure Characteristics

With Various Thinners Page 9

Table VIII Mix Ratio for Rolling Desothane

HS

Topcoats Page 11

Table IX Dry Times and Pot Life for Rolling

Desothane

HS White and Gray Topcoats Page 13

Table X Dry Times and Pot Life for Rolling

Desothane

HS Topcoats (All Other Colors) Page 13

Application Guidelines

Use

Desoprime

TM

epoxy primers and Desothane HS polyurethane topcoats referenced in this document have been formulated for the exterior surfaces of aircraft. They meet the stringent durability, adhesion, and corrosion resistance requirements of Boeing, Airbus, and other OEM’s. These coatings have been through extensive testing and field service evaluations and are currently in use at airframe manufacturers, airlines, and third party paint facilities worldwide.

Materials

Description PRC-DeSoto International

Code Number Specification

Mix ratio (by volume)

Coating Removers

EDPR-3500

• AMS 1375

• Boeing D6-17487

• Douglas CSD #1

• Embraer

PR-3500

PR-2002 EDPR-2002

• AMS 1376A

• DPM 5619

PR-5044 EDPR-5044

• BAC 5725

• Boeing D6-17487

• DPM 5549

Alkaline Cleaners

EDALK-774

• MIL-PRF-87937D,Ty IV

ALK-774

ALK-600 EDALK-600 • MIL-C-87936A,Ty 1

ED-500

EDED-500

• MIL-C-25769H

• Bell Helicopter

Astromat H

EDASTRO-H

• Douglas CSD #1

• Boeing D6-17487

• AMS 1526A

Conversion Coating

EDDK-4

• MIL-C-5541

• MIL-C-81706

Dorado Kote #4

Adhesion Promoters

EDEAP-9

• BMS 10-128, Ty 1, Cl A, Gr A

Desogel

TM

EAP-9

Desogel

TM

EAP-12

EDEAP-12

• BMS 10-128, Ty 1, Cl A, Gr A

Deoxidizers

EDAC-5

• AMS 1626

• Boeing D6-17487

AC-5

AC-12

EDAC-12

• AMS 1640

• Douglas CSD #1

• Chinese Aviation Authority

• MIL-C-38334, Ty 1, Cl 1

EAC-8 EDAC-8

EAC-8T EDAC-8T

Solvent Cleaners 020K019

• BAC 5750

Desoclean

110 cleaner

45 cleaner 020X413

• STM0752

• DPM 8226

• BAC 5322

120 cleaner CA 0120

Desoclean

TM

130 cleaner CA 0130

High Solids Exterior Primers

• Base: CA 7700A, CA 7755A

• Activator: CA 7700B or CA 7700BE, CA 7755B or CA 7755BE

• BAMS 565-008

• MEP 10-068

• Raytheon

1:1 Desoprime

TM

HS primer

Desoprime

TM

HS primer Chrome Free

• Base: CA 7501A, CA 7502A

• Activator: CA 7501B, CA 7502B

• Thinner: CA 7502C

• Optional compliant thinner for CA

7501 primer: CA 1800CX

• BMS 10-118

1:1 for CA 7501 1:1:1/2 for

CA 7502

Filler Surfacer

• Base: CA 7650 A

• Activator: CA 7650 B

• BAMS 565-015

1:1

Desofill

TM

HS Gray Filler Surfacer

Urethane Topcoat • Base: CA 8800

• Activator: CA 8800Z

• Thinner: CA 8800CT, CA 8800CT1, CA 8800CT2, CA 8800CT3, CA

8800CT4, CA 8800CT5

• BAMS 565-009,

• MEP 10-069

• DPM 6546

2:1:1 Desothane

HS

Specialty

• Base: CA 8800/B900

• Activator: CA 8800Z

• Thinner: CA 8800F

• BAMS 565-009

• MEP 10-069

• DPM 6546

• BMS 10-72 Type VIII

• BMS 10-125 Type III

2:1:1 Clear coat

Decal Edge Seal

• Base: CA 8000/B900B

• Activator: CA 8000B

• BAC 5312 1½:1

Roller Additive

• Base: CA 8800 series

• Activator: CA 8800Z

• Roller Additive: CA 8000R

See Table VIII

(page 11)

Desobond CA 100 Adhesion Promoter

• Base: CA 100 A

• Activator: CA 100 B

• DPM 6568 1:1

Coating Maintenance F1A90210

• D6-17487

• AMS 1650C

Green

ED-403 EDED-403

Astromat ODF EDASTROODF

• Douglas CSD#1

• AMS 1533A

Surface Preparation

Surface preparation is extremely important for good adhesion, chemical resistance, corrosion resistance, and appearance. Customer preferences for pre-paint preparation and materials will vary. The following procedures are recommended by PPG Aerospace, PRC-DeSoto on non-anodized surfaces.

1. Strip the aluminum surfaces with a PRC-DeSoto coating remover (i.e. PR 5044, PR 2002, etc.)

consistent with the data sheet guidelines. .

2. Rinse with warm water.

3. Apply an alkaline cleaner such as Astromat H, ALK-774 (EU compliant), ALK-600 or ED-500 and rinse thoroughly with warm water. Agitating the surface with red or grey Scotch Brite pads is recommended. Take care not to let the alkaline cleaner dry on the surface. Dried alkaline cleaner leaves a residue that is difficult to see or remove. Evaluate the surface for streaking.

