290 likes | 668 Views
Field Touchup/Repair of Powder Coatings. Air Force Inventory Of OEM Powder Coated Equipment Continues to Increase Influence of success in commercial applications Performance Cost Environmental ComplianceAF Depot Level Powder Coating Capabilities Are Emerging Hill AFB Robins AFB Tinker AFB Others.
E N D
1. Field Touchup/Repair of Powder Coatings 2003 Air Force Corrosion Program Conference
March 10 – 14, 2003
Dr. Douglas Neale
NCI Information Systems, Inc.
Mr. David Ellicks
Air Force Corrosion Prevention and Control Office
Robins AFB, Georgia
2. Field Touchup/Repair of Powder Coatings Air Force Inventory Of OEM Powder Coated Equipment Continues to Increase
Influence of success in commercial applications
Performance
Cost
Environmental Compliance
AF Depot Level Powder Coating Capabilities Are Emerging
Hill AFB
Robins AFB
Tinker AFB
Others
3. Field Touchup/Repair of Powder Coatings Powder Coatings Encountered
Thermosets – polymer powders applied electrostatically and baked (250oF – 450oF)
Classes of powder chemistries for AF applications
Epoxy – very good physical/chemical performance for
interior use (UV-sensitive)
Polyesters – very good physical/chemical performance for
interior/exterior use
TGIC
Urethanes
Selection based on performance requirements and application characteristics of the coating
4. Field Touchup/Repair of Powder Coatings How to Repair When Flawed or Damaged?
Requirements/expectations (depot and field)
Repair process practicability
Compatibility with existing powder coating
Performance – mechanical, chemical and
corrosion resistance (durability)
Appearance
Production/depot sites
Strip and re-coat entire part
Touch-up (original process, aerosols, brush kits)
Field sites
Original process not practical
Touch-up with available military/commercial materials
5. Field Touchup/Repair of Powder Coatings Project Purpose: Develop Experience Base with Materials/Techniques for Field Repair of Damaged Powder Coatings
Cleaning/preparation
Coating materials
Commonly available military/commercial products
Innovative
Application processes
6. Field Touchup/Repair of Powder Coatings Project Elements
Lab - relative corrosion performance screening
Select common touch-up/repair coating materials
Select simple application process/technique
Evaluate relative corrosion performance
Modified Q-Fog CCT-1 (common automotive standard)
Cyclical corrosion
4 hrs salt fog, 2 hours dry-off, 2 hours humidity
Down-select
Field
Environmental exposure of repaired coupons
Florida Coastal
Repair damaged support equipment
7. Field Touchup/Repair of Powder Coatings Laboratory Screening Tests
Powder coating materials selected
Epoxy
Polyester TGIC
Urethane polyester
Substrates – clean
Aluminum – no pretreatment
Steel – iron phosphate “Bonderite” pretreatment
Coupons supplied/prepared by commercial vendors
Morton (Rohm & Haas)
Sherwin Williams
8. Field Touchup/Repair of Powder Coatings Laboratory Screening Tests (continued)
Repair materials
Common MILSPEC primers/tie-coats/topcoats
Commercial topical pretreatments/VCI coatings
UV-cured topcoats
Direct-to-metal waterborne acrylic latex topcoats
Urethane protective barrier tape
9. Field Touchup/Repair of Powder Coatings Laboratory Screening Tests – Repair Materials
Solventborne primer / high solids topcoat
Baseline: -23377, Type 1, Class C / - 85285, Type II
-23377, Type 1, Class N / -85285, Type II
Waterborne primer / high solids topcoat
-85582, Type I, Class C2 / -85285, Type II
Pretreat / high solids topcoat (-85285, Type II)
Alodine 1132
Sanchem Safegard 6100C or 13150A
T.O. 1-1-8 non-chromated epoxy tie coat
Cortec VCI 386
10. Field Touchup/Repair of Powder Coatings Lab Screening Tests – Materials (cont.)
Solvent-borne primer / water reducible topcoat
-23377, Type 1, Class C /- 64159, Type II (Army CARC)
-23377, Type 1, Class N / -64159, Type II (Army CARC)
Waterborne primer / water reducible topcoat
-85582, Type I, Class C2 / -64159, Type II (Army CARC)
Pretreat / water reducible topcoat (-64159, Type II)
