SSPC Protective Coatings Inspector Training
and Certification (PCI)
Table of Contents
Module One: Protecting Steel from Corrosion: The Role of Protective
Coatings………2 Module Two: The Roles of Quality Assurance (QA) and Quality Control (QC) Inspection Personnel on a Coating Project………...7 Module Three: Surface Preparation Methods, Industry Standards, and
Inspection……….……….15 Module Four: Practical Arithmetic for the Coatings Inspector……….31 Module Five: Coating Mixing, Thinning, and Application: Equipment Overview and Inspection Techniques………...43 Module Six: Industrial and Marine Protective Coatings and Coating
Systems………..62 Module Seven: Specialty Inspection Projects………...69 Module Eight: Coating Failures: Investigation Procedures and Case
Studies………74 Module Nine: Inspector Safety………..77 Module Ten: Navigating Coatings Specification……….. 82 Module Eleven: Specification Review and Pre-Construction Conference; Inspection Plan Development for the Inspection of Fuel Tank Lining Installation………..84 Module Twelve: Project Inspection Workshop………...85 Appendix A
Quiz Answer Keys………....A-1 Appendix B
Glossary………B-1 Appendix C
Module One: Protecting Steel from Corrosion: The Role of Protective Coatings Module one explains how coatings protect metals from corroding. Corrosion is a process where made metals give up energy and return to their natural state. Some man-made metals have a stronger propensity to corrode than others, but all man-man-made metals corrode eventually. Only four elements need to be present for corrosion to occur: an anode, a cathode, a metallic pathway, and an electrolyte. While the corrosion of man-made metals cannot be completely halted, it can be controlled. The most widely used method to prevent/slow corrosion today, particularly on carbon steel, is the application of high performance coatings. Module One explains how today’s high performance
coatings use barrier protection, sacrificial or cathodic protection, and inhibitive protection to protect modern day steel structures from the inevitable process of deterioration and decay.
Learning Outcomes
At the completion of this module you should be able to: - Identify the elements of a corrosion cell
- Describe the corrosion of man-made metals - Explain how industrial coatings control corrosion
- Describe alternative methods used to protect carbon steel from corrosion Identify the Elements of a Corrosion Cell
Corrosion will occur when four required elements are present. If any one of the elements is missing, the corrosion process will not proceed. The required elements, which
compose a “corrosion cell” are: 1. Anode
2. Cathode
3. Metallic Pathway (connecting the anode and cathode) 4. Electrolyte
Corrosion of Man-made Metals
A metal in its pure form will begin to corrode and revert to its natural state when all of the elements of a corrosion cell are present. Exposure to air and water are usually enough to get the process started and the metal surface begins to corrode and oxidize (oxidation is another term that is sometimes used along with corrosion and simply refers to reaction with oxygen.)
Explain How Industrial Coatings Control Corrosion
Corrosion of metals really cannot be completely stopped. Slowing down the process as much as possible is the only option to preserve the metal and this is where protective coatings play a crucial role. Coatings are considered to function as a protective layer in three different ways: by providing barrier, sacrificial or inhibitive protection.
Describe Alternative Methods Used to Protect Carbon Steel from Corrosion Cathodic protection can be provided by passive or active means. Passive cathodic protection can be accomplished by attaching a dissimilar metal directly to a metal substrate to act as a sacrificial anode to corrode preferentially.
Active cathodic protection can be provided by applying or “impressing” an electrical current to the structure.
Module One: Protecting Steel from Corrosion: The Role of Protective Coatings Quiz 1
1. Corrosion is defined as the ________________ of _________________________. 2. Carbon steel _____________________ energy during the corrosion process. 3. The use of ________________ __________________ is the most widely used
method of corrosion control.
4. List four elements of a corrosion cell: _____________________________ _____________________________ _____________________________ _____________________________
5. Which of the four elements in question 4 does a protective coating prevent from contacting the steel? __________________________________________________ 6. When corrosion occurs, the _____________________ depletes or decays.
7. If a copper pipe is combined to an aluminum pipe without an insulator, which metal represents the anode?
_____________________________________________________
8. List two dissimilar metals that are intentionally coupled in the protective coatings industry as a method of corrosion prevention?
________________________ and ____________________________ 9. What type of chemical will deteriorate uncoated weathering steel? _________________________
10. ___________________ pigments form plate-like layers and provide barrier protection to steel surfaces.
11. What two elements are prevented from contacting steel when a barrier-type coating is employed? _____________________ and ___________________________ 12. Zinc-rich primers protect the steel by _______________ and ________________
protection.
13. Thermal spray metallizing and galvanizing protect the steel by _______________ and ________________ protection.
14. Borates, chromates, phosphates and other pigments protect the steel by _________________.
15. Cathodic protection can be in the form of ______________________ _______________ or __________________ current.
16. ___________________ is considered passive cathodic protection. 17. ___________________ is considered active cathodic protection.
18. Cathodic protection is used in conjunction with ___________________ _________________.
19. _________________ and __________________ are metals that form a protective oxidation layer.
Module One: Protecting Steel from Corrosion: The Role of Protective Coatings Supplemental Reading
- Corrosion and Coatings: An Introduction to Corrosion for Coatings Personnel (SSPC Item #98-08)
- Corrosion Prevention by Protective Coatings (SSPC Item #00-16) - Value of Coatings (SSPC Item VT-VOC)
Module Two: The Roles of Quality Assurance (QA) and Quality Control (QC) Inspection Personnel on a Coating Project
Module Two compares the roles of QA and QC inspectors on coatings projects. All too often, the lines between the QC and the QA on a coatings project get blurred. When that happens, the scope of work and responsibility for that work can get blurred in the
process. This module is designed to clarify the common roles and responsibilities of both the contractor’s QC inspector and the Owner’s QA inspector. This is a textbook: the way it would work in a perfect world, but it is helpful to know how things “could/should” work before getting caught up in the day to day rush of a real world coatings project. Module Two compares and contrasts the role of the QA and QC inspector on a typical coatings project. The commonalities will be explored, including understanding the specification, reviewing the product data sheets (the PDS) and the material safety data sheet (the MSDS), comprehending the industry standard relevant to the specific project, documenting hold or checkpoints, understanding paper trails, and taking responsibility for ethics on the job. Module Two also explores the critical differences in the two roles, including issues of authority, reporting, testing, and documentation (which again, depends on the scope of work and the specification). Another issue explored by this module is the management of nonconformities.