4. Power abrade the surface with abrasive pads, and water. Clean thoroughly with a mild solvent or solvent blend, such as Desoclean

TM

110 cleaner.

5. Deoxidize the surface with an acid brightener such as AC-5, AC-8 or AC-12. AC-8 is a fluorine free formulation. Acid brightening is an aggressive surface treatment and should always be performed by experienced staff. Agitate the brightener with abrasive pads. Do not power abrade.

Make sure the surface is water break free for a minimum of 20 seconds. If not water break free, hand abrade with diluted brightener, then recheck the surface for water breaks.

6. Apply a chromate conversion coating, Dorado Kote #4 is recommended. Use care not to exceed the recommended surface dwell time. Rinse thoroughly with warm water.

7. For a chrome free pretreatment or when using a chrome free primer, Desogel EAP-9 or EAP-12 should be used in place of Dorado Coat #4. The surface preparation process can be modified to eliminate the deoxidation step when using Desogel. It is critical to alkaline rinse and abrade the surface until a 30 second water break free surface is achieved. Review the Desogel application guide for more details.

8. Allow the surface to dry before applying the primer, making sure there is no residual water in the seams.

Note: Some aircraft have anodized skins. After an anodized aluminum aircraft is stripped down to the anodized aluminum, power abrade the surface with an abrasive pad, wipe clean with a mild solvent, or solvent blend, such as Desoclean

TM

110 cleaner, then apply a chromate conversion coating, Dorado Coat # 4. Rinse with warm water (not to exceed) and allow the surface to dry before applying PPG Aerospace, PRC-DeSoto epoxy primer.

Note: The PPG paint stripping guide and data sheets for individual products provide additional detail on product use.

Spray Equipment

PPG Aerospace, PRC-DeSoto primers and topcoats are formulated for use with all types of spray equipment. Recommended tip sizes and pressure settings are summarized below. The final appearance depends on many factors. In general, small particles will create a smoother film with less orange peel. Air spray or HVLP atomize the paint more effectively than airless or assisted airless spray equipment and are recommended for Desoprime

TM

HS primers and Desothane

HS topcoats.

Electrostatic Air Spray Gun

Tip Size 1.2 mm or 1.5 mm (or equivalent)

Pot Pressure 16 to 20 psi (1.1 to 1.4 bar) or the amount of pressure to yield 8 to 12 ounces per minute fluid flow.

Atomization Pressure at the Cap 45 to 60 psi (3.1 to 4.1 bar)

Electrostatic Air Assisted Airless Spray Gun

Tip size #611 or #613 (GRACO Nomenclature)

Fluid Pressure 700 to 1800 psi (48 to 124 bar)

Atomization Pressure at the Cap 40 to 50 psi (2.8 to 3.5 bar)

High Volume Low Pressure Spray Gun (HVLP)

Tip Size 1.0 to 1.4 mm (or equivalent)

Pot Pressure 10 to 20 psi (0.69 to 1.4 bar)

Atomization Pressure at the Cap 10 psi maximum (0.69 bar)*

Conventional Air Spray Gun

Tip Size 1.2 to 1.8 mm (or equivalent)

Pot Pressure 10 to 20 psi (0.69 to 1.4 bar) or the amount of pressure yield 8 to 12 ounces per minute of fluid flow

Atomization Pressure at the Cap 45 to 60 psi (3.1 to 4.1 bar)

Note: 1 psi = 0.0689 bar

* Spraying in excess of 10 psi at the air cap will cause “dry spray” with HVLP spray equipment and violate the rules concerning HVLP spray equipment.

Fluid Flow Rate

To determine fluid flow rate of spray equipment, turn off the atomizing air at the pump. Enclose the air cap of the spray gun with a solvent resistant plastic bag. If more than one gun is being used from one pump, then both triggers must be pulled to draw pressure from the pump. Pull the trigger on the enclosed gun for 15 seconds. Remove the bag and transfer all the captured paint into a graduated container.

Multiply the contents by 4 and this will be the flow rate per minute. The suggested flow rate to minimize sagging and orange peel is 8 to 12 ounces (227 to 340 milliliters) per minute. The flow rate can be adjusted by increasing or decreasing the fluid pressure or by changing the tip size.

Air Pressure Settings

In order to achieve 45 to 60 psi (3.1 to 4.1 bar) air atomization pressure at the gun, the regulated pressure at the mixing pot should be set higher to compensate for pressure losses. Table I shows regulator pressure requirements for different hose length.

Table I - Air Pressure Settings

Air Hose Length Air Regulator Pressure

4 feet (1.2 meters) 45 psi (3.1 bar) 15 feet (4.6 meters) 50 psi (3.4 bar) 25 feet (7.6 meters) 55 psi (3.8 bar)

36 feet (11.0 meters) 65 psi (4.5 bar) 50 feet (15.2 meters) 70 psi (4.8 bar) 75 feet (22.9 meters) 85 psi (5.9 bar) 100 feet (30.5 meters) 100 psi (6.9 bar)

Material Inspection Prior To Use

Inspect containers for damage during shipping. Open any bulging cans with extreme caution. Do not put the activator component on a paint shaker. Initially, the CA 7700 series curing solution (Activator) may appear to have soft settling. After hand stirring, the curing solution (Activator) will be a cloudy (milky) amber solution.