Alodine 1132
Sanchem Safegard 6100C or 13150A
T.O. 1-1-8 non-chromated epoxy tie coat
Cortec VCI 386
11. Field Touchup/Repair of Powder Coatings Lab Screening Tests – Materials (cont.)
Single coat
Cortec VCI 386
UV-cure coatings (2 manufacturers)
Stand-alone (no primer or pretreat)
Over Alodine 1132 pretreatment
Over Sanchem Safegard 6100C or 13150A
Over Cortec VCI 386
12. Field Touchup/Repair of Powder Coatings Lab Screening Tests – Materials (cont.)
Direct to metal acrylic latex (DTM)
Stand alone (no pretreat)
Over Alodine 1132
Over Sanchem Safegard 6100C or 13150A
Over Cortec VCI 386
3M 8681 HS polyurethane tape over pretreat
Alodine 1132
Sanchem Safegard 6100C or 13150A
Cortec VCI 386
13. Field Touchup/Repair of Powder Coatings Auxiliary Touch-up Coating Development
Corrosion Office initiative
Powders dissolved directly in environmentally compliant solvents (acetone, PCBTF)
Brush/aerosol application of coating with matched chemistry
Local thermal cure (heat gun, IR lamp)
Coating produced, properties under investigation
14. Field Touchup/Repair of Powder Coatings Lab Screening Tests - Coupon Preparation
Powder coating removal in center band (PMB)
Roughen bare metal and adjacent powder coating with polymer abrasive pad
Isopropyl alcohol wipe
Brush application of primer/pretreat and topcoat
15. Field Touchup/Repair of Powder Coatings Lab Results – General
640 hours – 80 cycles, Modified CCT
All Touch-Up Coatings Proved Chemically and Physically Compatible with Substrates/Powder Coatings Evaluated
Abrasive Pad/Alcohol Wipe Provided Suitable Surface Prep (Coating and Substrate)
Brush/”Sempen” Used for All Coating Application (Cosmetics Not Optimum)
See Final Tech Report for Detailed Analysis
16. Field Touchup/Repair of Powder Coatings Lab Results – Quantitative Evaluation of Coating Systems Used for Repair
Numerical Composite Rating of Performance
Creepage
General Corrosion
Blisters
MILSPEC Baseline Comparison: -23377 / -85285
17. Field Touchup/Repair of Powder Coatings
18. Field Touchup/Repair of Powder Coatings Field Tests
Down-selected Candidates from Original Matrix
New Coatings Identified After Start of Lab Tests
Battelle Florida East Coast Test Site
Repaired “Damaged” Coatings on Coupons
6 Month Exposure
Evaluate Performance (Visual – Quantitative)
Corrosion penetration, creepage
Blisters
Coating appearance
Test Analysis/Report Due in March, 2003
19. Field Touchup/Repair of Powder Coatings Field Tests - Down-Selection from Original Matrix
1: -23377 Type I, Class C / -85285 Type II
2: -23377 Type I, Class N / -85285 Type II
3: -85582 Type I, Class C2 / -85285 Type II
8: -23377 Type I, Class C / -64159 Type II
9: -23377 Type I, Class N / -64159 Type II
10: -85582 Type I, Class C2 / -64159 Type II
15: VCI, Single Coat
24: Alodine / HS Polyurethane Tape
26: VCI / HS Polyurethane Tape
28: Alodine / Water-Borne DTM Acrylic Latex
30: VCI / Water-Borne DTM Acrylic Latex
20. Field Touchup/Repair of Powder Coatings Field Tests - Added Coating Systems
T1: DTM Acrylic Latex Primer / DTM Acrylic Latex Topcoat
T2: DTM Acrylic Latex Topcoat (Two Coats, No Primer)
T-3A: “Zero Rust” Primer (Aerosol)
T-3B: “So Sure” (Aerosol)
UV: UV Cured Liquid Applied at Manufacturer Facility
Z: -23377 Type I, Class N / -85285 Type III
( 50 mg/l VOC)
21. Field Touchup/Repair of Powder Coatings “Damaged” Test Coupon Configuration
22. Field Touchup/Repair of Powder Coatings Field Test Results - Aluminum
23. Field Touchup/Repair of Powder Coatings Field Test Results - Steel
26. Field Touchup/Repair of Powder Coatings Conclusions – Lab and Field
All coatings used for touch-up were chemically and physically compatible with the powder coatings
Scuff sanding and alcohol wipe provide good bonds
Multi-component MILSPEC paint systems provide best performance – available in small touch-up kits for field
Non-chromated MILSPEC primers generally performed as well as chromated under MILSPEC topcoats
HS polyurethane tape provides excellent protection
UV cured liquid technology not ready for field
Innovative powder/solvent not viable
Powder coatings are not magic - current touch-up/repair procedures and techniques apply for powder coatings
