Industrial coatingsare designed to protect surfaces under tough conditions, but even high-performance products can fail if not applied and maintained correctly. Three of the most common coating failure modes are blistering, cracking, and delamination. These issues not only undermine the protective function of the coating but also create costly rework and safety hazards. This guide provides an authoritative troubleshooting approach for fixing blistering, cracking, and delamination, with a focus on how Marvel Industrial Coatings’ products and services can prevent and resolve these failures. The insights are geared toward contractors, engineers, facility managers, and anyone responsible for purchasing or applying industrial coatings, especially in demanding environments.

In the sections below, we break down each failure type, explore their causes, and outline practical fixes. You’ll also find a handy comparison table summarizing causes and solutions for quick reference. Throughout, we highlight Marvel’s advanced polyurea coatings, primers, and expert support that can help you avoid these problems. By understanding coating failure troubleshooting and leveraging the right products and expertise, you can ensure long-lasting, high-performance protection for your assets.

Common Coating Failures and Their Causes

Before diving into specific failures, it’s important to note that most coating problems stem from a few fundamental issues: inadequate surface preparation, unfavorable environmental conditions during application, improper application techniques, or using a coating ill-suited for the service conditions. These factors can lead to loss of adhesion, moisture intrusion, or stress build-up in the coating – manifesting as blisters, cracks, or peeling. In fact, weak adhesion due to poor surface prep is a root cause behind many issues (blistering, cracking, peeling, etc.). Similarly, applying coatings outside the recommended temperature or humidity range can trap moisture or solvents, resulting in blistering and poor curing. Understanding these underlying causes will inform how we fix and prevent failures.

Let’s examine each failure mode in detail:

Blistering in Coatings: Causes and Fixes

Blistering appears as bubbles or raised bumps on the coating surface, sometimes filled with liquid or air. It’s often used interchangeably with “bubbling,” and both indicate that something (moisture, solvent, or gas) is trapped under or within the coating film. Blistering not only looks bad but also compromises the coating’s protective seal, leading to premature corrosion if not addressed.

Common causes of blistering include:

• Surface contamination: If the substrate isn’t clean (e.g., contains dust, oil, or soluble salts), the coating may adhere to the contaminants instead of the surface. Moisture drawn to these spots can create osmotic pressure, forming blisters. For example, soluble salt contamination on steel can draw water through the paint film, generating pressures that cause blisters under the coating.
   

• Solvent or moisture entrapment: Coating too thickly or recoating too soon can trap solvents that haven’t fully evaporated. The same happens if paint is applied when humidity is too high or onto a damp surface. Moisture gets sealed in. Later, heat (sunlight, process heat, etc.) will drive that moisture out as vapor, creating bubbles and blisters in the film. Polyurea coating problems often relate to this: polyurea sets fast, but it’s sensitive to moisture during curing. In humid climates or on green concrete that hasn’t dried, you might see small bubbles or blisters due to moisture vapor under the coating.
   

• Application in the wrong conditions: Temperature extremes can cause blistering. Applying coatings in cold weather slows curing and can trap moisture; inadequate cure leads to poor adhesion, so the coating may later blister or peel. Conversely, applying in very hot conditions can skin the coating over too quickly, trapping solvents or air. These trapped pockets form blisters, especially if the coating was applied in direct sun or on a hot surface.
   

How to troubleshoot and fix blistering:

• Identify and remove the blisters: Inspect the coating to see how deep the blisters go. Typically, you’ll need to abrade or cut out the blistered spots, down to a sound layer. If liquid comes out, dry the area thoroughly. Small blisters can be sanded out; larger affected areas may require scraping or grinding the coating off.
   

• Eliminate moisture and contamination: Before recoating, ensure the substrate is clean and dry. Use appropriate cleaning methods (solvent wipe, pressure wash, etc.) to remove oils, dirt, or salts. For enclosed areas, blowers or dehumidifiers can help dry out moisture or aid solvent evaporation. It’s critical to only reapply coatings under recommended environmental conditions (typically, moderate temperature and humidity). This prevents new blisters from forming.
   

• Apply a suitable primer if needed: Primer can be a game-changer in preventing blisters on porous or moisture-prone surfaces. A quality primer seals the substrate and blocks moisture vapor transmission. It also improves adhesion, so the topcoat is less likely to lift. Marvel Industrial Coatings offers multi-purpose epoxy primers that create a strong barrier on concrete, wood, or metal, reducing the risk of bubbles “pushing through” from underneath. (For instance, Marvel’s primers are designed to enhance adhesion and performance of polyurea topcoats on various substrates.)
   