Primer Mixing

Note: It is important to condition the primer for 24 hours prior to mixing by placing it in the shop or hangar, with ambient temperatures between 55° to 95°F (13° to 35°C). The minimum temperature of the paint components should be 55°F (13°C) prior to mixing.

Be sure all mixing and measuring containers are clean and free of contamination. Paper mixing cups must not have a solvent soluble (i.e. wax) lining. These linings will contaminate the primer.

CA 7700 series primers are available for use with either the “B” or “BE” activator; the “BE” activator was designed for improved electrostatic spray applications. For all PPG Aerospace, PRC-DeSoto primers it is important to shake the base component for 10 to 15 minutes on a paint shaker or stir thoroughly until there is no solid material on the bottom of the can. Always add components in the order shown on label.

All components should be mixed at the proper ratios (outlined below) to achieve the optimum performance properties and the correct VOC. Failure to mix properly will affect the application characteristics and film properties. Avoid mixing old primer with freshly mixed primer. This will reduce the pot life of the freshly mixed primer, cause severe orange peel, and decrease the wet edge time.

Table II – Primer Mix Ratio

Base Activator Thinner Mix Ratio Type

CA 7700A CA 7700B or CA 7700BE None 1:1 High Solids CA 7755 A CA 7755B or CA 7755BE None 1:1 High Solids CA 7501A CA 7501B None 1:1 High Solids CA 7502A CA 7502B CA 7502C 1:1:1/2 High Solids

To improve the spray characteristics of Series CA 7700 or CA 7500 primers and additional compliant thinner, CA 1800CX or CA 1805CX, may be added. This will not increase the VOC. The suggested level of thinner is up to 20% by volume. Do not use thinners or flow control agents from other manufacturers.

These often contain material that will degrade the cure, adhesion, or appearance of the primer

Table III – Primer Induction Time

An induction time is required for Desoprime

TM

epoxy primers. The induction time is based on the ambient (external) temperatures as outlined on Table III below. Mild agitation during the induction period is highly recommended.

Mixed Primer (mix ratio by volume)

55°– 64°F (13° - 17°C)

65° – 74°F (18° – 23 °C)

75° - 84°F (24° – 28°C)

85°F (29°C) or greater

CA 7700A + CA 7700B

(1:1)

1½ hours, minimum

1 hour, minimum

45 minutes, minimum

30 minutes minimum

CA 7700A + CA 7700BE

(1:1)

1½ hours, minimum

1 hour, minimum

30 minutes, minimum

15 minutes, minimum

CA 7501A+ CA 7501B

(1:1)

1½ hours, minimum

1 hour, minimum

45 minutes, minimum

30 minutes, minimum

CA 7502A + CA 7502B +

CA 7502C (1:1:0.5)

1 ½ hours, minimum

1 hour, minimum

30 minutes, minimum

15 minutes, minimum

Table IV – Primer Pot Life

The pot life for the primers is based on the ambient temperatures as outlined on Table IV below.

Mixed Primer (mix ratio by volume)

55° – 64°F (13° – 17°C)

65° – 74°F (18° - 23°C)

75° - 84°F (24° – 28°C)

85° - 95°F (29° - 34°C)

95°F (35°C)

CA 7700A + CA 7700B (1:1) 6 hours 6 hours 6 hours 6 hours 6 hours

CA 7700A + CA 7700BE (1:1) 5 hours 4 hours 3 hours 2 hours 1 hour

CA 7501A+ CA 7501B (1:1) 6 hours 6 hours 6 hours 6 hours 6 hours

CA 7500A + CA 7500B +

CA 7502C (1:1:1/2)

5 hours 4 hours 3 hours 2 hours 1 hour

Strain mixed primer through a fine mesh cloth to remove any particles that may have been introduced into the primer during mixing and measuring. Stir the mixed primer during the induction period and when in use. Stirring will minimize settling and maximize the physical properties. Discard any unused material that has exceeded it usable pot life. A primer that has exceeded its usable pot life may still have low viscosity, but will develop severe orange peel.

Primer Application

Ground the aircraft and the application equipment before priming. Slowly stir the primer slowly during application.

The temperature of primer should be equal to the shop or hangar temperature before application.

Apply the primer to an average dry film thickness of 0.6 to 1.2 mils (15 to 30 microns). One medium coat with a 50% overlap is recommended. After applying primer a close inspection of the primer film is recommended to ensure a continuous coating was applied. If there are small pinholes in the dried primer, reapply the primer to completely cover the substrate. Primer thickness below 0.6 mils may have adhesion problems and cannot be sanded. Primer thickness exceeding 1.2 mils is not a performance concern. Excessive primer thickness will only add weight to the plane and will increase dry time. When CA 7000 series or CA 7700 series primers are applied from 0.6 to 1.2 (15 to 30 microns), the primer film will appear translucent. The primer should not be applied to full hide.