Learning Outcomes
At the completion of this module you should be able to:
- Describe the differences between quality assurance and quality control
- Describe the common duties of quality assurance and quality control personnel - Describe the purpose and content of a pre-job conference
- Explain the purpose of an inspection procedure/plan - Explain the importance of ethics of inspection personnel Describe the Differences Between Quality Assurance and Control
Quality control (QC) is performing necessary observations, testing and documentation that verifies the work performed meets or exceeds some minimum standard as required by the project specification. Quality control is the contractor’s responsibility. Quality control involves the routine and systematic inspection and tests that are conducted to verify that each phase of the work (hold point) is in compliance with the specification. Quality Assurance (QA) is defined as the process to verify that the quality of work
performed is actually what was reported by quality control. Quality assurance is typically performed by the owner (e.g. facility project engineer) or a third party on behalf of the Owner.
Describe the Common Duties of Quality Assurance and Control Personnel Hold point inspections are typically done at:
1. Pre-cleaning
2. Surface Preparation 3. Primer Application
5. Top Coat Application 6. Cure
QC inspection should occur first and any non-conforming items identified by QC should be corrected, re-inspected and accepted by the QC. The QA observations should only occur after the work (hold point) has been accepted by the QC. The QA should then verify that the work that the QC accepted meets the requirements of the specification. Describe the Purpose and Content of a Pre-job Conference
The pre-job conference should provide a review for all parties on the organizational structure and representatives of each stakeholder. This should include the title and responsibilities of each person as well as their reporting relationship within the company or organization.
The pre-job conference should summarize the contractor’s approach to the project including: schedule, location(s) of equipment, and manpower estimates.
The pre-job conference should review the specification and sequence of work, address specification discrepancies, and discuss how QC and QA inspections will be coordinated and implemented. It should include discussion of preparation of test sections, if required; adequate lighting; inspector safe access; inaccessible areas; and other project-specific considerations.
The final phase of the pre-job conference should include a discussion of all required QC and QA documentation and submission schedules. The Owner should also address the procedure that should be followed if there are discrepancies in the QC and QA
documentation.
Explain the Purpose of an Inspection Procedure/Plan
Project specifications can often be complex and contain many details unrelated to surface preparation and painting. As a result, locating the inspection check points can be
cumbersome and time consuming. More consequential, key inspection checkpoints may be overlooked. The development of an inspection procedure before the project begins can aid the inspector in identifying the inspection checkpoints and the associated acceptance criteria.
Explain the Importance of Ethics of Inspection Personnel
Ethics is defined as “motivation defined by the ideas of right and wrong.” The legal definition of ethics is “of or relating to moral action and conduct; professionally right; conforming to professional standards.”
Regardless of whether the coating inspector is functioning as QC or QA, the inspector must have a high level of personal integrity and a strong work ethic to provide quality monitoring of the project and a fair accounting to all involved parties. The inspector should not impose personal standards of quality or work, and must remain constantly aware that the criteria for work acceptance are the specification requirements.
Module Two: The Role of Quality Assurance (QA) and Quality Control (QC) Inspection Personnel on a Coating Project
Workshop: Ethics
As a group, review each of the scenarios below and discuss and answer the questions. Have a group spokesperson prepared to discuss your group’s answers at the end of the session.
SCENARIO 1:
You are performing part-time third party Quality Assurance services for the Owner. The contractor blast cleaned and painted while you were not on-site. When you arrive on-site, the Owner hands you a piece of paper that says “Tuesday, surface preparation OK. Ambient OK 100 gallons primer applied, OK.” He asks you to record this information on a dated inspection report and to sign it.
Question 1: Do you record the information?
_________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ Question 2: If yes, how do record it “ethically?”
_________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ Question 3: If no, what action(s) should you take?
_________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ SCENARIO 2:
You are hired by a Facility Owner to provide third party QA. You’ve been assigned to go out-of-town and are living in the same hotel as the contractor’s workers. You often see them in the hotel bar. Every time you are at the bar, the contractor pays for your drinks. Question 1: Is it okay to accept the “free” drinks?
_________________________________________________________________________________ _________________________________________________________________________________
_________________________________________________________________________________ Question 2: If no, how might you prevent this from occurring or handle it ethically?
_________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ SCENARIO 3:
The coating manufacturer is on-site passing out free hats. Question 1: Is it okay to accept the “free” hat?
_________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ SCENARIO 4:
You’ve been working as the Facility Owner’s QA on the same out-of-town project with the same contractor for over a year. You have a good working relationship. Your vehicle breaks down and you cannot replace it. The contractor allows you to use the company pick-up truck. He also gives you his credit card to use for gas.
Question 1: What are the potential risks to this arrangement?
_________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________
Question 2: List 3 potential ethical breaches related to this scenario:
_________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ SCENARIO 5:
You are the contractor’s QC. You measure the ambient conditions prior to the start of painting with an epoxy primer and they comply with the specification. However, during painting you notice that the weather is changing and obtain additional ambient
temperature. You advise the foreman, who tells you that his application is underway and that he’s going to finish painting, regardless of the conditions. He tells you to ignore it, to not record the additional measurements, and just let him finish the job.
Question 1: Should you record the conditions?
_________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ Question 2: If yes, what then?
_________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ Question 3: If no, why?
_________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ Question 4: What other actions should be taken by the QC?
_________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________
Module Two: The Role of Quality Assurance (QA) and Quality Control (QC) Inspection Personnel on a Coating Project
Quiz 2
1. _________________ ___________________ is performing observations and tests, and documenting that the work meets/exceeds the specification requirements.
2. ________________ ____________________ is the contractor’s responsibility. 3. ________________ ____________________ is the process to verify the quality of work performed as reported by quality control personnel.
4. ________________ ____________________ is performed by the ______________ or a ________________ _____________________ on behalf of the __________________. 5. When an _______________ performs QA with his direct staff, he has a
______________________ _________________________ with the contractor and can exert control.
6. When an _____________ __________ performs QA for the owner, he does not have ______________________ _________________________ with the contractor and can only _________________ and document, and advise the __________________ QC. 7. Independent of whether _________________ ______________ personnel are on-site, the contractor remains responsible for __________________ _____________________. 8. When work is halted for an inspection, it is known as a __________ _____________ inspection.
9. List six common hold point inspections:
_________________________________ _________________________________ _________________________________ _________________________________ _________________________________ _________________________________ 10. Which party should inspect the completed work first, QA or QC? ______________ 11. If the inspected area is deficient, which party should inspect the surface first after the rework is completed, QA or QC? _____________________
12. ________ observations and test results typically supersede those of __________. 13. Prior to a pre-construction conference an inspector should ______________ the ______________________________.
14. List seven topics that should be discussed at a pre-construction conference:
_________________________________ _________________________________ _________________________________ _________________________________ _________________________________ _________________________________ _________________________________
15. An inspection plan can contain three columns, titled as: _________________________________
_________________________________ _________________________________
16. The content of the “acceptance criteria” section for an inspection plan comes from the _________________________________
17. A Work Plan should cover the individual _________________ of a project, including both _________________________ and ___________________________.