27. Field Touchup/Repair of Powder Coatings Questions?
28. MOPAF
29. MOPAF
30. MOPAF PRAM PROJECT:
TWO YEARS: SEPT 01 -? SEPT 03
PURPOSE:
ACCELERATE IMPLEMENTATION OF POWDER COATING
TECHNOLOGY INTO AIR FORCE MAINTENANCE ACTIVITY
DEMONSTRATE CAPABILITY ON MAJOR PRODUCTION
COATED COMPONENTS/EQUIPMENT
PROMOTE ENVIRONMENTAL COMPLIANCE –
REDUCE/ELIMINATE HAZMATS, VOCS, HAZWASTES
31. MOPAF PROJECT ELEMENTS:
SURVEY/SELECT CANDIDATE PROCESS/STAKEHOLDER
OGDEN ALC - PRIMARY
OKLAHOMA CITY ALC - SUPPORT
VALIDATE POWDER COATING PROCESS ON CANDIDATE APPLICATION
AIRCRAFT WHEELS
LANDING GEAR COMPONENTS
DESIGN/BUILD/VALIDATE MODULAR FACILITY
IN PROGRESS
IMPLEMENT MODULAR FACILITY AT STAKEHOLDER SITE
SUMMER-FALL 2003
32. MOPAF PROCESS VALIDATION:
MATERIALS:
T-38 WHEELS - 2024 ALUMINUM ALLOY
LANDING GEAR COMPONENTS
7000 SERIES ALUMINUM ALLOY (ACTUATOR)
4340 HS STEEL (STRUT - 260 KSI)
COATING SYSTEMS – COMPARATIVE PERFORMANCE TESTING
SURFACE PREP
WHEELS – ANODIZED, PEENED/ANODIZED
LANDING GEAR ALUMINUM – ANODIZED
LANDING GEAR STEEL – CAD PLATE, IVD ALUMINUM
BASELINE: -85582 TYPE I CLASS C2 / -85285 TYPE I
POWDER – TGIC POLYESTER (275OF CURE)
SINGLE COAT
-85582 PRIMER / P0WDER
33. MOPAF COMPARATIVE COATING PERFORMANCE TESTS
CORROSION: CCT, FILIFORM, B-117
TENSILE STRENGTH (ALUMINUM) – 5 BAKE CYCLES
FATIGUE (ALUMINUM) – 5 BAKE CYCLES
HYDRAULIC FLUID IMMERSION – 3 FLUIDS
GRAVELOMETER IMPACT – @ ROOM, LOW TEMPERATURE
TEMPERATURE SHOCK
ABRASIVE RESISTANCE
CLEANABILITY
STRIPABILITY
34. MOPAF EQUIPMENT SYSTEM DEVELOPMENT
DESIGN
BUILD PROTOTYPE
DELIVER/ASSEMBLE HILL AFB*
FAMILIARIZE AF MAINTENANCE PERSONNEL
OPERATION/MAINTENANCE
START- UP/VALIDATION
INITIATE PRODUCTION OPERATION
* FIRST ASSIGNMENT CONTINGENT ON SUCCESSFUL COATING PERFORMANCE TESTS
37. MOPAF CURRENT STATUS
MOPAF CONSTRUCTION
MARCH 2003 COMPLETION
COMPARATIVE COATING PERFORMANCE TESTS
(@ CTIO)
SPECIMEN PREPARATION: INITIATE MARCH 2003
CONDUCT TESTS: JUNE - AUGUST 2003 (ESTIMATE)
38. MOPAF REVIEW:
VERSATILE/TRANSPORTABLE MODULAR POWDER, CONVENTIONAL COATING APPLICATION FACILITY
STAND-ALONE OPERATION AT A DEPOT OR FIELD SITE
INSTALLATION WILL NOT DISRUPT EXISTING PRODUCTION OPERATIONS
PROCESS VALIDATION PRIOR TO COMMITTMENT TO POWDER TECHNOLOGY INTEGRATION OR CHANGEOVER
PRODUCTION USE DURING INTEGRATION/CHANGEOVER
39. MOPAF QUESTIONS ??