Table V – Primer Dry Times*

CA 7700 w/ “B” or “BE” Activator

60°F (15°C) 70°F (21°C) 80°F (27°C) 90°F (32°C)

Dust Free 3 – 4 hours 2 – 3 hours ½ – 1½ hours ¼ – 1¼ hours Dry-to-Tape 4 – 5 hours 3 – 4 hours 2 – 3 hours 2 – 3 hours Dry-to-Walk 5 – 7 hours 4 – 6 hours 3 – 5 hours 3 – 5 hours Dry-to-Topcoat Minimum Maximum

2 hours 72 hours

2 hours 72 hours

2 hours 72 hours

2 hours 72 hours

Dry-to-fly 96 hours 72 hours 48 hours 24 hours CA 7501 and CA 7502 60°F (15°C) 70°F (21°C) 80°F (27°C) 90°F (32°C)

Dust Free 3 – 4 hours 2 – 3 hours ½ –1½ hours ¼ – 1¼ hours Dry-to-Tape 4 – 5 hours 3 – 4 hours 2 – 3 hours 2 – 3 hours Dry-to-Walk 5 – 7 hours 4 – 6 hours 3 – 5 hours 3 – 5 hours Dry-to-Topcoat Minimum Maximum

2 hours 72 hours

2 hours 72 hours

2 hours 72 hours

2 hour 72 hours

Dry-to-fly 96 hours 72 hours 48 hours 24 hours

Full cure for all primers is 7 days for all times and temperatures. Actual dry times may vary and are dependent upon film thickness, airflow and spray technique. Lower film thickness, better airflow, and spraying “dry” will decrease the dry-to-tape and dry-to-walk.

Accelerated Cure

CA 7700 and CA 7500 High Solids Primers: Allow 30 minutes flash off at 75° ± 10°F (24° ± 5.6°C) followed by 30 minutes at 120°F (49°C) for dry-to-topcoat.

Surface Preparation before Topcoating

If the primer exhibits surface defects such as dry spray or visible dust particles, hand scuff with abrasive pads and remove dust with a mild solvent or solvent blend, such as Desoclean

TM

110 cleaner. A urethane compatible tack rag may be used to remove dust on the surface. Do not use excessive pressure when using a urethane compatible tack rag. Tack rag residue can be left on the primer surface and cause craters or swirl marks. Never use a tack rag wet with solvent.

If the primer is less than 72 hours old, the topcoat can be applied without any further surface preparation.

Ensure the surface is clean prior to applying any topcoat.

If the is over 72 hours old, the surface may be lightly scuffed with abrasive pads or 240-grit (or finer) sandpaper. Remove any dust or debris with a mild solvent or solvent blend, such as Desoclean

TM

cleaner then wipe dry with a lint-free cloth. Do not allow the solvent to dry on the surface. A urethane compatible tack rag may also be used to remove the dust or debris.

An alternative method of activating the aged PRC-DeSoto primer is to apply a thin coat of Desobond CA 100 Adhesion promoter (approximately 0.1 mils). After the CA 100 has dried for 2 to 24 hours, Desothane HS may be applied. This eliminates sanding.

Topcoat Mixing (Desothane® HS CA 8800 Polyurethane Topcoat)

Inspect containers for damage during shipping. The condition of the curing solution is important. Do not use a curing solution whose container is bulging or if the solution is hazy or contains gelled particles.

These are all indications of moisture contamination. The solution should be clear pale yellow to clear amber in color.

Note: It is important to condition the paint for 24 hours prior to mixing by placing in the shop or hangar, with ambient temperatures between 55° to 95°F (13° to 35°C). The minimum temperature of the paint components should be 55°F (13°C) prior to mixing.

Be sure all mixing and measuring containers are clean and free of contamination. Paper mixing cups must not have a solvent soluble (i.e. wax) lining. These linings will contaminate the coating.

Shake the base component for 10 to 15 minutes on a paint shaker or stir thoroughly until there is no solid material on the bottom of the can. Note: Non-Metallic Metallic (Mica pigment) colors may take longer to re-disperse. Before mixing, consider the amount of surface area to be topcoated and the approximate amount of time needed to apply each coat. Select the thinner that will provide the necessary wet edge, re-coat time, dry-to-tape, and pot life to optimize the appearance and application. (see Table VII)

Mixing Instructions: When mixing the topcoat, always add components in the order shown on the label. Mix one (1) part CA 8800Z curing solution to two (2) parts CA 8800 base component, and add one

(1) part CA 8800CT series thinner (flow control). Mix thoroughly for 5 minutes to make sure the material is homogeneous. Always add components slowly while agitating. Stir the topcoat slowly when in use.

Do not under thin or over thin the topcoat. Desothane

HS topcoat was formulated to yield a smooth finish as mixed. Too much thinner may cause sagging; too little thinner will cause orange peel.

Pot Life

Desothane HS topcoats are ready to spray as soon as thoroughly mixed. Freshly mixed Desothane

HS topcoat has the best appearance. Strain the material through a fine nylon cloth to remove any particles that may have been introduced during mixing. Stir the mixed material before and during use.

Discard any material that has exceeded its pot life.

