1. Current Status AFRL Non-Chromium Coating System Integration Testing
May 2017
Diane Buhrmaster Materials Durability and Sustainment Branch Materials and Manufacturing Directorate

2. Current Status Test Type of Testing Status Notes
MIL-PRF including Outdoor Corrosion Testing
Qualification
Complete
4 fully non-Cr systems; standard flexibility, standard pigments, and not Skydrol resistant
Drying Time & Reparability of MIL-PRF coating systems
Integration
All systems passed compatibility testing (15 systems compared)
Sealant Paintability of Mg-Rich Coating Systems
Wet-Tape Adhesion testing completed; Excellent adhesion performance
PATTI Adhesion and Wet-Tape Adhesion of Mg-Rich Coating Systems applied at various Temps/Humidities
In Progress
Adhesion data for 6 coating systems, 5 Temp/Humidity conditions; Testing completed, data analysis in progress
MIL-PRF Subset of testing for Skydrol Resistance & Chemical Strippability
4 fully non-Cr systems down-selected; standard flexibility, standard pigments, and Skydrol resistance

3. Current Status Test Type of Testing Status Notes
Beach Exposure of Lap Joint Panels (aluminum & steel galvanic couples)
Integration
In Progress
9 fully non-Cr systems tested against Cr-primers and Zn-rich primers; Corrosion resistance and adhesion
Stress Corrosion Cracking Behavior of Non-Cr Systems
10 systems tested, including a Cr-containing control and a negative control
MIL-PRF Qual Testing for Semigloss Topcoat Systems for AGE
Qualification
4 Mg-rich coating systems with Fed-Std Color in various cure packages for AGE

4. Background: MIL-PRF-32239 Coating Systems
Complete
Pretreatment
Primer
Topcoat
Pantheon PreKote
Akzo Nobel Aerodur Mg-Rich Primer
PPG/Deft ELT 99-Series MIL-PRF Type IV
Akzo Nobel Aerodur MIL-PRF Type IV
3M AC131 (Boegel)
PPG EAP9
PPG CA7236 Mg-Oxide Primer
PPG CA MIL-PRF Type IV
AFMC memorandum (22 May 2014) citing that these systems have met the qualification requirements of MIL-PRF
In MIL-PRF-32239A, Type 4, Class 1, Grade 1 (Fully Non-Cr, standard flexibility, standard pigment)

5. Addt’l Non-Cr Testing Drying Time & Repairability
Complete
Pretreatment
Primer
Topcoat
Notes
Pantheon PreKote
Akzo Nobel Aerodur 2111P001 Mg-Oxide Primer
Akzo Nobel Aerodur 5000 MIL-PRF Type IV
1,3,4
Henkel Alodine 5200
Hentzen GEP / CEH Epoxy Primer
Hentzen APX / CMU
1,2,3
Notes: Key Drying Time, Adhesion, and Repairabilty Testing
(1) Tested for Drying Time at various Temperature/Humidity Combinations and Good Adhesion at 77/50, 90/10, and 90/90
(2) Tested for Drying Time at various Temperature/Humidity Combinations and Good Adhesion at 60/20
(3) Compatible with PreKote + Deft 02Y040 + MIL-PRF in Repairability
(4) Compatible with 3M AC AN 10P PPG CA9311 in Repairability

6. Addt’l Non-Cr Testing: Drying Time & Repairability
Complete
Temperature/Humidity Testing: Cure Time and Adhesion
Coating System
EnCon (Good Adhesion after 12 h)
System ID
Panel ID
Pretreat
Primer
Topcoat
77/50
90/10
90/90
60/20
60/90 1 A
PreKote
AN 2100P004 Mg-Rich
AN Aerodur
Yes No 2 B
PPG/Deft 99GY001 4 I
Alodine
Hentzen 53055
Hentzen 35515 7 K
AN 2111P001 MgO 12 L
PPG CA MgO
PPG CA9311
Control G
PPG/Deft 02Y040

