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NAVSEA Basic Paint Inspector Training: Introduction
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Introduction
NBPI Course Developed by Naval Surface Warfare Center, Carderock Division Code 614 under direction of
NAVSEA 05M1
NAVSEA Basic Paint Inspector Course (NBPI)
Topics
l Certified paint inspector duties
l Formal inspection responsibilities
l Course objectives
Scope
l This unit provides an overview of the NAVSEA Basic Paint Inspector Course and the course learning objectives.
Learning Outcomes
l Plan the job
l Recognize chain of authority (Technical Authority)
l Appreciate coatings assessment
l Select surface preparation methods and proper coatings
l Measure environmental conditions
l Evaluate newly painted surfaces
Learning Outcomes (cont.)
l Appreciate the practical aspects of the preservation process
l Identify health and safety precautions
l Locate preservation information
Duties of Inspector
l Formal inspections
l Assist Naval activities regarding coatings QA
l Train ship’s force
NAVSEA Basic Paint Inspector Training: Introduction
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Responsibilities of Inspector
l Pre-job meeting l Affirm proper safety practices l Inspect surface preparation l Check paint in can l Ensure proper application l Measure coating thickness l Observe, assess, document, report results
Coatings and Surfaces to be Protected
l Will be discussed throughout the program
Why Course Developed?
l Extend coating service life to – Reduce maintenance
– Reduce hazardous waste
l Trained personnel needed to implement NSTM 631 and 009-32 QA requirements
Skills Learned
l Steps needed to do quality surface preparation and application l Recognize Technical Authority l Recognize Decision Tree for Departures from Specifications
(Appendix J) l Appreciate coatings assessment l Select proper surface preparation methods and coating
materials l Use available tools to perform inspections and tests l Evaluate applications l Recommend corrective actions l Basic safety l Identify sources of information
Course Outline
1. Introduction 2. Corrosion 3. Corrosion Control 4. NAVSEA Documents 5. Non-Physical Contact Cleaning Methods 6. Mechanical Cleaning Methods 7. Abrasive Blast Cleaning 8. Waterjetting 9. Surface Preparation Method Selection 10. Coatings
Course Outline (cont’d.)
11. Safety 12. Coating Application 13. Coating Defects and Failures 14. Specialty Coatings/Surfaces 15. Coating Inspector Preparation 16. Condition Assessment 17. Nonskid 18. Daily Instrument and Inspection Workshops and
Exercises
NAVSEA Basic Paint Inspector Training: Introduction
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Housekeeping Issues
l Course schedule l Course materials
l Discussions/workshops l Breaks/lunches l Facilities
l Emergency evacuation route
Housekeeping Issues
l Review the daily schedule
l Be prompt for class
l Turn off cell phones and electronic devices
l Please do not smoke in class
Introduction
l Instructors: Who we are, What we do
l Students: Who you are, What you do – Any Prior Coatings QA Experience?
l Description of course materials
Why QA?
l Provide best quality preservation to protect Navy assets
l Required by 009-32, NSTM Chapter 631, PPIs, and the Submarine Maintenance Standard for many coated areas
l May be required by Command
What are critical coated areas?
l From NAVSEA Standard Item 009-32: – MK41 VLS launcher top and base – Underwater hull surfaces (including appendages and
surfaces below the water-line up to and including the boottopping)
– Cofferdams – Hangar, flight, catapult, and vertical replenishment
decks – CVN flight deck landing areas – RAST track trough (including sumps) – Well deck overheads
What are critical coated areas? (cont’d.)
– Bilges (including sumps) – Interior surfaces of intake vent plenums, defined as combustion
air intakes (gas turbine, diesel, and steam) and other vent system intake plenums with openings greater than 7 square feet
– Uptake spaces – Gas turbine exhaust uptake spaces and trunks – Tanks (including sumps) – Voids – All recesses on submarines below the upper boottop – Interior surfaces of submarine sail (fairwater) and superstructure – Aircraft launch and recovery equipment – Arresting gear sheave foundations
NAVSEA Basic Paint Inspector Training: Introduction
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NBPI Course Format
l Lecture and discussions l Demonstrations and workshops
l NBPI Course Written Final Exam (closed book) l NBPI Course Practical Instrument Exam (closed book) l NPBI Specification Navigation Exam (open book)
Certification Process
l Pass NBPI Course (80% or better on each component)
l Document 2 years marine coatings experience
Work Experience
l Work experience must be in one or more of the following areas: – Inspection of Coating Application on Navy, Coast
Guard or similar vessel – Repairs, Surface Preparation and Application of
marine coatings on Navy, Coast Guard or similar vessel
– Project Management of Coatings Projects on Navy, Coast Guard or similar vessel
Work Experience (cont’d.)