Table VI – Desothane® HS CA 8800 Topcoat Pot Life with Various Thinners

Thinners 68°F (20°C) 77°F (25°C) 87°F (30°C) 95°F (35°C)

CA 8800CT and

CA 8800 CTR

4 hours

3 hours

2.5 hours

2 hours

CA 8800CT1 2.5 hours 2 hours 1.5 hours 1 hour CA 8800CT2 1.5 hours 1 hour 45 minutes 30 minutes CA 8800CT3 1 hour 45 minutes 30 minutes 20 minutes CA 8800CT4 45 minutes 30 minutes 20 minutes 15 minutes CA 8800CT5 30 minutes 20 minutes 15 minutes 12 minutes

Topcoat Application

Apply 2 or 3 coats of Desothane HS topcoat to a dry film thickness of 2.0 to 3.0 mils (50 to 75 microns).

The following recommendations will help avoid sags and tear drops around fasteners and also reduce orange peel.

Apply a medium first coat with a maximum wet film thickness of 2 mils (50 microns). It is important to apply a smooth uniform coat to minimize orange peel. Heavy orange peel in the first coat will show through the second coat. If a very thin first coat is used, it may be necessary to apply a total of three coats to cover up the roughness of the first coat.

The first coat should start to “tack up” before applying the second coat. Tacking up means the paint WILL transfer to the finger, but there should be resistance as the finger is pulled off the surface. A tacky surface will feel like the sticky side of masking tape. If the second coat is applied before the first coat is tacky, there will be sagging. If the first coat is allowed to dry completely (no transfer to the finger) then the second coat may not wet out the first coat causing severe orange peel. In extreme hot weather conditions (100°F+ / 38°C+), CA 8800 may dry too fast. CA 8800 CTR is recommended to be used as a retarder.

This will increase the wet edge and the time between coats without increasing the dry times.

For best appearance the second coat of Desothane HS topcoat should be freshly mixed. Material aged in the paint pot will have poor wet edge and flow, even if the measured viscosity hasn’t changed. The second coat should be applied slightly thicker than the first coat with a maximum wet thickness of 2.5 mils (62 microns).

Adjustments for Application Conditions

Desothane HS topcoats can be applied at high and low temperatures. The cure temperature does not affect the superior film properties, just the dry time. Desothane

HS topcoats are not affected by humidity.

Moisture in the air, or the lack of it, doesn’t affect the cure or appearance. As an example Desothane

HS topcoat has been successfully sprayed between 2% and 95% relative humidity.

To fine-tune the cure of Desothane HS topcoat use Table VII. It is important to use the thinner that will optimize the cure time and the wet edge. For example at 95°F (35°C) using CA 8800CT2 thinner for a large area would have poor appearance due to poor wet edge. At 68°F (20°C) using CA 8000CT2 thinner would be very appropriate.

Table VII – Desothane® HS CA 8800 Topcoat Cure Characteristics with Various Thinners*

68°F (20°C) Thinners Dry to tape Wet edge Time between coats Dry to fly

CA 8800CT 9 – 12 hrs 45 – 60 min 50 – 100 min 90 hrs CA 8800CT1 7 – 10 hrs 25 – 40 min 40 – 60 min 65 hrs CA 8800CT2 4 – 5 hrs 15 – 30 min 35 – 45 min 40 hrs CA 8800CT3 3 – 4 hrs 10 – 15 min 30 – 40 min 24 hrs CA 8800CT4 2 – 3 hrs 5 – 10 min 15 – 20 min 12 hrs CA 8800CT5 1 – 2 hrs 3 – 5 min 10 – 15 min 8 hrs

77°F (25°C) Thinners Dry to tape Wet edge Time between coats Dry to fly

CA 8800CT 8 – 12 hrs 30 – 45 min 45 – 60 min 72 hrs

CA 8800CT1 5 – 7 hrs 15 – 30 min 30 – 45 min 48 hrs CA 8800CT2 3 – 4 hrs 10 – 15 min 20 – 30 min 24 hrs CA 8800CT3 1.5 – 2.5 hrs 8 – 12 min 15 – 20 min 12 hrs CA 8800CT4 1 – 1.5 hrs 3 – 5 min 10 – 15 min 8 hrs CA 8800CT5 45 – 60 min 2 – 4 min 7 – 13 min 6 hrs

87°F (30°C) Thinners Dry to tape Wet edge Time between coats Dry to fly

CA 8800CT 6 – 9 hrs 25 – 40 min 40 – 55 min 55 hrs CA 8800CT1 3 – 6 hrs 10 – 25 min 25 – 35 min 30 hrs CA 8800CT2 2 – 4 hrs 8 – 15 min 15 – 25 min 18 hrs CA 8800CT3 1.5 – 3 hrs 6 – 12 min 10 – 15 min 10 hrs CA 8800CT4 45 – 60 min 5 – 10 min 8 – 12 min 6 hrs CA 8800CT5 35 – 50 min 4 – 8 min 6 – 10 min 4 hrs

95°F (35°C) Thinners Dry to tape Wet edge Time between coats Dry to fly

CA 8800CT

CA 8800CTR

5 – 8 hrs 5 – 8 hrs

20 – 30 min 30 -45 min

30 – 40 min 40 – 60 min

36 hrs 36 hrs

CA 8800CT1 3 – 5 hrs 10 – 20 min 15 – 30 min 24 hrs CA 8800CT2 2 – 3 hrs 5 – 10 min 10 – 20 min 12 hrs

*The ranges listed above are dependent upon the film thickness, airflow, and spray technique. Lower film thickness, better airflow, and spraying “dry” will decrease the dry to tape, wet edge, and time between coats.