7. Addt’l Non-Cr Testing: Drying Time & Repairability
Complete
Temperature/Humidity Testing: Cure Time and Adhesion
Panel ID
Chromate System
Chromate-Free Repair System
Delta E, Post Repair and UV
Pretreat
Primer
Topcoat
Pretreat Repair
Primer Repair
Topcoat Repair A
PreKote Deft 02Y40 Deft 99GY001
PreKote
Akzo 2100P004 Mg
Akzo Aerodur 5000
0.91
0.68
0.71 B
Deft 99GY001
0.44
0.34
0.33 K
Akzo 2111P001 MgO
0.85
0.76
0.89 G
Deft 02Y40
0.43
0.55
0.52 I
Alodine 5200
Hentzen GEP
Hentzen APX
0.79
0.64
0.60 L
PPG CA7236 MgO
PPG CA9311
0.58
0.86
3M AC-131 (Boegel) Akzo Nobel 10P PPG CA9311
0.45
0.48
0.41
1.08
0.77
0.42
0.47
EAP#9 PPG CA7236 (MgO) PPG CA9311
0.62
0.74
0.72
0.70
0.66
0.53
3M AC-131 (Boegel) Akzo 2100P004 (Mg-rich, Red) Akzo Aerodur 5000
0.83
0.69
0.49

8. Sealant Paintability (AS-5127/1): Mg-rich and Cr control Coating Systems
Complete
Substrate / Pretreatment
Sealants (one per sample set)
Pretreatment
Primer
Topcoat
AA7075-T6 Bare
Surface wipe w/ MEK followed by DeOX
PPG P/S 870, Class A 3M AC-735, Class B
PPG PR-1775, Class B
3M AC 730, Class B
PPG PR 1436 G (sprayable)
Pantheon PreKote
Akzo Nobel Aerodur 2100P004 Mg-Rich Primer
PPG/Deft 99-GY-001 MIL-PRF Type IV
Henkel Alodine 1600
PPG/Deft 02-Y-040 MIL-PRF-23377, Type 1, Class C
Notes: Testing requested to determine paintability of new sealant applied to OML
Sealant applied per product data sheet
Pretreatment/primer/topcoat applied and cured 14-days at ambient laboratory conditions
Wet tape adhesion testing performed; All systems at 4A or 5A – Report in progress

9. PATTI & Wet Tape Adhesion of Mg-Rich Ctg Sys Applied at Various Temps/Humidities
In Progress
Pretreatment
Primer
Topcoat
Pantheon PreKote
Akzo Nobel Aerodur 2100P004 Mg-Rich
Akzo Nobel Aerodur MIL-PRF Type IV
PPG/Deft 99-GY-001 MIL-PRF Type IV
Akzo Nobel Aerodur 2111P001 Mg-Oxide
PPG CA7236 Mg-Oxide
PPG CA MIL-PRF Type IV
EnCon #
Target Temp (°F)
Target RH 1 77 50 2 90 10 3 4 60 5 20
Notes: Testing requested to determine if there is an adhesion debit if the coating systems are applied at various temperature and humidity conditions (i.e., Environmental Conditions or EnCons)
Data collection completed; Data analysis in progress

10. Skydrol Resistant Coating Systems Testing to MIL-PRF-32239
In Progress
Pretreatment
Primer
Topcoat
Notes
3M AC-131 (Boegel)
Akzo Nobel LV2118 (Non-Cr)
Akzo Nobel Aerodur MIL-PRF Type IV
Removable with AS5050 & Sea2Sky 909;
Good corrosion resistance
Akzo Nobel Aerodur 2111P001 Mg-Oxide
PPG CA MIL-PRF Type IV
Removable with AS5050, E-3000M, & Sea2Sky Minor corrosion at 8 months on one sample
3M AC131 (Boegel)
Akzo Nobel XP (Non-Cr)
Removable with AS5050, E-3000M, & Sea2Sky; Good corrosion resistance
PPG EAP9
Akzo Nobel XP (Non-Cr)
Removable with AS5050 & Sea2Sky 909; Good corrosion resistance
Notes: Three chemical strippers work well on the coatings (1) AS5050 (2) E-3000M (3) Sea2Sky 909
15 Months Outdoor Exposure Testing ongoing at the Daytona Beach site operated by Battelle Memorial Institute --- Testing ECD March 2017