• Recoat following best practices: Once prep and priming are done, re-apply the coating, making sure to follow the proper film thickness and recoat timing. Do not exceed the recommended wet film thickness (to allow solvents to escape) and observe recoat windows so that each layer fully cures. Use multiple thin coats if necessary instead of one heavy coat. By ensuring correct surface preparation and application conditions, you greatly reduce the chance of blistering recurring.
   

If blisters keep appearing across a large area despite these fixes, it might indicate a pervasive moisture issue (like moisture coming through a concrete slab or water ingress behind a steel panel). In such cases, consult Marvel’s technical experts for a deeper diagnosis. We may suggest moisture mitigation steps (e.g. installing a vapor barrier or using a specialty coating system) or perform on-site testing to pinpoint the moisture source.

Marvel’s team is experienced in solving blistering in coatings. With proper surface assessment, our Marvel primers and application guidance, even challenging substrates can be coated blister-free. For example, on high-humidity projects, Marvel can provide fast-curing polyurea formulations and techniques to minimize moisture entrapment. The key is a combination of the right product and process control.

Cracking in Coatings: Causes and Fixes

Cracking refers to breaks in the hardened coating film. Cracks can range from fine “checking” lines to deep fissures that expose the substrate. They often indicate that the coating was unable to accommodate stresses, whether from its own curing process or from movement/expansion of the underlying material. Cracked coatings not only look like dried mud or alligator skin, but they also lose their barrier protection – allowing water and chemicals to seep in through the cracks.

Common causes of cracking include:

• Coating applied too thick or too hard: Excessive film thickness is a major contributor to cracking. As a thick coating cures, it can shrink and develop internal stress, leading to crack formation. Likewise, using a very high-hardness, inflexible coating in an environment where some flex is needed will make it prone to crack. This is often seen as “mud cracking” – deep, irregular cracks resembling dried mud, caused by a relatively inflexible coating applied overly thick. Coatings also can crack if they cured at elevated temperature or too quickly, making them more brittle.
   

• Thermal expansion and substrate movement: Industrial equipment and structures expand and contract with temperature changes. If a coating lacks sufficient flexibility or elongation, it cannot stretch or compress along with the substrate, and thus it breaks apart over time. For example, imagine a concrete tank or steel roof that gets hot in the sun and cold at night – an overly rigid coating on it may develop fissures due to this daily expansion/contraction cycle. Limited coating flexibility, combined with thermal or mechanical stresses, is a probable cause of cracking and checking failures.
   

• Aging and UV exposure: Some coatings become more brittle as they age or when exposed to UV radiation (sunlight). Epoxies, for instance, can chalk and embrittle over years, making them crack. Polyurea, being more UV resistant in aliphatic formulations, performs better here, but if an aromatic polyurea is used outdoors without a UV topcoat, it could eventually experience surface cracking or chalking. (Marvel addresses this by offering aliphatic polyurea topcoats for UV stability and long-term flexibility on exposed surfaces.)
   

How to troubleshoot and fix cracking:

• Assess the extent of cracking: If cracks are isolated (e.g., only the topcoat is cracked but the primer is intact), you might get away with spot repairs. However, deep or widespread cracking usually means the coating is failing and should be removed. Attempting to simply recoat over active cracks is not wise, as the cracks can propagate through the new layer.
   

• Remove and recoat when necessary: The general fix for significant cracking is to remove the affected coating completely and apply a new system. This can be done by sanding, abrasive blasting, or mechanical means, depending on the surface and coating type. Removal ensures you eliminate all brittle material and can start fresh with a coating that will adhere and perform properly.
   

• Choose a flexible, appropriate coating: To prevent recurrence, select a coating with sufficient flexibility and elongation for the service conditions. This is where polyurea coatings shine – pure polyureas have high elongation (often 200% or more) and remain flexible even in extreme temperatures. They are designed to adapt to substrate expansions and contractions without cracking or peeling. For instance, Marvel’s polyurea systems combine high tensile strength with elongation up to 250%, allowing them to bridge small movements and handle thermal stress that would crack conventional epoxies. If your current coating cracked because it was too brittle, consider upgrading to a Marvel polyurea or hybrid coating engineered for flexibility.
   

• Apply at the recommended thickness: Always follow the manufacturer’s specified dry film thickness (DFT) per coat. If a coating is applied too thick in one pass, the risk of cracking increases. It’s better to do multiple thinner coats with proper curing between them. Marvel’s technical data sheets provide guidance on maximum film builds. For example, an elastomeric polyurea might allow a high build in one go, whereas a rigid epoxy should be built up in layers. Sticking to these guidelines helps avoid internal stresses that cause cracks.
   