Application of Mica Topcoats

This section is for applying non-metallic metallic (mica) topcoats as accent colors. For painting a large area, there is a guide available, “Desothane

HS CA 8000 Application Guide For Nonmetallic/Metallic

(Mica) Flake Metallic/Desothane Clearcoat.” This guide can be obtained from a PPG Aerospace, PRC- DeSoto representative.

For improved appearance and color consistency, a solid color base coat is recommended when using CA 8000 or CA 8800 Mica Desothane

HS topcoats. For a silver mica color use a white or gray base coat.

For a mica gold a yellow base coat such as BAC 329 is recommended. After the base coat “tacks up”, apply two or three dry coats of non-metallic (mica) or until full opacity is obtained. If the color doesn’t look consistent, apply another very dry coat. Spraying multiple dry coats improves the appearance. After the final coat of non-metallic metallic (mica) is “tack free”, apply one or two coats of CA 8800/B900 clear coat.

SAND AND REPAINT

The fuselage and wings are not always stripped before painting. The aged paint may be sanded before re-painting. The recommended procedure is:

1. Prior to sanding inspect the substrate to assure the aged paint system is of sound condition.

Areas of bubbles, blisters, etc. should be inspected to assure the substrate is free of corrosion.

2. If sanding is warranted carefully sand the polyurethane painted surface to remove the gloss, minimizing the amount of exposed aluminum. For a smooth surface, sand with 400-grit paper.

3. Wipe the sanded surface clean with a mild solvent or solvent blend, such as Desoclean

TM

cleaner. Do not use a strong solvent like Methyl Ethyl Ketone (MEK). Dust and debris may also be removed with a urethane compatible tack rag.

4. Where metal is showing, apply a thin coat of PPG Aerospace, PRC-DeSoto epoxy primer with a Sempen applicator or touch up gun.

5. Allow the primer to dry for 2 hours and then apply two coats of Desothane HS polyurethane topcoat.

6. An alternative is to skip the sanding step and use Desobond CA 100 adhesion promoter. The surface to be recoated has to be thoroughly cleaned using a strong solvent cleaner, such as Desoclean 45. Next apply a thin coat of CA 100 (0.1 mil), wait 1 hour and then topcoat.

Accent Color Application

Before applying accent colors it is important to allow the main body colors to dry well enough to avoid marking with masking tape. To test the topcoat to find out if it is dry to tape, apply a small piece of tape for 10 minutes and remove. Lightly polish with a soft cloth. The coating is ready to be masked if there is no tape residue.

Caution: A freshly painted surface SHOULD NOT BE COVERED WITH PLASTIC OR NON-POROUS PAPER. Depending upon the ventilation in the hangar, the topcoat should cure for 24 to 48 hours before covering it with plastic. The trapped solvents from the paint will damage the surface and lower the gloss.

Porous paper is recommended to use over freshly applied paint.

The recommended procedure for applying accent colors is:

1. If the main body color is less than 24 hours old, the accent colors can be applied without abrading.

2A. If the main body color is over 24 hours old, the surface may be lightly abraded with an abrasive pad or 320- grit (or finer) sandpaper to remove the gloss. Clean the surface with a mild solvent, or solvent blend, such as Desoclean

TM

110 cleaner, and then apply the accent color

2B. An alternative method (if the main body color is over 24 hours old) is to apply a thin coat of Desobond CA 100 Adhesion Promoter. The film thickness should be 0.1 mils (12. microns). When the thin coat of CA 100 is cured for 2 to 24 hours, apply the topcoat.

Roller Application

Surface Preparation

If the surface to be rolled is already painted, the surface should be lightly sanded with an abrasive pad or 320-grit (or finer) sandpaper then wiped with a mild solvent, or solvent blend, such as Desoclean

TM

cleaner to remove any dust or debris. A thin coat of Desobond CA 100 can be used instead of sanding.

Urethane compatible tack rags may also be used to remove dust and debris. Where metal is showing, apply a thin coat of PPG Aerospace, PRC-DeSoto conventional or high solids epoxy primer with a Sempen applicator or touch up gun.

EQUIPMENT

It is recommended to use a solvent resistant foam roller. A Mohair roller is not recommended because it can add fibers to the finish.

MIXING

Desothane HS topcoats can be rolled successfully by using roller additive, CA 8000R for small areas or

CA 8200R for large areas. These roller additives were designed to reduce air bubble entrapment and improve the final appearance. CA 8000R is very fast drying and is used for touch-up areas while CA 8200R has a much longer wet and is used for larger areas, such as wings.

Table VIII – Mix Ratio for Rolling Desothane® HS CA 8800 Topcoats

Base Activator Thinner* Roller

Additive

CA 8800

2 volumes

CA 8800 Z

1 volume

CA1805CX

0.25 – 1.4 volume

CA 8000R

0.25 volume

CA 8800

2 volumes

CA 8800 Z

1 volume

CA1805CX

0.25 – 1.4 volume

CA 8200 R

0.25 volume

* If rolling is performed on a flat horizontal surface, such as the top of a wing, additional thinner (greater than 0.5 volume of CA1805CX) may be added to the mixed material

ROLLING THE TOPCOAT

It is important to load the foam roller with paint to displace the air in the foam cells. This will help reduce the bubbles. Roll freshly mixed topcoat in one or two coats to a uniform appearance that hides the underlying primer. Roll the topcoat to a total dry film thickness between 1.5 to 2.5 mils (37.5 to 62.5 microns). If the two-coat method is used, roll the second coat when the first coat is slightly tacky.