11. Skydrol Resistant Coating Systems Testing to MIL-PRF-32239: 8 mos Outdoor Exposure
In Progress
AA2024-T3 Bare
Beach Corrosion Testing
1 x 6 inch; Ti or Cd-plated steel fasteners
Outdoor Aging
12 x 12 inch panels
Schedule
Start: 4 December 2015
Inspections
12 April 2016
19 July 2016*
10 January 2017
*One of the Ti-Fasteners with Blistering; AC131 + AN 2111P001 MgO + AE5000 after 8 months

12. Skydrol Resistant Ctg Sys: Chem Strip Eval Artificial Aging w/ & w/o Recoat
In Progress
3-Step Process 2 1 3
Scuff-Sanded & Recoated
Process repeated to generate 3 layers of aged and reapplied coating
Coated Panels (4x8 ft) 210 °F, 96 h
8 Panels: prepared by aging, scuff/recoat x3
8 Panels: prepared by aging only (single application)

13. Skydrol Resistant Ctg Sys: Chem Strip Eval Artificial Aging w/ & w/o Recoat
In Progress ID
Chemical Removers 1
Aero Solutions AS 5050 Benzyl Alcohol & Hydrogen Peroxide Paint Stripper 2
CEE BEE E-3000M Hydrogen Peroxide Based Paint Stripper, Conforms to Tinker Purchase Description 3
Sea2Sky 909 Neutral Surface Preparation Compound; Boeing D Rev N 4
PPG RW5555 Benzyl Alcohol & Hydrogen Peroxide Paint Stripper 5
B&B Tritech 9095 Hydrogen Peroxide Paint Stripper; Boeing D Rev R; Tinker Purchase Description

14. Skydrol Resistant Ctg Sys: Preliminary Results
Close (≥90% Topcoat and ≥70% Primer) or Passed (≥90% Total)
System
Artificially- Aged
AS 5050
E-3000M
Sea2Sky 909
PPG RW5555
B&B 9095 A
Boegel CA7502 (MgO) CA9311
Heat Age/Scuff/Recoat
Close (100/70)
Failed (5/5)
Failed (50/5)
Failed (90/5)
Heat-aged only
Failed (50/50)
Failed (0/0)
Passed (90/90)
Failed (10/10) B
Boegel AE2111 (MgO) AE5000
Failed (100/50)
Passed (100/80)
Failed (90/30)
Passed (100/100)
Failed (100/60)
Failed (70/10)
Failed (90/50) C
Boegel AN LV2118 (NCr) AE5000
Close (90/80)
Failed (70/60) D
Boegel AE2111 (MgO) CA9311
Passed (100/90)
Failed (70/30)
Failed (80/60)
Close (100/80) E
Boegel AN LV2118 (NCr) CA9311
Failed (80/15)
Failed (90/60)
Failed (90/10) F
PreKote Deft 02Y040 (Cr) Deft 99GY001
Failed (100/5)
Failed (100/20)
Failed (100/0) G
Boegel AN XP CA9311
Failed (100/10) H
Boegel AN XP CA9311
Failed (80/30)

15. Beach Corrosion Fastener Panels
Beach Exposure of Aluminum & Steel Fastener & Galvanic Coupled Lap Joints
In Progress
Test
Description
Substrates
Beach Corrosion Fastener Panels
1x6-inch Flat Panels with either: Three (3) Aluminum Rivets; Three (3) Cadmium Plated Screws; or Three (3) Stainless Screws (all fasteners are dry-installed) Fasteners panels will be assembled --Then substrate will be either (1) media-blasted or (2) pretreated; --Then panels will be coated
AA6061-T6, 0.25-inch thick DOMEX, 0.25-inch thick A36, 0.25-inch thick MIL-A Class 2, 0.25-inch thick AA7075-T73511, 0.25-inch thick

16. Beach Corrosion Lap-Joint Panels
Beach Exposure of Aluminum & Steel Fastener & Galvanic Coupled Lap Joints
In Progress
Test
Description
Substrates
Beach Corrosion Lap-Joint Panels
4x4-inch Flat Panels of Galvanic Couples, Attached using aluminum fasteners
--Lap-Joints will be assembled --Then substrate will be either (1) media-blasted or (2) pretreated; --Then lap-joints will be coated
AA6061-T6, 0.25-inch thick DOMEX, 0.25-inch thick
AA6061-T6, 0.25-inch thick A36, 0.25-inch thick
AA6061-T6, 0.25-inch thick MIL-A Class 2, 0.25-inch thick AA7075-T73511, 0.25-inch thick
A36, 0.25-inch thick
100 deg countersink
4-inch
1-inch
2-inch
4-inch
1-inch
4-inch