18. A Work Plan is also known as a ____________________ ____________________ _____________________________.
19. One of the most important responsibilities of a coatings inspector is to ______________ the results of _______________________.
20. Fraudulent documentation, falsification of time/expense reports and acceptance of gifts in exchange for lenient inspection are ________________ ________________.
Module Two: The Role of Quality Assurance (QA) and Quality Control (QC) Inspection Personnel on a Coating Project
Supplemental Reading
- Planning and Specifying Industrial Protective Coating Projects (SSPC Item #04-10) - The Inspection of Coatings and Linings: A Handbook of Basic Practice for Inspectors, Owners, and Specifiers, 2nd Edition (SSPC Item #03-14)
Module Three: Surface Preparation- Methods, Industry Standards and Inspection Module three explains the inspection of surface preparation. Inadequate surface
preparation may be the most costly phase of a coating operation, and it is always critical to the project’s success. Surface preparation has a major focus in this training program, which covers in detail common standards used throughout the industry. The initial phase of pre-surface preparation and the inspection hold points are covered first, detailing the problems of weld spatter, edges, and repair areas. SSPC: The Society for Protective Coatings has developed a series of consensus standards to govern the surface cleanliness requirements. Currently, there are thirteen consensus standards for surface preparation. Each of these standards will be explored, including descriptions of what must be removed from the surface and what may remain on the surface for each standard. In addition to the surface preparation standards, the training will also focus on means and methods, including: blast cleaning equipment, a variety of abrasives, wet and dry abrasive blast cleaning, centrifugal blast cleaning, vacuum blast cleaning, hand and power tools, and waterjetting. The final focal points for Module Three are the common inspection checkpoints for surface preparation and the methods used to verify adherence to the specification.
Learning Outcomes
At the completion of this module you should be able to:
- Describe the importance and dual objective of proper surface preparation - Define the SSPC, NACE, and ISO standards for surface preparation - Describe common methods used to prepare surfaces for coating
- Describe methods used to control an environment during surface preparation activities
- Measure and record surface profile - Evaluate surface cleanliness
Describe the Importance and Dual Objective of Proper Surface Preparation The purpose of surface preparation is two-fold: to clean and to roughen the substrate according to the requirements of the specification. Sometimes the methods used to prepare surfaces for coating application achieve these criteria simultaneously (as with abrasive blast cleaning), while other times these steps must be performed separately (as with chemical stripping). In either case, the inspector must treat these as two distinct “acceptance criteria,” as the level of cleaning may be adequate, but the roughness may be insufficient or excessive. Alternatively, the surface roughness may be on target, but the level of cleaning may be inadequate.
Define the SSPC, NACE, and ISO Standards for Surface Preparation
The SSPC, NACE and ISO surface cleanliness standards prescribe a minimum acceptable level of cleaning, depending upon the specified degree of cleanliness required. The standards are known as “consensus documents” that are created by industry experts for inclusion in coatings specifications. They are not laws or regulations, but they become “contract law” once they are invoked in a specification for a coatings project. There are currently thirteen SSPC surface cleanliness standards. SSPC and NACE have jointly
published seven of them; SSPC is the sole publisher of the remaining six. The written standards for surface cleanliness are contained in Volume 2 of the SSPC Painting Manual, “Systems and Specifications” and are available for individual download from www.sspc.org. ISO currently has seven surface cleanliness standards. These standards define the level of cleaning required, and many of them are accompanied by visual guides that an inspector can use to verify that the minimum level of cleaning has been achieved. Describe Common Methods used to Prepare Surfaces for Coating
Surface preparation methods employed by a painting contractor or facility owner can range from simple solvent cleaning to hand and power tool cleaning, dry and wet abrasive blast cleaning, chemical stripping, waterjetting and other more non-traditional methods such as sponge jetting and cryogenic blast cleaning using dry ice pellets. The degree of cleaning required by a given project specification is dependent on the service environment (the environment the coating must perform in), the coating system and the intended service life of the coating once installed.
Describe Methods used to Control an Environment During Surface Preparation Activities
The measurement of air temperature, relative humidity, dew point temperature, and surface temperature is usually associated with coating application. However, if the air temperature and relative humidity are such that moisture from the air condenses on the surface during final surface preparation, the surface may flash rust. Therefore, it is important to verify that the temperature of the surface is at least 3°C (5°F) higher than the temperature of the dew point, to preclude airborne moisture from condensing on the surfaces.
These values (surface temperature and dew-point temperature) can be obtained using sling or battery-powered psychrometers in conjunction with US Weather Bureau Psychrometric Tables and surface temperature thermometers, or can be obtained using direct read-out electronic psychrometers equipped with surface temperature probes. The step-by-step use of this instrumentation is described below. It is important that the inspector not rely on prevailing weather conditions from a local service (e.g., airport weather station) as conditions at the project site and the specific work area can vary considerably. Ambient conditions should be measured and recorded prior to initiating final surface preparation and at 4-hour intervals thereafter, unless conditions appear to be declining. In this case, more frequent checks may be required. If surface preparation work will be done inside a facility, tank or inside of a containment, then the prevailing ambient conditions inside of the areas (at the actual location of the work) should be assessed. The location, date, time of day and the condition of air temperature, relative humidity, dew-point temperature and surface temperature should be recorded. However, since the only operation being monitored is surface preparation, the dew point/surface temperature relationship is most critical. Typically, there is no specified range for air temperature and relative humidity during surface preparation operations.
Measure and Record Surface Profile
Surface profile is defined as the average peak-to-valley depth that is generated by abrasive impacting the surface at high speed and by the impact created using certain power tools. By imparting a profile, the surface area is increased, enhancing the adhesion of the coating system to the surface. While an insufficient surface profile depth may result in poor coating system adhesion, excessive surface profile may cause pinpoint rusting and will require significantly more coating to fill all of the “valleys” of the surface profile and provide the specified thickness of coating above the “peaks” of the surface profile. Therefore, compliance with the minimum and maximum specified surface profile depth is critical to the success of a coating system.