• Address underlying movement or stress: If cracking was due to substrate movement (like a flexing floor or vibrating equipment), you may need to adjust the system. This could mean incorporating a primer or intermediate layer that can absorb stress, using a reinforcing mesh or fabric in the coating, or simply using a more elastomeric topcoat. In scenarios of drastic movement, an engineered solution from Marvel’s experts may be required (for example, a polyurea expansion joint filler or a flexible membrane underlayer in the system). The goal is to accommodate the movement so the topcoat stays intact. Marvel’s Industrial Coatings team can recommend the right combination of products for such cases.
   

By selecting high-performance flexible coatings and applying them correctly, you can achieve a crack-resistant protective layer. Marvel’s 100% pure polyurea coatings are particularly suited for areas that see frequent thermal cycling or mechanical impact. They cure to a tough but flexible film that resists both impact and cracking. Remember that even the best coating can crack if misused (for example, any coating will crack if applied twice as thick as intended). So prevention is about pairing the right product with best practices.

Delamination (Peeling): Causes and Fixes

Delamination is when a coating peels off either from its substrate or between coating layers. It’s often seen as large sheets or flakes of coating coming loose, sometimes in patches. This is a serious failure mode because it indicates loss of adhesion. The coating is no longer bonded and thus offers little protection. Delamination can occur in isolated spots or across an entire surface if something went fundamentally wrong in the application.

Common causes of coating delamination include:

• Inadequate surface preparation: This is the number one cause of delamination. If the surface was smooth, glossy, or contaminated before coating, the paint film may never truly “bite” into it. Sub-par surface prep (for instance, painting over a chalky old coating or over mill scale/rust on steel) leads to poor bonding. The new coating might initially hide the problem, but it will lift off easily under stress. A classic example is applying a coating on steel without proper abrasion: a smooth, shiny steel substrate (or one with a thin layer of oil or rust) offers very little for the coating to grip, so peeling is almost inevitable. Delamination defects are often related to a smooth or poorly bonded undercoat or substrate.
   

• Exceeding recoat window / poor intercoat adhesion: Many industrial coatings require you to apply the next coat within a certain time frame (recoat window) or else perform additional surface prep. If this is overlooked, the layers might not chemically bond, resulting in the topcoat later peeling off the base coat. Contamination between coats (like dust settling on a primer before topcoat, or even amine blush on an epoxy) can also interfere with intercoat adhesion. In one case study, a polyurea topcoat applied over an epoxy primer started delaminating because the primer was allowed to fully cure without profile and no sanding was done. Essentially the polyurea was on a smooth epoxy film and peeled off in sheets. Even layers of the same material can delaminate from each other if proper recoat procedures aren’t followed (polyurea sprayed over an older polyurea without sanding or primer can separate under use).
   

• Moisture or vapor pressure under the coating: Similar to blistering, if water gets underneath the coating (say through a crack or at an unsealed edge) and then heats up, it can push the coating off. This is more a secondary cause. The primary issue was likely poor edge sealing or a holiday (break) in the coating. But it’s worth noting that corrosion under a coating will also cause delamination; rust builds up and pushes the coating away (often appearing as blistering or peeling with rust beneath). In all cases, however, if the coating had excellent adhesion, it would be much harder for moisture or rust to force it off. It’s when adhesion is marginal that these forces easily cause peeling.
   

How to troubleshoot and fix delamination:

• Evaluate the bond across the surface: If one area peeled, it’s likely others are close behind. Inspect the coating adhesion in multiple spots (a simple tape pull test or light scrape can tell if the coating is loosely attached). Often, you’ll find large sections that can be lifted off because the adhesion was universally poor. In general, it’s safest to assume you need to remove and recoat any areas that are peeling or at risk, since adhesion cannot be restored once lost.
   

• Remove the coating completely if necessary: Effective repair of delamination usually means stripping the coating back to a sound substrate or layer. All loose paint must be scraped off. If the root cause was poor surface prep, the underlying substrate likely needs to be properly prepared now (e.g. abrasive blasting of steel to a specified anchor profile, or thorough sanding of a glossy fiberglass surface, etc). For concrete, it may involve grinding to remove laitance. The aim is to create a clean, roughened surface for the new coating to adhere to. Marvel Industrial Coatings always emphasizes surface prep: even the best coating won’t hold long on a dirty or slick surface. Marvel’s team can advise on the right prep method (profiling standard, cleaning technique) for your project. We also supply surface prep equipment and training to our certified applicators to ensure this critical step is done right.
   