Table IX – Dry Time and Pot Life for Rolling Desothane® HS CA 8800 Topcoats with CA 8000R

Temperatures Dry to tape* Pot life Time between coats* Dry to fly

60°F (15°C) 4 – 5 hours 1½ hours 20 – 30 minutes 2½ days 72°F (22°C) 3 – 4 hours 45 minutes 15 – 20 minutes 12 hours 84°F (29°C) 2½ – 3 hours 30 minutes 10 – 15 minutes 10 hours 100°F (38°C) 1 – 2 hours 20 minutes 5 – 10 minutes 7 hours

Table X – Dry Time and Pot Life for Rolling Desothane® HS CA 8800 Topcoats with

CA8200 R

Temperatures Dry to tape* Pot life Time between coats* Dry to fly

60°F (15°C) 5 – 7 hours 2 hours 5 – 7 hours 3 days 72°F (22°C) 4 – 5 hours 1 hour 4 – 5 hours 18 hours 84°F (29°C) 3 – 4 hours 40 minutes 3 – 4 hours 15 hours 100°F (38°C) 1 – 2 hours 30 minutes 2 – 3 hours 12 hours

• The ranges listed above are dependent upon film thickness and airflow. Lower film thickness and better airflow will decrease the dry to tape and time between coats.

Clear Coating Solid Colors

Desothane HS topcoats can be clear coated to improve exterior durability. When the final color coat is tack free, a single coat of CA 8800/B900 clear may be applied to a dry film thickness of 0.9 to 1.1 mils (23 to 28 microns). Care should be taken to use the same dry time thinner as the color coat. As an example if the color coat is thinned with CA 8800 CT, then the clear should be thinned with CA 8800 F. If the color coat uses CA 8800 CT1, then the clear should be CA 8800 F1. If the clear coat is thinned with a faster drying thinner, solvent will be trapped ruining the appearance. At very high temperatures and high humidity (over [32C] and above 80%), it may be appropriate to use a retarder solvent for the clear, CA

8800 FR.

Decals

Un-perforated decals should be applied to the topcoat after a minimum of 24 hours cure at 77°F (25°C).

This will allow sufficient time for the solvents to evaporate. However, perforated decals can be applied as soon as Desothane

HS topcoat is dry-to-tape. PPG Aerospace, PRC-DeSoto recommends clear coating the edges of the decal with Desothane HS Edge Coat, CA 8000/B900B to extend the service life.

Topcoat Repair

To repair the topcoat, lightly hand scuff the surface with an abrasive pad or 320-grit (or finer) sandpaper, Solvent wipe the surface with a mild solvent, or solvent blend, such as Desoclean

TM

110 cleaner, to remove dust and debris then apply the Desothane HS topcoat. Dust and debris may also be removed using a urethane compatible tack rag.

When repairing some colors, spray technique can affect the touch up color. As an example, a gray sprayed “wet” will cure lighter than the same material sprayed “dry”. A sagged area usually indicates a coating was sprayed too wet. To make a repair that has the same color, it is recommended to also spray it wet. Not too wet, but wet enough to have the same color as the adjacent area.

Clean Up

Clean spray equipment as soon as possible after use. Flush spray equipment with a strong ester or ketone solvent, or solvent blend, such as Desoclean

TM

45 cleaner. PPG Aerospace, PRC-DeSoto polyurethane topcoats, polyurethane sanding surfacers, epoxy topcoats and epoxy primers are chemically reacting systems that are not soluble in solvents after it has cured. For this reason, equipment should be cleaned as soon as possible after application and always before the material has cured. Even freshly applied coatings will deposit a film on the equipment that does not dissolve easily. Agitation with a brush or clean cloth will help to remove these deposits.

Paint Defects and Solutions

Craters (Pin Holes, Dewetting, Or Fisheyes)

Craters are caused by surface tension variation between the coating and the substrate. This causes the paint to be repelled from the area. Silicone, oil, hydraulic fluid, engine oil, and petroleum jelly are just a few of the possible causes of craters. Some of the sources for these contaminants are dirty substrates, oil and/or water in the compressed air lines, wrong lubricant used in the spray gun, sanding dust from composites, or a dirty filter in the airline. All potential sources of contamination should be isolated and eliminated to solve this frequent problem.

Orange Peel

To eliminate or reduce orange peel with Desothane HS topcoat:

1. Use air spray electrostatic or HVLP equipment. The droplet size of the paint is much smaller compared to airless or air assisted airless spray. If airless or air assisted airless must be used, it is suggested to increase the fluid pressure and decrease the tip size. This will make for smaller droplets and less orange peel.

2. The primer should be smooth. If the primer surface is rough, there will be more orange peel.

Desoprime HS CA 7700 and CA 7000 high solids primers have a smoother surface than conventional BMS 10-79 primers. If a conventional primer is used, the surface can be improved by lightly scuffing with a Scotch-Brite pad.

3. The proper thinner should be used. If the weather is warm, slower thinners, such as CA 8000C, are suggested. Slower dry time will improve the flow, increase the wet edge, and thereby reduce the orange peel.

