ASTM G62: The Technician’s Guide to High-Voltage Holiday Detection of Pipeline Coatings
CTA Article Written By Jim Kunkle, PCS
Jim Kunkle is a technical principal, industry educator, and recognized voice in protective coatings, corrosion mitigation, and cathodic protection. With a career spanning field operations, product training, digital transformation, and industry advocacy, Jim has built a reputation for translating complex integrity challenges into clear, actionable guidance for technicians, inspectors, and asset owners.
His experience covers the full lifecycle of corrosion control, from surface preparation and coating system selection to CP fundamentals, interference challenges, and pipeline integrity best practices. Jim has worked closely with contractors, engineers, and owner‑operators across the energy, pipeline, and industrial sectors, helping teams strengthen their understanding of coating performance, AC mitigation, CP interactions, and real‑world failure modes.
Holiday detection isn’t just another box to check during coating QA/QC, it’s one of the most decisive steps in protecting buried and immersed assets from premature failure. For corrosion technicians, ASTM G62 remains a frontline tool because it addresses the most fundamental truth in corrosion control: if steel is exposed, corrosion will find it.
Even the best coating systems, applied by the most skilled crews, can hide small discontinuities that escape the naked eye. A pinhole the size of a grain of sand can become a high‑current demand point, a moisture trap, or the starting point of underfilm corrosion. Once buried, insulated, or placed in service, those defects become exponentially harder and more expensive to detect and repair. That’s why holiday detection is not merely a quality check; it’s a risk‑reduction strategy.
ASTM G62 matters because it gives technicians a standardized, repeatable way to find these defects before they become failures. High‑voltage holiday testing, in particular, is the only practical method for verifying the integrity of thicker coatings such as fusion‑bonded epoxy (FBE), abrasion‑resistant overcoats (AROs), tank linings, and pipeline field joint coatings. When technicians follow G62 correctly, they’re not just confirming coating continuity, they’re validating the entire corrosion protection system, including cathodic protection performance and long‑term asset reliability.
In today’s industry, where operators demand longer coating life, fewer failures, and tighter regulatory compliance, the technician’s role in holiday detection has never been more critical. ASTM G62 gives the field a common language, a common method, and a common expectation: find every discontinuity, repair it, and verify the repair before the asset disappears underground or goes into service.
What ASTM G62 Covers: Scope and Purpose
ASTM G62 sits at the center of modern coating quality control because it defines how technicians verify the continuity of nonconductive protective coatings using high‑voltage or low‑voltage holiday detection. Its purpose is straightforward but critical: to locate any discontinuity, any pinhole, void, thin spot, or defect, that exposes the substrate and compromises corrosion protection.
For corrosion technicians, the value of G62 is that it provides a standardized, repeatable method for detecting these flaws across a wide range of coating systems. Whether you’re inspecting fusion‑bonded epoxy on a pipeline, an epoxy lining inside a tank, or a thick urethane system on structural steel, G62 gives you the framework to confirm that the coating is truly continuous before the asset is placed into service.
The scope of ASTM G62 is intentionally broad. It applies to coatings that are electrically insulating and thick enough to require voltage-based testing. It covers two primary methods: low‑voltage wet sponge testing and high‑voltage spark testing, and outlines the equipment, procedures, and safety considerations associated with each. What it does not do is specify acceptance criteria, repair procedures, or coating thickness requirements. Those come from project specifications, coating manufacturers, and related standards.
In practice, G62 is the technician’s roadmap for detecting holidays in the field. It ensures that testing is performed consistently, safely, and with the correct voltage for the coating thickness. By defining the “how,” ASTM G62 supports the broader corrosion control strategy, ensuring that coatings perform as intended and that no hidden defects are left behind to become tomorrow’s failures.
Understanding the Two Test Methods
ASTM G62 is built around two distinct approaches to holiday detection: Method A (low‑voltage wet sponge) and Method B (high‑voltage spark testing). For corrosion technicians, knowing when and how to use each method is essential. These aren’t interchangeable tools; they’re purpose‑built for different coating systems, thicknesses, and service environments. Understanding the differences is what separates a routine inspection from a reliable one.