Factors affecting the depth of the surface profile include (for abrasive blasting) the type, hardness and size of the abrasive media employed, as well as the hardness of the surface being prepared. Lesser factors include the distance from the blast nozzle to the surface. For power tool cleaning, the type of tool and the configuration of the “impactors” will oftentimes dictate the depth of the surface profile. Adjusting to changes in profile depth requirements in specifications is best achieved by selecting a different sized abrasive. For projects requiring a relatively shallow surface profile depth, a smaller abrasive should be selected. For projects requiring a relatively deep surface profile, a larger abrasive should be selected, but may be blended with a smaller abrasive to increase productivity. Because of the industry’s recognition of the importance of surface roughness
characteristics (beyond average surface profile depth), ASTM D7127, “Standard Test Method for Measurement of Surface Roughness of Abrasive Blast Cleaned Metal Surfaces Using a Portable Stylus Instrument” was published in 2005. The standard describes the procedures for verifying accuracy and using portable stylus-type instruments to obtain surface characterization data. An inspector may be required to perform peak count measurements in addition to peak-to-valley depth measurements (if required by the project specification).
There are four industry-recognized standards for measuring surface profile, including ASTM D4417, “Test Methods for Field Measurement of Surface Profile of Blast Cleaned Steel;” NACE RP0287, “Field Measurement of Surface Profile of Abrasive Blast Cleaned Steel Surfaces Using a Replica Tape;” ASTM D7127 “Standard Test Method for
Measurement of Surface Roughness of Abrasive Blast Cleaned Metal Surface Using a Replica Tape;” ASTM D7127 “Standard Test Method for Measurement of Surface Roughness of Abrasive Blast Cleaned Metal Surfaces Using a Portable Stylus
Instrument.” These methods prescribe how to obtain measurements of surface profile depth and peak count, but do not provide an acceptance criterion (e.g., “the surface profile shall be 50-88 µm [2-3.5 mils…”]. Therefore, the project specification must indicate the desired surface profile depth and the minimum peak count (as required).
Evaluate Surface Cleanliness
There are four visual standards that have been developed for industry use by SSPC. To select the correct visual standard, simply ask yourself, “What does the project
specification require regarding the method of surface preparation?” Then select from one of the four visual standards currently available:
- SSPC-VIS 1, “Guide and Reference Photographs for Steel Surfaces Prepared by Dry Abrasive Blast Cleaning,”
- SSPC-VIS 3, “Guide and Reference Photographs for Steel Surfaces Prepared by Power and Hand Tool Cleaning,”
- SSPC-VIS 4/NACE VIS 7, “Guide and Reference Photographs for Steel Surfaces Prepared by Waterjetting,” or
- SSPC-VIS 5/NACE VIS 9, “Guide and Reference Photographs for Steel Surfaces Prepared by Wet Abrasive Blast Cleaning.”
These visual standards are designed for use as guides. In the event of a dispute, it is the written surface cleanliness definitions that prevail. Also, the photographs in the standard will likely not provide an exact match to the surfaces prepared on your project, because the initial condition of the surface, the abrasive or tool employed, the surface profile, lighting and other factors can affect the appearance of the surface. Therefore the visual standards are truly designed as guides. In fact, many specifications now require the contractor to prepare a project specific cleanliness standard on the actual structure to be cleaned and coated. The project-specific standard represents the actual initial condition, the actual abrasive or tool employed, the surface profile depth and other jobsite
conditions. The SSPC visual standards can be used during this process to establish the minimum acceptable cleanliness level for the specific project. Once established, this area can be preserved until the surface preparation portion of the project is completed.
Module Three: Surface Preparation- Methods, Industry Standards and Inspection Workshop: Case Study
Surface Preparation of the Interior and Exterior of the Sun
Spree Township Elevated Potable Water Storage Tank
Project DescriptionThe Sun Spree Township Municipal Authority (a suburb of Ft. Lauderdale, FL) commissioned a coating condition survey of their 50 year old elevated potable water storage tank. The engineering firm’s report recommended total removal and replacement of the lining on the interior of the tank, as well as removal of the coating on the exterior of the tank, which contains both lead and chromium pigmentation in the existing coating. The exterior surfaces (underside of the bowl) also contain high levels of chloride (range of 50 to 100 µg/cm2), which is likely due to the proximity of the tank to the beach front. Sun Spree Township awarded the surface preparation and coating application work to Smith Bros. Contracting, a local QP1 certified firm that specializes in industrial surface preparation and painting. Smith Bros. is responsible for providing a trained specialist to perform quality control throughout the project. You are employed by Sun Spree
Township as the resident corrosion specialist, and will be performing quality assurance oversight on the project.
The information provided below was excerpted from the project specification and only pertains to surface preparation activities:
Abrasive Recyclable steel grit (conforming to
SSPC-AB 2 and SSPC-AB 3)
Surface Cleanliness of Interior Surfaces SSPC-SP 10/NACE No. 2 Surface Cleanliness of Exterior Surfaces SSPC-SP 6/NACE No. 3 Cleanliness of Compressed Air Per ASTM D 4285 (once/shift)
Minimum Blast Nozzle Pressure 758 KPa (110 psi)
Surface Profile of Interior and Exterior Surfaces Angular; 50-87.5 microns (2-3.5 mils); Minimum peak count: 34/cm
Minimum Lighting for Surface Preparation 500 Lux (47 foot-candles) Minimum Lighting for Inspection 2000 Lux (186 foot-candles)
Environmental Conditions Surface temperature a minimum of 3°C (5°F) above dew point
Maximum Surface Contamination Levels-Interior Per SSPC-SP12; Level NV-1 Maximum Surface Contamination Levels-Exterior Per SSPC-SP12; Level NV-2
Surface Dust Quantity Rating 1
Surface Dust Size Rating 2
Maximum Time Between Surface Preparation and Primer Application
8 hours
Work together in your teams to address each of the quality-related issues described below. Elect a team spokesperson to present your answers to the class and be prepared to defend them if questioned.
1. As the quality assurance inspector, how would you determine whether the abrasive the contractor has mobilized on the project site conforms to SSPC-AB3?
2. The contractor spent extra time preparing the exterior surfaces, and even exceeded the specified level of cleanliness (approached level SSPC-SP 10). However, the surface began to rust bloom before the primer could be applied. By coincidence, the amount of rust bloom did not exceed 33% of the surface. The contractor is claiming that the surface meets the minimum level of cleanliness required by the specification and wants to proceed with primer application. The surface preparation-to-primer application time is within the 8-hour window. Explain how you would respond.
3. The cleanliness of the compressed air was assessed by the quality control specialist upstream of the moisture and oil extractor. Comment as to whether this test was performed properly.
4. The blast nozzle pressure was reportedly measured by the quality control specialist before production blast cleaning was initiated and was recorded as 862 KPa (125 psi). During production abrasive blast cleaning, you ask the quality control specialist to re-measure the blast nozzle pressure, and the gage read 620 KPa (90 psi). Based on this information, answer the following:
Does the “during production” pressure reading conform to the specification?
What may be causing the difference in the two pressures?