• Use appropriate primers and adhesion promoters: After prepping, applying a quality primer is often the best insurance against future delamination. Primers are formulated to bond tenaciously to the substrate and to the topcoat, effectively bridging the two. They can also block any remaining contaminants and promote a chemical/mechanical bond. For instance, Marvel offers Marvel Multi-Purpose Primer, an industrial-grade primer for all surfaces (concrete, steel, aluminum, wood, etc.) that significantly improves the chemical and mechanical bond in a coating system. As Marvel notes, choosing the right primer can make a “world of difference” for long-term adhesion. In scenarios where you cannot abrasive-blast or thoroughly scuff a surface (say you’re coating over an existing sound paint), Marvel’s Adhesion Promoter primer is designed to help new polyurea coatings bond to an un-sanded surface. Always follow primer instructions for drying times and overcoating. A properly primed surface will greatly reduce the chance of peeling.
   

• Address intercoat adhesion issues: If the delamination happened between layers (e.g., between coats of polyurea, or between a primer and topcoat), make sure to observe the recoat windows and surface prep between coats going forward. When reapplying, if you’re going over an existing cured layer, sand or abrade the old coating to create a profile, or use a specialty recoat primer. Marvel’s NP (No-Prep) Recoat Primer was developed exactly for this purpose. It lets you recoat polyurea beyond the normal recoat window without peeling. By simply wiping it on and letting it dry, you can bond fresh polyurea to an aged coating, saving you from having to strip everything when doing repairs or additions. This is an invaluable solution for contractors who need to extend a project or fix a section long after the original application.
   

• Quality control and testing: After the repair, it’s wise to do an adhesion test on a sample area to ensure the problem is truly solved. For critical infrastructure, Marvel’s consultants can perform pull-off adhesion tests to verify the new system meets required adhesion (typically measured in PSI). Our experts also help by documenting surface prep and environmental conditions. (Marvel’s On-Site Consultation service provides detailed reports of surface prep, environmental readings, and coating thickness to guarantee everything is done according to specification.)
   

Delamination can be daunting (seeing large sheets of coating coming off) but with proper remediation steps, you can restore the protection. The combination of proper surface preparation, the right primer, and adherence to application guidelines is the formula for success. Marvel Industrial Coatings backs its primer and coating systems with extensive testing and real-world performance to ensure they “stay stuck” when applied correctly. Our motto: a coating system is only as good as its bond to the substrate. So we leave nothing to chance in achieving a strong adhesion. If you’re ever unsure, reach out to Marvel’s technical support (available 24/7) for troubleshooting assistance.

Quick Reference Table: Coating Failures, Causes & Solutions

Below is a comparison of the three failure types, summarizing their typical causes and recommended fixes. Use this table as a handy guide during any coating failure troubleshooting.

(References for the data in this table: Adv. Polymer Coatings blog; Marvel Industrial Coatings guides; VFI technical article.)

As the table shows, blistering, cracking, and delamination have distinct triggers, but they often interrelate. For instance, blisters (if large) can lead to delamination, and cracks can let moisture in that causes blisters or peeling. At the core, proper adhesion and appropriate coating selection are the common themes in prevention: keep the unwanted things (moisture, contaminants) out and ensure the coating can handle the stresses of its environment.

Preventing Coating Failures: Best Practices and Marvel’s Solutions

While troubleshooting existing problems is valuable, the ultimate goal is to avoid coating failures altogether. By implementing best practices and leveraging Marvel Industrial Coatings’ expertise, you can significantly extend the life of your coatings without blisters or peeling.

Here are some prevention tips and how Marvel helps you implement them:

• 1. Always start with proper surface preparation: As emphasized, surface prep is the foundation of a successful coating job. Follow the standards (e.g., SSPC/NACE guidelines for steel blast cleanliness, concrete profiling, etc.) appropriate for the coating system. Remove all rust, old loose paint, grease, and ensure the surface profile (roughness) meets the coating manufacturer’s spec. Marvel aids in this step by providing training and documentation on surface prep. For example, our School of Polyurea training program teaches contractors the correct methods of substrate preparation and how to choose the right primer for each substrate. We even offer on-site consulting where Marvel experts will supervise surface preparation and verify conditions before you coat. This kind of diligence up front prevents adhesion issues that cause blistering or delamination later.
   