Method A: Low-Voltage Wet Sponge Testing
Method A is the simplest form of holiday detection, and it’s designed for thin, nonconductive coatings, typically below 20 mils (0.5 mm). The principle is straightforward: a moistened sponge carries a low-voltage current across the surface. When the sponge encounters a discontinuity, the current passes through the exposed steel and triggers an alarm.
Technicians use Method A when:
● The coating is thin (e.g., decorative coatings, some tank linings, certain epoxies)
● The specification calls for low-voltage testing
● The risk of damaging the coating with high voltage must be avoided
Advantages:
● Simple, safe, and easy to operate
● Minimal risk of damaging the coating
● Ideal for small areas or touch-up verification
Limitations:
● Cannot detect holidays in thicker coatings
● Requires the surface to be dry enough to avoid false positives
● Slow for large surface areas
In the field, Method A is often used for small components, thin-film systems, or as a secondary verification step. But for most industrial coatings, especially those used in corrosion-critical environments, technicians rely on Method B.
Method B: High-Voltage Spark Testing
Method B is the backbone of ASTM G62 and the method most corrosion technicians associate with “holiday detection.” It uses a high-voltage pulse or continuous DC output to detect discontinuities in thicker coatings, typically 20 mils (0.5 mm) and above. This includes fusion-bonded epoxy (FBE), abrasion-resistant overcoats (AROs), polyurethane linings, tank linings, and pipeline field joint coatings.
Technicians use Method B when:
● The coating is thick or multi-layered
● The asset is critical (pipelines, tanks, submerged structures)
● The specification requires high-voltage testing
● The coating manufacturer provides a voltage-to-thickness chart
Advantages:
● Highly effective at detecting even microscopic holidays
● Fast coverage of large surface areas
● Essential for pipeline, tank, and structural steel coatings
Limitations:
● Incorrect voltage can damage the coating
● Requires proper grounding and technician training
● Not suitable for uncured or moisture-contaminated coatings
Why Method B dominates field work: High-voltage spark testing is the only practical way to verify continuity in the thick, high-performance coatings used in modern corrosion control. When technicians set the correct voltage and follow ASTM G62 procedures, Method B provides a reliable, repeatable assessment of coating integrity before the asset is buried, insulated, or placed into service.
Why Understanding Both Methods Matters
ASTM G62 doesn’t just tell technicians how to test, it tells them which method is appropriate for the coating system in front of them. Using the wrong method can lead to missed defects, coating damage, or false confidence in a system that isn’t truly protected.
For corrosion technicians, mastering both methods ensures:
● Accurate detection of discontinuities
● Compliance with project specifications
● Protection of the coating system from unnecessary damage
● Confidence that the asset is ready for service
Equipment Requirements and Calibration
Holiday detection is only as reliable as the equipment in the technician’s hands. ASTM G62 doesn’t just outline testing methods, it establishes the expectations for the tools, electrodes, grounding, and voltage verification needed to perform the test correctly. For corrosion technicians, understanding the equipment is just as important as understanding the coating system itself.
Holiday Detection Equipment: What Technicians Use in the Field
Holiday detection equipment generally falls into two categories, aligned with the two ASTM G62 methods:
Low-Voltage Wet Sponge Detectors (Method A)
These units are simple, compact, and designed for thin-film coatings. They typically include:
● A low-voltage power source
● A moistened sponge electrode
● A ground lead
● An audible/visual alarm
They’re ideal for small components, thin coatings, and areas where high voltage could damage the film.
High-Voltage Spark Testers (Method B)
These are the workhorses of industrial coating inspection. They include:
● A high-voltage power supply (pulse DC or continuous DC)
● A variety of electrode types (spring, brush, rubber, conductive neoprene)
● A ground cable and clamp
● Voltage adjustment controls
● Audible/visual holiday indicators
Pulse DC units are common in pipeline and tank work because they reduce the risk of coating burn-through while maintaining sensitivity.