5. The interior steel surfaces of the tank contain pitting of the steel. Inspection of the surfaces after abrasive blast cleaning revealed trace amounts of paint residue in the bottom of the pits. However, the residue is only visible using a 10X illuminated magnifier. Is the presence of this residue cause for re-blasting of the surfaces?
6. The quality control specialist tested the condition of the recycled abrasive and recorded that the abrasive samples collected contained 2% of non-abrasive residue. Does the abrasive meet the requirement for non-abrasive residue under SSPC-AB2?
7. After 5 hours of production blast cleaning on the interior of the tank, the surface profile depth was measured by the quality control specialist and recorded as 107 µm (4.2 mils), with a peak count of 40/cm.
Does the surface roughness meet the requirements of the project specification?
If no, describe what steps the contractor may take to correct the non-conformity.
If no, describe what the contractor could have done to avoid the non-conformity.
8. The quality control specialist assessed the amount of light inside the tank prior to surface preparation operations. The amount of light was measured and recorded as 600 Lux (56 foot-candles).
Does this conform to the project specification?
The same amount of light was available when he assessed the surface cleanliness. Is this acceptable? Explain.
9. The quality control specialist measured the ambient conditions and surface
temperature prior to abrasive blast cleaning. The surface temperature was 2°C (3ºF) above the dew point, but the conditions appeared to be improving, so the quality control specialist allowed the contractor to proceed. Was this acceptable? Explain.
10. The quality control specialist reported the following levels after assessing the cleanliness of the exterior surfaces. Do the surfaces meet the requirements of the project specification? Meets Specification CHEMICALChemi cal LLEVEL Yes No Chloride 12 µg/cm2 Ferrous Ion 3 µg/cm2
Module Three: Surface Preparation- Methods, Industry Standards and Inspection Quiz 3
1. Preparing a surface for coating application is the most _________ and typically the most ____________________ step.
2. List five common responsibilities of a coatings inspector relating to surface preparation:
______________________________ ___________________________ ______________________________ ___________________________ ______________________________
3. The two-fold purpose of surface preparation is to _________________ and ____________________the substrate.
4. ____________________and ____________________have prepared a standard and a recommended practice for measurement of ____________________.
5. ____________________dictates the required surface profile depth.
6. The surface profile or anchor pattern must be ____________________ with the entire ____________________.
7. List two “fabrication defects” that may be addressed in a coating specification. ____________________ ____________________
8. List three methods that can be used to inspect surfaces for the presence of grease/oil:
____________________ ________________ ____________________ 9. ____________________occurs between mating surfaces, while
____________________forms on the surface of the steel.
10. Chemical contaminants like chloride trapped beneath a coating film can cause ____________________blistering, ____________________and
____________________failure.
11. Testing for chemical contamination involves two steps: ____________________ and ____________________.
12. ____________________environments are more conducive to coating
deterioration caused by chemical contamination beneath the coating film than ____________________ environments.
13. Suggested thresholds for soluble salt concentrations are found in the appendix to _____________________________________________.
14. The depth and shape of the surface profile generated by abrasive blast cleaning is determined by the ____________________and the ____________________ of the surface.
15. Abrasives fall into two general categories, ____________________ and ____________________.
16. SSPC AB 1 categorizes abrasives according to ____________________, ____________________and ____________________.
17. The abrasive cleanliness requirements in SSPC abrasive specifications AB1, AB2 and AB3 are ____________________requirements of the SSPC abrasive blast cleaning surface cleanliness standards.
18. List four tests that an inspector can perform in the field to verify conformance to SSPC AB1:
______________________________ ___________________________ ______________________________ ___________________________ 19. SSPC AB2 governs the quality of ____________________.
20. Steel grit produces an ____________________-shaped surface profile. 21. Steel shot produces a ____________________-shaped surface profile.
22. List three tests that an inspector can perform in the field to verify conformance to SSPC AB3:
______________________________ ___________________________ ______________________________
23. List one test that an inspector cannot perform in the field to verify conformance to SSPC AB2: ____________________.
24. The diameter of an S330 steel shot abrasive is ____________________. 25. Which abrasive is larger, G25 or G50? ____________________.
26. Centrifugal blast machines often incorporate a blend of
____________________and ____________________abrasives.
27. Wet abrasive blast cleaning is used when ____________________must be controlled.
28. High pressure water jetting incorporates pressures from _______ to _____ MPa. 29. Chemical strippers do not remove ____________________or
____________________and will not generate a ____________________. 30. Three methods used to prepare concrete for coating include:
______________________________ ___________________________ ______________________________
31. SSPC surface cleanliness standards become contract law once they are invoked by the ___________________.
32. SSPC-SP1, “___________________” is an ___________________requirement of the SSPC surface cleanliness standards.
33. SSPC-SP2 “___________________” requires the removal of all ___________________& ___________________.
34. SSPC-SP2 requires the use of a ___________________as the inspection tool. 35. SSPC-SP3 “___________________” requires the removal of all
___________________mill scale, rust & ___________________.
36. What is the primary difference between SSPC-SP15, “___________________” and SSPC-SP11, “___________________?”
_____________________________________________________.
37. In addition to solvent cleaning ___________________is an indirect requirement of SSPC-SP3, SP15 and SP11.
38. Which two SSPC surface cleanliness standards invoke a minimum surface profile requirement? ___________________and ___________________
What is the minimum requirement? ___________________
39. List three possible “indirect requirements” of the SSPC abrasive blast cleaning standards:
______________________________ ___________________________ ______________________________
40. The amount of staining allowed by the SSPC abrasive blast cleaning standards is based on what area? __________________
41. SSPC-SP___/NACE No. 4, “__________________” requires the removal of all __________________rust, paint & mill scale.
42. SSPC-SP14/NACE No. ___, “___________________Cleaning” allows up to ___% ___________________ rust, paint or mill scale to remain. The amount of staining is ___________________.
43. The only difference between SSPC-SP ___/NACE No. 3, “___________________” and SSPC-SP10/NACE No. ___, “___________________” is ____________________________.
44. SSPC-SP___/NACE No. 3 allows up to ___% staining to remain on each ___ square inch area.
45. SSPC-SP10/NACE No. ___ allows up to ___% staining to remain on each ___square inch area.
46. SSPC-SP___/NACE No. ___allows no paint, rust, mill scale or straining to remain.
47. SSPC-SP___/NACE No. ___, level WJ-2 allows up to ___% of the surface to contain straining or tightly adhering matter.
48. The “L” in “SSPC SP12-WJ-3-L” indicates ______is permitted by the specification.
49. ISO St2, “___________________” requires removal of all ___________________materials.
50. ISO ___, “___________________” allows only stains to remain on the surface. 51. The SSPC/NACE and ISO cleanliness standards prohibit the use of
___________________ when inspecting surface cleanliness.
52. Prior to final surface preparation, it is recommended that the inspector verify that the ___________________ temperature is at least ___oF (___oC) higher than the ___________________ temperature.
