NAVSEA Basic Paint Inspector Training: Introduction. l Certified paint inspector duties. l Formal inspection responsibilities. l Course objectives

Transcription

1 NAVSEA Basic Paint Inspector Training: Introduction Introduction Topics NAVSEA Basic Paint Inspector Course (NBPI) l Certified paint inspector duties l Formal inspection responsibilities l Course objectives NBPI Course Developed by Naval Surface Warfare Center, Carderock Division Code 614 under direction of NAVSEA 05M1 Scope Learning Outcomes l This unit provides an overview of the NAVSEA Basic Paint Inspector Course and the course learning objectives. 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.) Duties of Inspector l Appreciate the practical aspects of the preservation process l Identify health and safety precautions l Locate preservation information l Formal inspections l Assist Naval activities regarding coatings QA l Train ship s force 1 1

2 NAVSEA Basic Paint Inspector Training: Introduction 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 Responsibilities of Inspector 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 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 Course Outline (cont d.) 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 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 1 2

3 NAVSEA Basic Paint Inspector Training: Introduction Housekeeping Issues Housekeeping Issues l Course schedule l Course materials l Discussions/workshops l Breaks/lunches l Facilities l Emergency evacuation route 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 Why QA? 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 l Provide best quality preservation to protect Navy assets l Required by , 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 : 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 1 3

4 NAVSEA Basic Paint Inspector Training: Introduction NBPI Course Format Certification Process 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) l Pass NBPI Course (80% or better on each component) l Document 2 years marine coatings experience Work Experience Work Experience (cont d.) 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 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 Certification l l Maintained for 4 years Take an open book refresher exam online l Pass with 85% l NBPI Recertification full details online ( **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.** 1 4

5 NAVSEA Basic Paint Inspector Training: Introduction l Warning l Probation l Suspension l Revocation Disciplinary Action Criteria (DAC) Read Carefully **Disciplinary actions could result in suspension or revocation of certification** l Important Function as team l Make teams Choose team name Team Exercises 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) 1 5

6 NAVSEA Basic Paint Inspector Training: Corrosion Corrosion Topics NAVSEA Basic Paint Inspector Training! 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 l Definition: What Is Corrosion? 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 2 1

7 NAVSEA Basic Paint Inspector Training: Corrosion Environment Meanings Corrosion Cycle 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 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 External Circuit Electron Flow! Steel:Anode! Fe++! Bronze:Cathode! Seawater Electrolyte Ionic Dissolution 2 2

8 NAVSEA Basic Paint Inspector Training: Corrosion Electrolytic Cell Where s the bronze? External Circuit Electron Flow Steel:Cathode Zn++ Zinc:Anode Zn++ Bronze:Cathode Seawater Electrolyte Ionic Dissolution Unpainted bronze ship propellers provide a large area for galvanic coupling. General Corrosion Corrosion Cell A Picture is Worth a Thousand Words Minute differences between individual grains leads to anode/cathode pairs and general corrosion. Typical grain structure of metal Anode Cathode pairs in steel continue to be active over time See how steel will waste away 2 3

9 NAVSEA Basic Paint Inspector Training: Corrosion Corrosion cells can continue right through to the other side There s usually more corrosion than 1 st meets the eye Corrosion Cells work inside the steel and under the preservation Galvanic Series in Seawater Sometimes it s discovered too late. More likely to corrode (Anodic) Less likely to corrode (Cathodic) 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 Types of Corrosion No 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. 2 4

10 NAVSEA Basic Paint Inspector Training: Corrosion Uniform Corrosion Uniform Corrosion USS ANONYMOUS Fan Room! Dissimilar Metal Dissimilar Metal Dissimilar Metal Embedded in Aluminum Creates Corrosion Cell Brass shock mounts for light on aluminum mount. Pitting Pitting Severe pitting of 410 stainless steel. 2 5

11 NAVSEA Basic Paint Inspector Training: Corrosion 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 2 6

12 NAVSEA Basic Paint Inspector Training: Corrosion Intergranular Exfoliation Intergranular corrosion of sensitized stainless steel Exfoliation Exfoliation Aluminum Grain Structure Grains are flattened and elongated during rolling of aluminum plate Aluminum alloy plate! l Humidity/Oxygen Environmental Effects l Humidity/Oxygen l Salt Water Environmental Effects Corrosion of Underwater Hull! General Corrosion 2 7

13 NAVSEA Basic Paint Inspector Training: Corrosion Environmental Effects Environmental Effects l Humidity/Oxygen l Salt Water l Chemicals l Humidity/Oxygen l Salt Water l Chemicals l Heat/Temperature Corrosion of Battery Box Caused by Battery Acid Corrosion of Steam Piping Environmental Effects Environmental Effects l Humidity/Oxygen l Salt Water l Chemicals l Heat/Temperature l Stack Gases 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! l UV Radiation Chalking of an epoxy topcoat eventually coating will fail allowing corrosion of substrate! Open Forum Summary 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 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 2 8

14 NAVSEA Basic Paint Inspector Training: Corrosion Control Corrosion Control Topics l Three mechanisms of corrosion control by coatings (barrier, sacrificial, inhibitive) NAVSEA Basic Paint Inspector Training! l Sacrificial and impressed current cathodic protection systems Scope Learning Outcome l Acquaints students with the basic mechanisms for controlling corrosion on Navy ships (coating and cathodic protection) and how they work well together 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 Coatings to Prevent Corrosion l Materials Selection l Control Environment l Design Details 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 3 1!

15 NAVSEA Basic Paint Inspector Training: Corrosion Control 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 Sacrificial Primers 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) Topcoat! Zinc Rich! Coating! Anode! Steel Substrate: Cathode! In sacrificial primers, pigments provide active electrochemical protection by reacting with the environment.! Water! Electrolyte! Sacrificial Primers Class Input 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. l Name some other types of sacrificial coatings processes Galvanizing (zinc) Electroplating (zinc, cadmium) Metal Spray Coatings (zinc, aluminum) 3 2!

16 NAVSEA Basic Paint Inspector Training: Corrosion Control Inhibitive Primers Inhibitive Primers Inhibitive Primer! Moisture Penetration! Substrate! Inhibitive coatings react with moisture absorbed by the topcoat to form products which inhibit the corrosion process.! 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 Sacrificial Anodes 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 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 Sacrificial Anodes The deterioration of the anode is indicative of a properly working anode.! 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?! 3 3!

17 NAVSEA Basic Paint Inspector Training: Corrosion Control Sacrificial Anodes Sacrificial Anodes l Zinc and Aluminum anodes self-regulating l Magnesium anodes and impressed current systems not self-regulating This poor guy really thinks he has a relic from the American Revolution! Cathodic Protection Failed Dielectric Shield (called Capastic Shield in ) Basic Impressed Current Cathodic Protection (ICCP) System! Rust bleed through a dielectric shield indicates cracks which penetrate to the hull Failed Dielectric Shield ICCP Components Note calcareous deposits at failure sites in dielectric shield! Properly Operating ICCP Anode With Dielectric Shield Bleaching (often called a Flame pattern) 3 4!

18 NAVSEA Basic Paint Inspector Training: Corrosion Control Cathodic Protection Cathodic Protection for Your Car 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 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 3 5!