Choosing the Right Electrode
Electrode selection is not cosmetic, it directly affects test accuracy.
Common electrode types include:
● Spring electrodes:
Ideal for pipes, field joints, and curved surfaces
● Brush electrodes:
Good for flat surfaces and large areas
● Rubber/neoprene electrodes:
Used for linings and smooth surfaces
● Wire loop electrodes:
Useful for irregular geometries
The electrode must maintain continuous contact with the coating surface. Poor contact leads to missed holidays, false readings, and inconsistent results.
Grounding: The Most Overlooked Step
Proper grounding is essential for both safety and accuracy. Without a solid ground connection:
● Holidays may not register
● Voltage may arc unpredictably
● The detector may give false positives or false negatives
Technicians should always:
● Attach the ground clamp directly to the substrate
● Verify continuity between the clamp and the steel
● Avoid grounding through coated or insulated surfaces
A poor ground is one of the most common causes of inaccurate holiday detection.
Voltage Selection and Calibration
Voltage is the heart of ASTM G62 Method B. Too little voltage and holidays go undetected. Too much voltage and the coating can be damaged, creating defects that weren’t there before.
Technicians must:
● Set voltage based on coating thickness
● Follow coating manufacturer voltage charts
● Verify voltage output before testing
● Re-check voltage if equipment is dropped, bumped, or exposed to moisture
ASTM G62 provides guidance on voltage selection, but most projects rely on manufacturer-specific charts to ensure accuracy.
Calibration considerations include:
● Using a certified voltmeter or built-in verification device
● Checking output at multiple voltage levels
● Documenting calibration results in inspection reports
A technician who cannot verify voltage cannot verify coating integrity.
Environmental and Surface Conditions
Holiday detection equipment is sensitive to environmental conditions. ASTM G62 emphasizes that testing should only occur when:
● The coating is fully cured
● The surface is dry and clean
● Humidity is within acceptable limits
● No conductive contaminants (salt, dust, moisture) are present
Environmental factors can cause:
● False positives (moisture bridging the electrode)
● False negatives (coating too soft or uncured)
● Coating damage (testing too early)
Technicians must evaluate conditions before energizing the detector.
Technician Readiness: The Human Factor
Even the best equipment fails without a trained operator. Technicians must understand:
● How to set and verify voltage
● How to maintain electrode contact
● How to interpret alarms
● How to distinguish true holidays from surface irregularities
● How to document findings accurately
ASTM G62 provides the framework, but technician skill ensures the test is meaningful.
Preparing the Surface and Coating for Testing
Holiday detection is only effective when the coating and surface are properly prepared. ASTM G62 emphasizes that testing must occur under the right conditions: not too early, not too late, and never on a contaminated or improperly cured surface. For corrosion technicians, this stage is where accuracy is won or lost. A perfectly calibrated detector means nothing if the coating isn’t ready to be tested.
Ensuring the Coating Is Fully Cured
One of the most common technician errors is testing too early. High‑voltage testing on an uncured coating can:
● Burn through the film
● Create artificial holidays
● Produce false positives
● Void the coating manufacturer’s warranty
Technicians should always:
● Follow the coating manufacturer’s cure schedule
● Consider temperature, humidity, and film thickness
● Verify cure using recommended methods (e.g., solvent rub tests, hardness checks)
A coating that feels dry is not necessarily cured. ASTM G62 assumes the coating has reached a state where voltage testing will not damage it.
Surface Cleanliness: Eliminating Contaminants
Holiday detection requires a clean, dry surface. Contaminants can interfere with the test by conducting electricity across the surface or masking defects.
Technicians must ensure the coating is free of:
● Moisture
● Dust and debris
● Salt contamination
● Grease or oils
● Mud, soil, or jobsite residue
Moisture is especially problematic. Even a thin film of water can create a conductive path that triggers false alarms or prevents proper grounding.