53. Dehumidification equipment ___________________ moisture from the air. 54. List three methods of dehumidification: ___________________,
55. Cooling air below the dew point for dehumidification of the air is the ___________________ method.
56. Products that absorb moisture from the air as a means of dehumidification use the ___________________ method.
57. Indicate the procedure for conducting a compressed air cleanliness test, below: Conduct the test ___________________ stream of ___________________ and oil separation. Position the air outlet ___” from the collector
Exhaust the compressed air onto the collector for approximately ______. 58. To conduct a “vial test,” fill a clear container with ___abrasive and an equal
amount of ___________________. Allow the shaken blend to settle for ___________________.
59. The maximum abrasive conductivity according to the SSPC abrasive specifications is ___µS.
60. The minimum level of lighting for inspection is ___ Lux.
61. The recommended level of lighting for inspection is ___ ft/candles. 62. The visual standard reference “G2 SP14” in SSPC VIS 1 indicates:
___________________________________________________. 63. The visual standard reference “F SP3 PWB” in SSPC VIS 3 indicates:
______________________________________________________
64. The visual standard reference “D WJ3 M” in SSPC VIS 4/NACE VIS 7 indicates: __________________________________________________________
65. The visual standard reference “C WAB 6 H” in SSPC VIS 5/NACE VIS 9 indicates: _______________________________________________ 66. The visual standard reference “A Sa3” in ISO 8501-1:1988 indicates:
__________________________________________________
67. Surface profile is defined as the maximum ___________________depth. 68. Profile generation ___________________ the surface area of the steel. 69. An increase in peak count reportedly enhances ___________________and a
greater resistance to ___________________.
70. The ___comparator disc is selected for inspection of surface profile when garnet abrasive is used to perform abrasive blast cleaning.
71. “3.0SH76” on a comparator disc segment indicates: ___________________. 72. Verify “zero-set” on a surface profile depth micrometer using a
___________________.
73. The measuring range of X-Coarse replica tape is ___mils. 74. The thickness of the Mylar film on replica tape is ___ mils.
75. Each grade of replica tape is most accurate in the ___ of the range. 76. Complete the following chart:
Parts Per Million Chloride 176 Amount of Extraction Liquid 2 mL Micrograms of Chloride ___ Area Extracted 12.25 cm2 Micrograms per cm2 chloride ___ 77. Complete the following chart:
Conductivity of sample 120 µS/cm Conductivity of blank 8.7 µS/cm Net Conductivity of sample ___
78. Convert 35 µS/cm to surface chloride concentration using the formula on Page 3-147.
___________________
79. A pH of 10 is considered ___________________. 80. A pH of 3 is considered ___________________.
Module Three: Surface Preparation- Methods, Industry Standards and Inspection Supplemental Reading List
- Good Painting Practice: SSPC Painting Manual, Volume 1, 4th Edition (SSPC Item #02-14)
- Systems and Specifications: SSPC Painting Manual, Volume 2, 2005 Edition (SSPC Item #04-13)
- Surface Preparation Specifications and Practices (SSPC Item #05-03)
- SSPC-VIS 1 Guide and Reference Photographs for Steel Surfaces Prepared by Dry Abrasive Blast Cleaning (SSPC Item #02-12)
- SSPC-VIS 3 Guide and Reference Photographs for Steel Surfaces Prepared by Hand and Power Tool Cleaning (SSPC Item #04-07)
- SSPC-VIS 4 Guide and Reference Photographs for Steel Surfaces Prepared by Waterjetting (SSPC Item #01-05)
- SSPC-VIS 5 Guide and Reference Photographs for Steel Surfaces Prepared by Wet Abrasive Blast Cleaning (SSPC Item #01-06)
Module Four: Practical Arithmetic for the Coatings Inspector
Module Four reviews practical math skills used by the coatings inspector. Coating inspectors frequently need to apply basic math skills to everyday inspections. This module provides a review of common arithmetic associated with coatings inspection, including: converting percentages to decimal format; calculating square footages; calculating volume and converting ounces/gallon to percentage of thinner addition; converting VOC values; converting temperatures; and converting units of measurement for surface profile depth and paint thickness (mils to microns and back). A special session on calculating coating material quantities based on theoretical and practical coverage rates is included in this module.
Learning Outcomes
At the completion of this module you should be able to:
- Apply practical arithmetic to calculations relating to everyday jobs Apply Practical Arithmetic to Calculations Relating to Everyday Jobs
Arithmetic can be one of the more challenging aspects of coatings inspection that an inspector must employ on a project. Those challenged by mathematics simply throw up their hands and give up, rather than working through the formulas to generate the correct value(s), or they may rely on others to perform calculations for them. This module helps inspectors to become more comfortable with mathematics and describes the steps necessary to perform basic calculations.
An inspector should always be equipped with a working calculator to make the calculations easier and faster, and to avoid making simple mathematical errors. Recognize however, that if an incorrect value (or the incorrect form of a value) is inadvertently entered into the calculator, the answer will be wrong despite using the correct formula. So take your time and double check all entries. The old phrase says “practice makes perfect” and replication helps. If you are unfamiliar with any of the mathematics described in this module, practice the examples over and over. You can even substitute your own numbers in the examples to help gain confidence in application of the formulas. Finally, recognize that there is always more than one way to arrive at the correct answer. This module describes commonly used methods, but other methods or procedures may be used, as long as the final answer is the same.
Module Four: Practical Arithmetic for the Coatings Inspector
Workshop: Arithmetic for Protective Coatings Inspector
Instructions
Using the basic arithmetic skills taught in Module 4, solve each of the Problem Sets below. Remember to use your calculator to avoid making simple math errors. You may select the US standard or the metric exercises, depending on the prevailing system used. Problem Set 1: Averaging Values
You have collected the following surface profile measurements. Calculate the average of each area, then average all of the areas together.
Area 1 Area 2 Area 3 Area 4 Area 5 50 microns 40 microns 76 microns 42 microns 44 microns 75 microns 43 microns 80 microns 58 microns 71 microns 62 microns 49 microns 57 microns 55 microns 56 microns Area 1 Area 2 Area 3 Area 4 Area 5 2 mils 1.6 mils 3 mils 1.7 mils 1.7 mils 3 mils 1.7 mils 3.1 mils 2.3 mils 2.8 mils 2.4 mils 2 mils 2.2 mils 2.2 mils 2.2 mils
Average of Area 1 ______________ Average of all Areas _______________ Average of Area 2 ______________
Average of Area 3 ______________ Average of Area 4 ______________ Average of Area 5 ______________
Problem Set 2: Averaging Values
You have collected the following coating thickness measurements. Calculate the average of each area, then average all of the areas together.