– Coating Specification and/or Contract Development on Navy, Coast Guard or similar vessel
– Coating Equipment and Material Supplier Technical
– Representative on Navy, Coast Guard or similar vessel
– Failure Analysis of Coating on Navy, Coast Guard or similar vessel
Recertification
l Maintained for 4 years
l Take an open book refresher exam online
l Pass with 85%
l NBPI Recertification full details online (http://www.sspc.org/training/nbpi_recert.html)
Certification
**All individuals who have been certified prior to the implementation of the new certification program will retain their certification status until their next scheduled certification renewal date.**
NAVSEA Basic Paint Inspector Training: Introduction
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Disciplinary Action Criteria (DAC) Read Carefully
l Warning
l Probation
l Suspension
l Revocation
**Disciplinary actions could result in suspension or revocation of certification**
Team Exercises
l Important – Function as team l Make teams – Choose team name l Develop list of top 10 things your team
wants to learn or get out of this course l Flip charts – 5 minute presentation to group
– choose a spokesman
Professional Societies and Organizations
l SSPC: The Society for Protective Coatings (previously Steel Structures Painting Council)
l ASTM International (previously American Society for Testing and Materials)
l ISO – International Organization for Standardization
l NACE International (previously National Association of Corrosion Engineers)
NAVSEA Basic Paint Inspector Training: Corrosion
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Corrosion
NAVSEA Basic Paint Inspector Training!
Topics
l Components necessary for corrosion
l The galvanic series and galvanic corrosion
l Common types of corrosion on ships
l Environmental factors that contribute to corrosion
Scope
l Acquaints students with the basic principles of corrosion, especially those that occur most frequently on Navy ships
Learning Outcomes
l Identify the basic principles of corrosion
l Recognize the different types of corrosion most likely to occur on ships
l Discuss the environmental factors that accelerate corrosion and the most corrosive areas on ships
What Is Corrosion?
l Definition: – Deterioration of any material due to reaction
with the environment in contact with the material that results in loss of the material and its properties (e.g., loss of steel).
Cost of Corrosion!!
l Estimated annual cost of corrosion – $276 billion in all US
– $1 billion for Navy
– $250 million for ship tanks and voids
NAVSEA Basic Paint Inspector Training: Corrosion
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“Environment” Meanings
l What does term “environment” mean to a coating or metal with respect to corrosion? – It’s not like our natural environment, such as the earth,
air, and water… – It means the physical & chemical conditions they are
exposed to, such as salts, temperature, acids, ozone, etc.
l Different environments have different effects on different materials.
Corrosion Cycle
Corrosion Cell Components
ACME Memory Trick
Anode
Cathode
Metallic Pathway
Electrolyte
Electrochemical Potential
l Measured in voltage, and is a basic property of all metals & alloys.
l Electrical current (electrons) flow from high potential areas to low potential areas.
l High potential = more prone to corrosion = “active” metals.
l Low potential = less prone to corrosion = “noble” metals.
Dry Cell Battery Electrolytic Cell
Electron Flow!
Ionic Dissolution
Seawater Electrolyte
Fe++!
Stee
l:Ano
de!
Bro
nze:
Cat
hode!
External Circuit
NAVSEA Basic Paint Inspector Training: Corrosion
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Electrolytic Cell
Electron Flow
Ionic Dissolution
Seawater Electrolyte
Stee
l:Cat
hode
Bro
nze:
Cat
hode
Zin
c:A
node
Zn++ Zn++
External Circuit
Where’s the bronze?
Unpainted bronze ship propellers provide a large area for galvanic coupling.
General Corrosion
Minute differences between individual grains leads to anode/cathode pairs and general corrosion.