Grounding the Substrate
Before any voltage is applied, technicians must confirm that the substrate can be properly grounded. Without a solid ground:
● Holidays may not register
● Voltage may arc unpredictably
● The detector may behave inconsistently
Grounding best practices include:
● Clamping directly to bare steel
● Avoiding coated or insulated surfaces
● Verifying continuity with a multimeter if needed
A reliable ground is the foundation of accurate holiday detection.
Environmental Conditions: When Not to Test
ASTM G62 stresses that environmental conditions can make or break a test. Technicians should avoid testing when:
● The coating is wet or dew is present
● Humidity is excessively high
● The surface temperature is below the dew point
● Rain, fog, or condensation is likely
● The coating is too hot or too cold
Environmental conditions can cause:
● False positives (moisture bridging)
● False negatives (soft or uncured coating)
● Coating damage (testing in extreme temperatures)
A quick dew point check and surface temperature reading can prevent costly mistakes.
Technician Pre‑Test Checklist
Before energizing the detector, technicians should confirm:
● The coating is fully cured
● The surface is clean and dry
● The correct voltage has been selected
● The electrode is appropriate for the geometry
● The ground connection is secure
● Environmental conditions are acceptable
● All safety precautions are in place
This checklist is not optional, it’s the difference between a reliable test and a misleading one.
Why Preparation Matters
Holiday detection is a precision task. Even though the equipment looks rugged and the process seems straightforward, the accuracy of the test depends heavily on preparation. ASTM G62 assumes technicians are working on a surface that is ready for inspection. When preparation is rushed or skipped, the test becomes unreliable, and the risk of coating failure increases.
Proper preparation ensures:
● Accurate detection of true holidays
● Protection of the coating from unnecessary damage
● Compliance with project specifications
● Confidence that the asset is ready for service
Performing the Test: Step-by-Step Technician Workflow
Holiday detection isn’t guesswork, it’s a controlled, repeatable process. ASTM G62 gives technicians the framework, but the workflow is what ensures accuracy in the field. This section breaks down the practical, technician-centered sequence for performing both low‑voltage and high‑voltage holiday detection safely and effectively.
Step 1: Verify Equipment Setup and Voltage
Before the electrode ever touches the coating, technicians must confirm that the detector is configured correctly.
For both Method A and Method B:
● Inspect cables, connectors, and electrodes for damage
● Confirm the ground cable is securely attached to bare steel
● Ensure the electrode is appropriate for the geometry
● Check battery levels or power supply status
For Method B (high voltage):
● Set the voltage based on coating thickness
● Verify output using a voltmeter or built‑in calibration device
● Document the voltage setting in the inspection report
This step prevents the two biggest technician errors: under‑voltage (missed holidays) and over‑voltage (coating damage).
Step 2: Establish a Reliable Ground
Grounding is the backbone of holiday detection. Without it, the detector cannot complete the circuit needed to identify discontinuities.
Technicians should:
● Clamp directly to exposed steel
● Avoid grounding through coated or insulated surfaces
● Confirm continuity if the ground path is questionable
● Re-check ground periodically during testing
A poor ground is the number one cause of false negatives in the field.
Step 3: Begin Testing with Controlled, Consistent Movement
Once voltage and grounding are confirmed, technicians begin sweeping the electrode across the coating surface.
Key practices:
● Maintain continuous contact between the electrode and the coating
● Move at a steady pace, typically 1–2 feet per second
● Overlap passes to ensure full coverage
● Avoid lifting the electrode during movement
For curved surfaces (e.g., pipe), spring electrodes must maintain full circumferential contact. For flat surfaces, brush or rubber electrodes provide uniform coverage.
Step 4: Identify and Confirm Holidays
When the detector encounters a discontinuity, it signals the technician with an audible alarm, visual indicator, or both.