Area 1 Area 2 Area 3 Area 4 Area 5 205 microns 181 microns 305 microns 256 microns 311 microns 312 microns 233 microns 295 microns 214 microns 298 microns 199 microns 241 microns 287 microns 277 microns 283 microns Area 1 Area 2 Area 3 Area 4 Area 5 8 mils 7.1 mils 12 mils 10.1 mils 12.2 mils 12.3 mils 9.2 mils 11.6 mils 8.4 mils 11.7 mils 7.8 mils 9.5 mils 11.3 mils 10.9 mils 11.1 mils
Average of Area 1 ______________ Average of all Areas _______________ Average of Area 2 ______________
Average of Area 3 ______________ Average of Area 4 ______________ Average of Area 5 ______________
Problem Set 3: Converting Percentages to Decimal Format
A two-coat exterior coating system has been specified and the products have been delivered to the project site. You have elected to calculate target wet film thickness and the maximum amount of thinner that can be added to each. The coating manufacturer lists the volume solids content and the allowable thinner as a percentage. You will need to convert each of the percentages to decimal.
Decimal Format Allowable percentage of thinner for the primer: 15% _____________
Volume solids content of primer: 65% _____________
Allowable percentage of thinner for the topcoat: 5% _____________ Volume solids content of topcoat: 52% _____________
Problem Set 4: Calculating Area
A cylindrical ground storage tank contains four (4) shell rings. Each shell ring is made from eight (8) steel plates measuring 3 meters (10 feet) by 7 meters (23 feet). The interior and exterior of the tank is to be coated (excluding the interior floor and interior ceiling, and the exterior roof, which all appear to be in good condition). The tank owner has asked you to verify that the contractor has ordered enough coating, so you will need to first calculate the total area of the shell rings to be coated. Use the space below to show the steps you took to arrive at the final answer.
Total area of shell rings to be coated: ________________
Show steps here:
Problem Set 5: Calculating Area
The project specification for surface preparation of steel I beams in the fabrication shop requires three (3) surface profile measurements every 30 square meters (100 square feet) of prepared surface. There are two sizes of I beams on the project:
Beam Size A: 0.5 meter (18 inch) flanges (2.54 cm [1 inch] thick) 2 meter (6 foot) web
18 meters (60 foot) beam length
12 – stiffeners, each 2 meters (6 foot) x 10 cm (4 inches) wide Beam Size B: 0.5 meter (18 inch) flanges (2.54 cm [1 inch] thick)
2.5 meter (8 foot) web
24 meters (80 foot) beam length
16 – stiffeners, each 2 meters (6 foot) x 10 cm (4 inches) wide Total square meters (square feet) for Beam Size A: ______________
Total square meters (square feet) for Beam Size B: ______________
If the total project involves 12 beams of Size A and 15 beams of Size B, now many surface profile measurements are required for the project? ___________________
Use the space below to show the steps you took to arrive at the answers. You may also want to draw and label the two beams with the dimensions for each to help visualize the sizes.
Problem Set 6: Calculating Volume of Coating
A three-component product has been selected for use on a project. Component A is 11 liters (3 gallons) in a 19 liter (5 gallon) container. Component B is 3.8 liters (1 gallon) in a 3.8 liter (1 gallon) container. Component C is 0.5 liter (1 pint) in a 1 liter (1 quart)
container. What is the total volume of coating once all components are combined together?
Problem Set 7: Calculating Volume of Thinner
According to the manufacturer’s product data sheet for the three-component coating in Problem Set 6, the coating must be thinned 15%. What is the total volume of thinner that must be added to the coating?
Problem Set 8: Converting Milliliters/Liter to Percentage
According to the manufacturer’s product data sheet, the recommended amount of thinner to add to a coating is 50 milliliters per liter of coating. If the mixed volume of coating is 5 liters, how many milliliters of thinner will be added?
Problem Set 9: Converting Ounces/Gallon to Percentage
According to the manufacturer’s product data sheet, the recommended amount of thinner to add to a coating is 13 ounces per gallon of coating. If the mixed volume of coating is 5 gallons, how many ounces of thinner will be added?
What percentage of thinner will be added to the coating? Problem Set 10: Converting VOC Content
The local air quality regulations for a recoating project do not allow coatings containing VOC in excess of 2.1 lbs./gallon. The product data sheet that the coating manufacturer provided for the solvent-borne primer only reports the VOC content in grams per liter, which is 250 grams/liter. Can the coating be used on the project?
Based on the VOC content reported on the product data sheet, will the contractor be able to thin the coating?
Problem Set 11: Converting VOC Content
A steel fabrication shop that also performs surface preparation and primer application work is located in an area with very strict air pollution regulations. Coatings used by the fabrication shop cannot exceed 375 grams/liter VOC. The shop wants to use a primer that contains 3.9 lbs./gal. VOC. Can the primer be used by the shop?
Problem Set 12: Converting Temperature
According to the coating manufacturer’s product data sheet, the air temperature must be maintained between 40°F and 100°F during application. The air temperature is 34°C. Can coating application work continue? After answering yes/no, indicate the actual
temperature in °F.
Problem Set 13: Converting Temperature
According to the coating manufacturer’s product data sheet, the coating storage area must be maintained between 10°C and 49°C. The air temperature in the storage area is 125°F. Does the storage temperature conform to the manufacturer’s requirements? After answering yes/no, indicate the actual temperature in °C.
Problem Set 14: Converting Units Used to Express Coating Thickness and Surface Profile Depth
The coating specification requires a 2.0-3.5 mil surface profile depth. The actual surface profile depth ranges from 63.5 to 83.8 microns. Does the area meet the specification? After answering yes/no, indicate the actual surface profile range in mils.
Problem Set 15: Converting Units Used to Express Coating Thickness and Surface Profile Depth
The coating specification requires the primer and intermediate coats to be a combined thickness of 203-305 microns. The thickness of the combined coats ranges from 6 to 10 mils. Does the area meet the specification? After answering yes/no, indicate the actual coating thickness range in microns.