Typical “grain” structure of metal
Corrosion Cell A Picture is Worth a Thousand Words
Anode Cathode pairs in steel continue to be active over time
See how steel will waste away
NAVSEA Basic Paint Inspector Training: Corrosion
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Corrosion cells can continue right through to the other side
There’s usually more corrosion than 1st meets the eye
Corrosion Cells work inside the steel and under the preservation
Sometimes it’s discovered too late.
Galvanic Series in Seawater
Magnesium Alloys Zinc Aluminum Alloys Cadmium Steel or Iron 18-8 Stainless; Active Brass Bronze Copper Nickel Alloys Nickel Inconel 18-8 Stainless; Passive Titanium Alloys Platinum Graphite
More likely to corrode (Anodic)
Less likely to corrode (Cathodic)
Types of Corrosion
l Corrosion does not always look the same or occur for the same reasons
l The appearance of corrosion is primarily affected by: – Environment – Materials of construction – Configuration
l Many forms of corrosion occur together.
No Corrosion
NAVSEA Basic Paint Inspector Training: Corrosion
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Uniform Corrosion Uniform Corrosion
USS ANONYMOUS Fan Room!
Dissimilar Metal
Dissimilar Metal Embedded in Aluminum Creates Corrosion Cell
Dissimilar Metal
Brass shock mounts for light on aluminum mount.
Pitting Pitting
Severe pitting of 410 stainless steel.
NAVSEA Basic Paint Inspector Training: Corrosion
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Crevice Corrosion Crevice Corrosion
Aluminum alloy lap joint on an aircraft
Stress Corrosion Cracking Stress Corrosion Cracking
Chloride SCC of stainless steel
Failure Caused by Blast Embedded Particles Initiating Corrosion Intergranular
NAVSEA Basic Paint Inspector Training: Corrosion
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Intergranular
Intergranular corrosion of sensitized stainless steel
Exfoliation
Exfoliation
Aluminum alloy plate!
Exfoliation
Aluminum Grain Structure
Grains are flattened and elongated during rolling
of aluminum plate
General Corrosion
Environmental Effects
l Humidity/Oxygen
Corrosion of Underwater Hull!
Environmental Effects
l Humidity/Oxygen
l Salt Water
NAVSEA Basic Paint Inspector Training: Corrosion
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Corrosion of Battery Box Caused by Battery Acid
Environmental Effects
l Humidity/Oxygen
l Salt Water
l Chemicals
Environmental Effects
l Humidity/Oxygen
l Salt Water
l Chemicals
l Heat/Temperature
Corrosion of Steam Piping
Environmental Effects
l Humidity/Oxygen
l Salt Water
l Chemicals
l Heat/Temperature
l Stack Gases
Paint failure caused by stack gases, without protection area, will soon begin to corrode!
Environmental Effects
l Humidity/Oxygen
l Salt Water
l Chemicals
l Heat/Temperature
l Stack Gases
l UV Radiation Chalking of an epoxy topcoat—
eventually coating will fail allowing corrosion of substrate!
Open Forum
l What other conditions or items can be found on board ship that could contribute to corrosion or coating deterioration? – Examples:
• Decontaminating solutions • AFFF (Aqueous Film Forming Foam) • Biofouling • Smog and Acid Rain • CHT and Sanitary Tanks
Summary
l Corrosion continuously occurs everywhere.
l Different alloys and metals have different tendencies to corrode
l Corrosion is broken down into these types: – Uniform – Dissimilar metals – Pitting – Crevice – Stress cracking – Intergranular
l Environmental factors play a significant role in corrosion
NAVSEA Basic Paint Inspector Training: Corrosion Control
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Corrosion Control
NAVSEA Basic Paint Inspector Training!