Technicians must:
● Stop immediately when the alarm sounds
● Re-test the exact location to confirm the holiday
● Mark the defect clearly with a grease pencil, marker, or tape
● Document the location and size of the holiday
False positives can occur due to moisture, contaminants, or poor grounding, which is why confirmation is essential.
Step 5: Continue Systematic Coverage
Holiday detection must be methodical. Technicians should work in defined sections, ensuring no area is skipped.
Best practices include:
● Testing in lanes or grids
● Using natural boundaries (welds, edges, joints) as reference points
● Maintaining consistent sweep speed and electrode pressure
● Periodically verifying voltage and ground integrity
This systematic approach ensures complete coverage and defensible inspection records.
Step 6: Document Findings and Prepare for Repairs
ASTM G62 does not specify repair procedures, but it does require accurate identification of discontinuities. Once testing is complete:
Technicians should:
● Record all holiday locations
● Note voltage settings, equipment type, and environmental conditions
● Communicate findings to the coating or repair crew
● Ensure repairs are completed according to project specifications
Documentation is critical for traceability and quality assurance.
Step 7: Re-Test After Repairs
Every repaired holiday must be re-tested. This is non-negotiable.
Technicians must:
● Allow the repair material to cure fully
● Re-test the area using the same voltage and method
● Confirm that no additional holidays are present
● Update inspection records to reflect successful repair
Re-testing ensures that the coating system is continuous and ready for service.
Why the Workflow Matters
Holiday detection is not just about finding defects, it’s about preventing future failures. A disciplined workflow ensures:
● No areas are missed
● No defects go unverified
● No coating is damaged by improper testing
● No asset is buried or placed into service with exposed steel
ASTM G62 provides the standard, but technicians provide the precision. When the workflow is followed correctly, holiday detection becomes one of the most powerful tools in corrosion prevention.
Interpreting Results and Required Actions
Holiday detection is not just about finding defects, it’s about understanding what those defects mean and taking the right corrective actions before the asset is buried, insulated, or placed into service. ASTM G62 provides the framework for identifying discontinuities, but it’s the technician’s responsibility to interpret the results accurately and ensure that every holiday is addressed. This section translates the standard into practical, technician-centered decision-making.
What Counts as a Holiday Under ASTM G62
A holiday is any discontinuity in the coating that exposes the substrate or allows electrical current to pass through the film. This includes:
● Pinholes
● Voids
● Thin spots
● Craters or fisheyes
● Mechanical damage (scratches, gouges, impact marks)
● Missed areas or incomplete coverage
If the detector signals, the technician must assume the coating is compromised at that location.
ASTM G62 does not differentiate between “minor” and “major” holidays, a holiday is a holiday, and every one of them must be repaired.
Distinguishing True Holidays from False Positives
Not every alarm is a true defect. Technicians must confirm each indication by re-testing the exact spot.
Common causes of false positives include:
● Moisture on the coating surface
● Contaminants such as dust, salt, or debris
● Poor grounding
● Testing too early (coating not fully cured)
● Electrode skipping or intermittent contact
A confirmed holiday will trigger consistently when the electrode passes over it. If the signal cannot be repeated, technicians should investigate environmental or equipment issues before proceeding.
Documenting Holiday Locations
Accurate documentation is essential for quality control and traceability. Technicians should:
● Mark each holiday clearly with a grease pencil, marker, or tape
● Record the location using grid references, weld numbers, or stationing
● Note the size and nature of the defect
● Include voltage settings, equipment type, and environmental conditions in the report
Good documentation ensures that repair crews know exactly where to work and that inspectors can verify repairs later.
Required Actions: Repairing Holidays
ASTM G62 does not prescribe repair methods that fall to the coating manufacturer and project specifications. However, the industry expectation is universal:
“All holidays must be repaired before the asset is placed into service or buried.”
Typical repair actions include:
● Cleaning the defect area
● Feathering edges if needed
● Applying the approved repair material (patch kit, liquid epoxy, heat-shrink sleeve, etc.)