17. Quickstrip G 10/20 Media blast & solvent wipe (MIL-T-81772 thinner)
Beach Exposure of Aluminum & Steel Fastener & Galvanic Coupled Lap Joints
In Progress
Coating Systems For Steel Surfaces and Steel/Aluminum Lap Joint Sample Surfaces
Pretreatment
Primer
Topcoat
Quickstrip G 10/20 Media blast & solvent wipe (MIL-T thinner)
Akzo Nobel 10P3-2 Zn-Rich MIL-PRF-26915
PPG/Deft 99W009 Color MIL-PRF Type IV
PPG/Deft 02Y040 Cr Epoxy MIL-PRF Type 1 Class C2
NCP N-8959 B/A MIL-DTL Type IV
Akzo Nobel 2100P004 Mg-Rich
Navy & Randolph Coatings Al-Rich LN4847
Akzo Nobel Mg-rich Experimental Isocyanate cure system

18. Beach Exposure of Aluminum & Steel Fastener & Galvanic Coupled Lap Joints
In Progress
Coating Systems For Aluminum Surfaces
Pretreatment
Primer
Topcoat
Pantheon PreKote
Akzo Nobel 2100P004 Mg-Rich
PPG/Deft 99W009 Color MIL-PRF Type IV
Navy & Randolph Coatings Al-Rich LN4847
Henkel Alodine 1600
NCP N-8959 B/A MIL-DTL Type IV
Henkel Alodine 5200
Scrub & DeOX
PPG/Deft 02Y040 Cr Epoxy MIL-PRF Type 1 Class C2
PPG/Deft 03W127 Color MIL-PRF Type I

19. Stress Corrosion Cracking Resistance of Non-Cr Coating Systems
In Progress
Pretreatment
Primer
Topcoat
Pantheon PreKote
Akzo Nobel Epoxy (Negative Control)
PPG/Deft ELT 99-Series (MIL-PRF Type IV)
Akzo Nobel Aerodur 2100 Mg-Rich Primer
PPG/Deft Rare Earth Conv Coat
PPG/Deft Rare Earth (cocktail) 02-GN-093 Epoxy Primer
PPG EAP9
PPG CA7236 Mg-Oxide Primer
PPG CA (MIL-PRF Type IV)
Akzo Nobel XP (Experimental Non-Cr)
No Pretreatment (IPA wipe only)
PPG/Deft 44-GN-098 (MIL-PRF-85582)
Akzo Nobel 24-F (Boeing DMS 2143, Type 1, Class 1)
Deft Advanced Multifunctional Self-Priming Topcoat (97-GY-160)
Henkel Alodine 5200
Hentzen GEP / CEH Epoxy Primer
Hentzen APX / CMU

20. Stress Corrosion Cracking Samples
In Progress
ASTM G 49
Load to 65% Tensile Yield Strength
Alternate Immersion Test – 1hr Cycle
10 min – 3.5% NaCl solution
50 min – Ambient air
1000 hrs or Failure
Substrates: (53 HRC/280 ksi UTS) and 7075-T6
ASTM G49 Standard Practice for Preparation and Use of Direct Tension Stress-Corrosion Test Specimens
Prior Exposure
Simulated damage: Uncoated band (not mechanically damaged)

21. MIL-PRF-32239 Qual Testing of Semigloss Topcoat Systems for AGE
In Progress
Pretreatment
Primer
Topcoat
Pantheon PreKote
Akzo Nobel 2100P004 Mg-Rich
PPG CA9321 Color MIL-PRF Type IV
Akzo Nobel Aerodur 5000 Color MIL-PRF Type IV
PPG/Deft 99GY071 Color MIL-PRF Type IV
PPG CA 9311 Color MIL-PRF Type IV
PPG/Deft 02Y040 MIL-PRF-23377, Type 1, Class 2
Full qualification testing in progress for Aerospace Ground Equipment (AGE)