Topics
l Three mechanisms of corrosion control by coatings (barrier, sacrificial, inhibitive)
l Sacrificial and impressed current cathodic protection systems
Scope
l Acquaints students with the basic mechanisms for controlling corrosion on Navy ships (coating and cathodic protection) and how they work well together
Learning Outcome
l Define the different mechanisms by which coatings control corrosion and the basic properties of coatings used for corrosion control
l Recognize the basic differences between sacrificial anode and impressed current cathodic protection for corrosion control
Corrosion Control
l Materials Selection
l Control Environment
l Design Details
Coatings to Prevent Corrosion
l Three primary ways coatings act to prevent corrosion on steel – Barrier Coatings
• e.g. epoxy – Sacrificial Primers
• e.g. inorganic zinc – Inhibitive Primers
• e.g. zinc molybdate
NAVSEA Basic Paint Inspector Training: Corrosion Control
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Barrier Coatings
l Requirement: – Reduced permeability to moisture and
oxygen • Both oxygen and moisture are required for corrosion
to occur • No coating is completely impermeable • Pigment selection can be important
Barrier Coatings
l Requirement: – Coating must adhere tightly to the
substrate with no breaks • If the coating adheres tightly, moisture
cannot get close enough to the surface to cause corrosion
• Breaks in the coating allow corrosion to begin very quickly
Barrier Coatings
l Requirement: – Resistance to the environment
• Coatings must withstand the environment in which they are used
• For example: – Chemical (ballast tank, fuel tank, CHT tank) – Abrasion (non-skid, deck coatings)
Sacrificial Primers
Steel Substrate: Cathode!Zinc Rich!
Coating!Anode!
Topcoat!
Water!Electrolyte!
In sacrificial primers, pigments provide active electrochemical protection by reacting with the
environment.!
Sacrificial Primers
l Must be used as the primer—needs to be in electrical contact with steel.
l Generally, need a high loading of zinc powder by weight. – Adjacent particles must be in contact for
effective protection.
– Inorganic binders are typically more effective than organic (e.g. epoxy) binders.
Class Input
l Name some other types of sacrificial coatings processes – Galvanizing (zinc) – Electroplating (zinc, cadmium) – Metal Spray Coatings (zinc, aluminum)
NAVSEA Basic Paint Inspector Training: Corrosion Control
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Inhibitive Primers
Substrate!
Moisture Penetration!
Inhibitive Primer!
Inhibitive coatings react with moisture absorbed by the topcoat to form products
which inhibit the corrosion process.!
Inhibitive Primers
l Must be used as primer coat—needs to be in contact with steel.
l Examples: – Red lead, lead oxide, lead chromate (Banned!) (form
inhibitive soaps)
– Zinc chromate, strontium chromate, chromate conversion coating (Phasing out!)
– Zinc molybdate (TT-P-645B)
Note: the latter two dissolve to place inhibitors in solution.
Cathodic Protection
l Protects metal by forcing entire surface to be the cathode of the overall electrochemical cell.
l ENTIRE surface to be protected MUST be immersed in the electrolyte.
l Two methods: – sacrificial anodes – impressed current cathodic protection
Sacrificial Anodes
l Entire exposed, submersed surface becomes the cathode
l Anodes made of a more active material than the substrate
l Examples: zinc, aluminum l Surface MUST be immersed
in electrolyte for sacrificial anodes to function
Sacrificial Anodes
The deterioration of the anode is indicative of a properly working anode.!
Sacrificial Anodes
In this photo, shipyard workers have nailed zinc anodes to wood docking blocks in an effort to prevent corrosion
of the steel strapping. Will this work?!
NAVSEA Basic Paint Inspector Training: Corrosion Control
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Sacrificial Anodes
l Zinc and Aluminum anodes “self-regulating”
l Magnesium anodes and impressed current systems not “self-regulating”
Sacrificial Anodes
This poor guy really thinks he has a relic from the American Revolution!
Cathodic Protection
Basic Impressed Current Cathodic Protection (ICCP) System!
Failed Dielectric Shield (called Capastic Shield in 009-32)
Rust bleed through a dielectric shield indicates cracks which penetrate to the hull
Failed Dielectric Shield
Note calcareous deposits at failure sites in dielectric shield!
ICCP Components
Properly Operating ICCP Anode With Dielectric Shield Bleaching (often called a “Flame” pattern)
NAVSEA Basic Paint Inspector Training: Corrosion Control
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Cathodic Protection
l Why paint the ship’s hull if it has cathodic protection? – Huge current demand—insufficient power supply
– Zinc anodes deplete rapidly—large area effect
– Antifouling needed to reduce drag friction
Cathodic Protection for Your Car
What’s missing?!
Summary
l Corrosion is controlled on Navy ships by barrier, sacrificial, and inhibitive coatings
l Sacrificial and impressed currents are two methods of cathodic protection
l Impressed current uses permanent (non-sacrificing) metal anodes
l Sacrificial anode protection attaches a more active metal to the structure