● Allowing the repair to cure fully
● Re-testing the repaired area
Skipping repairs or burying unrepaired holidays is never acceptable in corrosion-critical applications.
Re-Testing After Repairs
Every repair must be verified using the same method and voltage used during the initial test. This ensures:
● The repair material has fully cured
● The defect has been eliminated
● No new holidays were introduced during repair
● The coating system is continuous and compliant
Re-testing is not optional, it is the final quality gate before the asset is approved.
When Results Indicate Larger Problems
Sometimes holiday detection reveals more than isolated defects. Patterns of holidays may indicate:
● Improper surface preparation
● Incorrect coating thickness
● Application errors (e.g., poor mixing, environmental contamination)
● Equipment malfunction during coating application
● Coating system incompatibility
In these cases, technicians should escalate findings to supervisors or inspectors. A high density of holidays often signals systemic issues that require broader corrective action.
Why Interpretation Matters
Holiday detection is not just a pass/fail test, it’s a diagnostic tool. Proper interpretation ensures:
● Coatings perform as designed
● Cathodic protection systems are not overloaded
● Long-term corrosion risks are minimized
● Assets enter service with confidence
● Operators avoid costly failures and rework
ASTM G62 gives technicians the method, but interpretation is where experience, judgment, and attention to detail make the difference.
Safety Considerations for High-Voltage Testing
High‑voltage holiday detection is one of the most effective tools in a corrosion technician’s arsenal, but it also introduces real electrical, physical, and environmental hazards. ASTM G62 emphasizes safety throughout the standard, and for good reason: improper grounding, incorrect voltage, or careless handling can injure personnel, damage coatings, or create ignition risks in hazardous environments. This section translates those safety expectations into practical, technician-centered guidance.
Understanding the Hazards of High Voltage
High‑voltage spark testers can generate thousands of volts, even though the amperage is low. While the current is not typically lethal, it can still cause:
● Painful electrical shocks
● Involuntary muscle reactions
● Loss of balance or falls
● Burns from arc discharge
● Damage to sensitive equipment nearby
Technicians must treat the detector with the same respect given to any energized tool.
Personal Protective Equipment (PPE)
Proper PPE is non-negotiable. At a minimum, technicians should wear:
● Electrically insulated gloves
● Safety glasses or face shields
● Long sleeves and non‑flammable clothing
● Dielectric footwear
● Hearing protection when required
Loose clothing, jewelry, or conductive accessories should be removed before testing.
Safe Grounding Practices
Grounding is both a functional requirement and a safety measure. A poor ground can cause:
● Unpredictable arcing
● False readings
● Electrical feedback through the operator
● Damage to the coating or substrate
Safe grounding practices include:
● Clamping directly to bare metal
● Avoiding coated, insulated, or contaminated surfaces
● Verifying continuity before energizing the detector
● Keeping ground cables away from walk paths to prevent tripping
A secure ground is the technician’s first line of defense.
Avoiding Arc Damage and Coating Burn-Through
Incorrect voltage settings can cause the detector to arc through the coating, creating new defects. To prevent this:
● Always set voltage according to coating thickness
● Follow manufacturer voltage charts
● Verify voltage output before testing
● Avoid testing uncured or soft coatings
Arc damage is entirely preventable when technicians follow ASTM G62 and manufacturer guidance.
Working in Hazardous or Classified Areas
High‑voltage spark testing must never be performed in environments where flammable vapors, gases, or dusts may be present. The spark generated by the detector can ignite:
● Hydrocarbon vapors
● Solvent fumes
● Combustible dust
● Residual gases in confined spaces
Before testing, technicians must confirm:
● The area is gas‑free
● Ventilation is adequate
● Hot‑work permits are not required
● Atmospheric monitoring has been performed if needed
If there is any doubt, testing must be postponed until the area is verified safe.
Safe Handling of Cables and Electrodes
Holiday detection equipment includes long cables and energized electrodes that can create trip hazards or accidental contact points.