4. Spray technique is very important. The painter should paint an area approximately 3 feet (one meter) wide. Depending upon the lighting it may be best to spray just to the side. The pass would extend from directly in front of the painter to as far as the painter can extend their arm. Another common problem is to break the wrist at the end of a pass, sometimes called “arcing”. To eliminate this, the wrist should be held steady to make sure an even amount of topcoat is applied per pass. Also, moving the gun too fast or holding it too far away will cause orange peel.

5. The first coat of Desothane HS topcoat is the most important. This all-important first coat should be applied as smoothly as possible. A smooth medium coat with a wet film thickness of 2 mils (50 microns) is desired. If the first coat is applied as a tack coat (less than 1 mil (25 microns)), it is very difficult to overcome the orange peel with subsequent coats.

6. Freshly mixed paint always has the least orange peel. Desothane HS topcoat at the end of the pot life will have a short wet edge and heavy orange peel. It is recommended the paint from the first coat be dumped prior to mixing the second coat. The smoothness of freshly mixed paint is better than the same paint at pot life.

7. Time between coats can affect the orange peel. When the first coat starts to tack up, apply the second coat. Waiting too long increases the orange peel. However, if the second coat is applied before the first coat tacks up, sagging can occur.

Microblistering

Desothane HS topcoats were designed to eliminate microblistering. There are some circumstances when even Desothane HS topcoat can microblister. This may occur at high temperatures, when the dry film thickness exceeds 4.0 mils (100 microns), the spray equipment is airless or assisted airless, and at the end of the pot life. Microblistering can be eliminated by using CA 8000 CTR retarder, mixing fresh material for each coat, using air spray or HVLP equipment, and limiting the dry film thickness to 3.0 mils (75 microns).

Sagging

The most frequent cause of sagging is applying the second coat of Desothane HS topcoat before the first coat tacks up. High fluid pressure in excess of 12 ounces (340 ml) per minute can also cause sagging. Sagging can be corrected by controlling spray technique and gun settings. Improved spray technique such as smooth strokes and not breaking the wrist will also eliminate sagging.

Flooding and Floating

Some colors are sensitive to flooding and floating. Most gray topcoats will flood and float because the black and white pigments are naturally incompatible. Sprayed “wet” the white pigment will come to the surface resulting in a lighter color. Spraying “drier”, using an air spray gun, and allowing a 45-minute induction time will help this phenomenon.

Coating Maintenance

Repeated washing of a painted surface contributes to the erosion of the resin layer that protects the gloss and color properties of the coating. To limit this erosion PPG specifically recommends Desoclean Green for dry washing and waxing a painted surfaces. It is specifically formulated to minimize the abrasive effects of washing on the painted surface. In addition, Desoclean Green applies a durable wax layer with UV inhibitors that will further protect and enhance the appearance of the coating.

PPG also manufactures other wet (Astromat ODF) and dry wash (ED-403) products that address specific operational or process requirements. Refer to the PPG Aircraft Washing guide for more details.

Health and Safety

These products are safe to use and apply when recommended precautions are followed. Before using these products, read and understand the PRC-DeSoto International “Safe Handling Guide” for aerospace coatings and Material Safety Data Sheet (MSDS), which provide information and environmental hazards, handling precautions, and first aid recommendations. An MSDS is available on request. Avoid overexposure. All mixing and rolling must be conducted with adequate ventilation and proper personal protective equipment as recommended. Obtain medical care in case of overexposure as outlined in Section III of the Material Safety Data Sheet (MSDS).

For more detailed product application information, contact a PRC-DeSoto International Technical Service Representative. See the Material Safety Data Sheet and Product Labels for any additional safety information and handling instructions.

For industrial use only. Keep away from children

EMERGENCY MEDICAL INFORMATION IN THE U.S.A. AND CANADA: 1-800-228-5635.

EMERGENCY MEDICAL INFORMATION (GLOBAL): 1-651-632-9265.

EMERGENCY SPILL CONTROL IN THE U.S.A.: 1-800-424-9300 (CHEMTREC).

EMERGENCY SPILL CONTROL INFORMATION IN CANADA: 1-613-996-6666 (CANUTEC).

Desoclean, Desoprime, Desothane, and Sempen are trademarks of PRC-DeSoto International, Inc.;

Desothane and Sempen are registered with the U.S. Patent and Trademark Office.

Graco is a trademark of Graco, Inc.

All recommendations, statements, and technical data contained herein are based on tests we believe to be reliable and correct, but the accuracy and completeness of said tests are not guaranteed and are not be construed as a warranty, either expressed or implied. User shall rely on his own information and tests to determine suitability of the product for the intended use and assumes all risks and liability resulting from his use of the product.

Manufacturer’s and seller’s exclusive responsibility shall be to replace that portion of the product that proves to be non-conforming. Neither seller nor manufacturer shall be liable to the buyer or any third person for any injury, loss, or damage directly or indirectly resulting from the use of, in inability to use, the product. Recommendations or statements other than those contained in a written agreement signed by an officer of the manufacturer shall not be binding upon the manufacturer or seller.

PRC-DeSoto International, Inc., 12780 San Fernando Road, Sylmar, CA 91342

In North America the contact number is: (800) AEROMIX www.ppgaerospace.com