Problem Set 16: Calculating Coating Material and Thinner Requirements A three-coat system has been specified for protecting a structure estimated to be 2,323 square meters in area. The volume solids content is 75% for the primer, 56% for the intermediate coat and 46% for the topcoat. The specified thickness is 75-100 microns for the primer, 125-178 microns for the intermediate coat and 50-75 microns for the topcoat. The contractor will need to reduce the primer and intermediate coatings by 10% with Thinner No. 2 and will need to thin the topcoat by 5% using Thinner No. 4. Mixing and application losses are estimated to be 20% for each coating, and the surface profile is expected to consume 15% of the primer. Based on this scenario, complete the chart below:
Inquiry Enter Answer Here
Quantity of primer required (in liters)
Quantity of intermediate coating required (in liters) Quantity of topcoat required (in liters)
Quantity of thinner required for primer & intermediate coatings (in liters)
Quantity of thinner required for topcoat (in liters)
Show the metric version of the formula for calculating coating coverage here:
Problem Set 17: Calculating Coating Material and Thinner Requirements A three-coat system has been specified for protecting a structure estimated to be 25,000 square feet in area. The volume solids content is 75% for the primer, 56% for the
intermediate coat and 46% for the topcoat. The specified thickness is 3-4 mils for the primer, 5-7 mils for the intermediate coat and 2-3 mils for the topcoat. The contractor will need to reduce the primer and intermediate coatings by 10% with Thinner No. 2 and will need to thin the topcoat by 5% using Thinner No. 4. Mixing and application losses are estimated to be 20% for each coating, and the surface profile is expected to consume 15% of the primer. Based on this scenario, answer the questions below:
Inquiry Enter Answer Here
Quantity of primer required (in gallons) Quantity of intermediate coating required (in gallons)
Quantity of topcoat required (in gallons) Quantity of thinner required for primer & intermediate coatings (in gallons)
Quantity of thinner required for topcoat (in gallons)
Show the US Standard version of the formula for calculating coating coverage here:
Module Four: Practical Arithmetic for the Coatings Inspector Quiz 4
1. Average the following set of surface profile measurements: 3.5, 3.7, 2.9, 3.1, 4.0 _____________
2. Convert 39% to decimal format. _____________
3. Calculate the amount of thinner to add to 10 gallons of mixed coating to be reduced 20%. _____________
4. Calculate the area of a square that is 4.5 feet x 13.6 feet. _____________ 5. Calculate the area of an I-beam that is 40 feet in length, has 12” wide flanges, a 48” web, and 8 stiffeners (4” wide x 48” long). _____________
6. Calculate the exterior surface area of a tank that is 45 feet in height and 90 feet in diameter.
_________________________________________________________
Calculate the volume of water the tank in Question 6 will hold.
_________________________________________________________ 7. Convert 2.4 pounds/gallon VOC to grams/Liter.
_____________________________________ 8. Convert 64oF to oC. ______________
9. Convert 275 micrometers to mils _______________
10. Calculate the quantity of primer required to coat 15,000 square feet of blast cleaned steel, based on the following data:
Specified Dry Film Thickness: 3-5 mils Volume Solids Content: 84% Mixing/Application Loss Estimate: 25% Surface Roughness Loss Estimate: 20%
Recommended Thinner Addition: One pint per gallon
Module Four: Practical Arithmetic for the Coatings Inspector Supplemental Reading List
Module Five: Coating, Mixing, Thinning and Application: Equipment Overview and Inspection Techniques
Module Five explains the inspection of coating mixing, thinning, and application. Experts claim that poor application, along with inadequate surface preparation, cause the majority of all industrial coating failures. This module provides an overview of the various methods used to apply coatings, including conventional (air) spray, airless spray, HVLP, air-assisted airless spray, and brush & roller. The advantages and limitations of each method, along with proper technique will be emphasized. Module Five will continue with the inspection of mixing, thinning, and coating application processes, including measuring ambient conditions, witnessing and documenting mixing and thinning procedures, wet and dry film measurements, use of the Tooke Gage (destructive testing) to determine the thickness of individual layers in a coating system,
pinhole/holiday detection, adhesion, and coating hardness and curing tests. Learning Outcomes
At the completion of this module you should be able to:
- Describe the procedures associated with proper mixing, thinning, and application of industrial coatings
- Define the SSPC standards for coating application
- Describe the role of the coating inspector on a coatings project
- Use MSDS and product data sheets to verify safe and proper mixing, thinning, and application of coatings
- Describe the inspector’s role regarding coating material receipt and storage - Measure and record ambient conditions and surface temperature
- Calculate Wet Film Thickness - Measure Wet Film Thickness
- Verify accuracy of nondestructive coating thickness gages - Measure coating thickness using nondestructive gages
- Describe the SSPC standard for measurement of coating thickness - Measure coating thickness using destructive methods
- Detect pinholes and holidays - Measure coating adhesion - Evaluate coating cure - Measure coating hardness
- Describe methods used to verify intercoat cleanliness
Describe the Procedures Associated with Proper Mixing, Thinning, and Application of Industrial Coatings
Proper coating mixing procedures are one of the most important steps in the successful installation of a protective coating system. The procedures for blending single
component materials is straightforward and needs little instruction other than ensuring the material is homogeneous by mixing all of the settled pigment and solids materials into the liquid. Conversely, the mixing procedures for multiple component materials can be more complex, and often requires the individual responsible for mixing the coatings and the inspector to read and comprehend the product data sheets.
Similar to mixing, thinning of a coating material is perceived to be rather straightforward and requires little explanation. However, the type and amount of thinner added to the coating impacts the volatile organic compound (VOC) content, the target wet film thickness of the coating, and over thinning or under thinning a coating can adversely affect the application and performance characteristics. Therefore, thinning of a coating is an important area to discuss and is equally important to verify that it is done properly. Transferring the coating materials from the can to the surface can be accomplished in a number of ways. Factors that should be considered when deciding on an application method include the size and configuration of the surfaces to be coated, the desired or required transfer efficiency, the type of coating, environmental regulations, the proximity to other operations/conditions, the specification and the coating manufacturer’s
recommendations.
The seven methods of coating application that we will describe in this module include: 1. Brushes, rollers, and daubers
2. Airless spray
3. Conventional (air) spray
4. High Volume Low Pressure (HVLP) spray 5. Air-assisted airless spray
6. Metallized spray
7. Plural component spray
Define the SSPC Standards for Coating Application
SSPC has two main standards that pertain to coating application, including SSPC PA 1 (Shop, Field and Maintenance Painting of Steel) and SSPC PA 2 (Measurement of Dry Coating Thickness with Magnetic Gages).
Describe the Role of the Coating Inspector on a Coatings Project
The inspector’s role in a coating project varies, depending on the requirements of the specification. The more common checkpoints include:
1. performing materials receipt inspection and documentation
2. witnessing and verifying (documenting) coating mixing and thinning procedures 3. measuring and documenting ambient conditions and surface temperature
4. calculating and measuring wet film thickness 5. measuring dry film thickness nondestructively 6. verifying re-coat times
7. assessing intercoat cleanliness 8. assessing cure
9. assessing coating hardness
10. performing pinhole or holiday detection 11. adhesion testing