Technicians should:
● Route cables away from walkways
● Keep electrodes pointed downward when energized
● Never touch the electrode during operation
● De‑energize the unit before adjusting or changing electrodes
Simple cable management prevents many field accidents.
Environmental Awareness
Environmental conditions can increase safety risks. For example:
● Wet surfaces increase conductivity
● High humidity can cause unintended arcing
● Wind can blow debris into the electrode path
● Poor lighting can hide hazards or defects
Technicians must evaluate the environment before energizing the detector and adjust their approach accordingly.
Team Communication and Worksite Coordination
Holiday detection often occurs alongside coating crews, welders, or other trades. Clear communication prevents accidental contact with energized equipment.
Best practices include:
● Establishing a testing zone
● Informing nearby workers before energizing
● Using spotters when working in congested areas
● Keeping unauthorized personnel away from the test area
A well‑coordinated worksite is a safer worksite.
Why Safety Matters
High‑voltage holiday detection is safe when performed correctly and dangerous when it isn’t. ASTM G62 provides the technical framework, but technicians bring the judgment, awareness, and discipline needed to perform the test without incident.
Prioritizing safety ensures:
● Technicians avoid injury
● Coatings are not damaged
● Assets are tested accurately
● Worksites remain compliant
● Operators maintain confidence in inspection results
Safety is not an add‑on to holiday detection, it is integral to the process.
Takeaway: Why ASTM G62 Is a Technician’s Best Friend
Holiday detection may seem like a small step in the broader world of corrosion control, but ASTM G62 proves just how critical that step really is. For corrosion technicians, this standard is more than a procedure, it’s a safeguard, a quality gate, and a final assurance that the coating system will perform as intended once the asset is buried, immersed, or placed into service.
At its core, ASTM G62 empowers technicians to do what they do best: protect steel from the environments that want to destroy it. By providing a clear, repeatable method for detecting discontinuities, the standard ensures that no pinhole, void, or thin spot goes unnoticed. It reinforces the idea that corrosion prevention is not just about applying coatings, it’s about verifying them.
Holiday detection matters because:
● Coatings are never perfect, even when applied by skilled crews under ideal conditions.
● Small defects become big problems, once the asset is underground or in service.
● Cathodic protection cannot compensate for widespread coating holidays.
● Repairing defects before service is exponentially cheaper than repairing failures later.
● Technicians are the last line of defense, between a sound coating system and a preventable failure.
ASTM G62 gives technicians the tools, structure, and confidence to ensure coating integrity. It standardizes the process so that every test, whether on a pipeline, tank lining, field joint, or structural steel, is performed with the same level of rigor and reliability.
Ultimately, holiday detection is not just a task; it’s a commitment to asset integrity. When technicians follow ASTM G62, they’re not just finding defects, they’re preventing corrosion, protecting infrastructure, and upholding the professional standards that define the corrosion control industry.
Disclaimer
The views, interpretations, and technical opinions expressed in this article are solely those of James (Jim) Kunkle, PCS and are provided for educational and informational purposes within the protective coatings and corrosion control industries. They do not necessarily represent the official positions, policies, or commercial interests of ProCoatTec LLC, its partners, or any affiliated organizations.
While every effort has been made to ensure accuracy, the content should not be considered engineering advice, regulatory guidance, or a substitute for project‑specific evaluation by qualified corrosion professionals. Readers are encouraged to consult applicable standards, owner requirements, and certified corrosion specialists when making operational or integrity‑related decisions.
This article also highlights and supports the mission of the Corrosion Technician Association (CTA), an independent, technician‑driven association dedicated to elevating the skills, professionalism, and recognition of corrosion technicians and coatings professionals across all sectors. Any references to the CTA are intended to promote industry education and technician empowerment, and should not be interpreted as official statements made on behalf of the Association unless explicitly noted.
Neither ProCoatTec LLC nor the CTA assumes liability for actions taken based on the information presented. Use of this content is at the reader’s discretion and responsibility.
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