• 2. Use high-quality primers and adhesion promoters: Primers are not an optional step in industrial coating. They are essential for difficult surfaces or critical service. Marvel’s line of Marvel Primers is formulated to tackle common adhesion challenges. For instance, Marvel Multi-Purpose Primer creates a robust bond on concrete, steel, wood, and more, which is especially useful if you have a substrate that’s both porous and smooth (like wood or aluminum). For situations where you cannot abrasive blast, our Marvel Adhesion Promoter can be applied to improve coating bonding without mechanical profiling – useful for quick turnarounds or coating over sound old paint when blasting isn’t feasible. And as mentioned, Marvel NP Recoat Primer extends coating recoat times, preventing intercoat delamination when you need to add another layer outside the standard window. By selecting the right primer, you increase adhesion efficiency and thus avoid the majority of blistering/peeling problems down the road.
   

• 3. Control the application environment: Environmental conditions during coating application and curing must be within the acceptable range. This includes ambient temperature, surface temperature, humidity, and dew point. Aim to apply coatings at moderate temperatures (e.g. 50–90°F, unless the product is formulated for cold application) and low-to-moderate humidity. Avoid painting if the surface is colder than the dew point (to prevent condensation) or if the substrate is excessively hot (causing too-fast drying). Marvel helps clients plan their projects around weather, and we offer products like fast-curing polyureas that can tolerate a broad temperature range – but even those have limits that we’ll guide you on. If you must coat in cold conditions, Marvel may recommend tenting and heating the area, or using winter-grade catalysts. If you’re in a high-humidity environment, we might suggest dehumidification or moisture-tolerant primers to mitigate issues. By adhering to manufacturer specs for conditions, you’ll avoid many issues such as coating blistering due to moisture or poor cure.
   

• 4. Follow application procedures and mix ratios accurately: Many coating failures (bubbles, soft spots, poor adhesion) can result from improper mixing or application technique. Always mix multi-component coatings in the exact ratio specified – an off-ratio mix (too much resin or hardener) can result in a coating that doesn’t fully cure or bonds poorly. Ensure your spray equipment is properly proportioning in case of plural-component systems. Marvel provides equipment training and troubleshooting support for all our spray-applied products, so you can be confident the coating is applied correctly. Additionally, maintain the recommended spray technique: correct gun distance, overlap, and pass speed to achieve even thickness. Our Marvel technical reps often visit job sites to assist new applicators in mastering these techniques. Proper application avoids defects like cratering, sags, and holidays that could lead to failure later.
   

• 5. Select the right coating formula for the job: Not all coatings are equal, and using the wrong type can cause premature failure. For example, a standard epoxy might chalk and crack in outdoor UV exposure, whereas an aliphatic polyurea or polyurethane topcoat would remain stable. If you need a coating to handle chemical exposure, ensure it’s rated for those chemicals or it might blister/peel when in contact. Marvel’s product portfolio includes polyurea, polyurethane, epoxy, and other specialty coatings – each suited to certain environments. We work closely with customers to match the coating to the service conditions (temperature swings, UV, chemicals, abrasion, etc.). Our experts might recommend, for instance, a 100% solids pure polyurea for a secondary containment lining (due to its chemical resistance and flexibility), or a polyurethane topcoat over polyurea for an outdoor tank (for UV resistance). Using the right system prevents failures that occur when a coating is out of its element.
   

• 6. Take advantage of Marvel’s support and expertise: Marvel Industrial Coatings distinguishes itself with a robust support system for our clients. We don’t just sell you coating products; we partner with you to ensure they succeed in the field. This means 24/7 technical support hotlines, on-site consultation services, and a wealth of resources (manuals, videos, and training classes on troubleshooting). For example, if you encounter an unexpected issue like blistering or delamination, Marvel will help analyze the cause (perhaps via sample analysis or site inspection) and then guide you to the proper fix – whether that’s a primer application, a change in equipment settings, or a tweak in technique. Our “The Difference is Marvel” motto reflects our commitment to being there for customers at every step. By consulting with Marvel’s experts at the project planning stage, you can preempt many problems. We can review your project specs, recommend the best coating system, and even train your applicators on that system. This proactive approach is the surest way to achieve a defect-free coating application that meets your performance expectations.
   

By implementing these best practices, the likelihood of blistering, cracking, or delamination is dramatically reduced. Industrial coatings, when properly applied, perform for many years with minimal maintenance. And in those rare cases something does go wrong, having Marvel Industrial Coatings as a partner means you have immediate access to solutions and advanced products to set it right.

Frequently Asked Questions (FAQ)

To wrap up, here are some common questions about coating failures and troubleshooting, answered in a concise, schema-friendly Q&A format.

Q: What causes blisters to form under a coating, and how can I prevent it?
A: Blisters (or bubbles) are usually caused by moisture or solvents trapped in or beneath the coating film. If the substrate is damp, or if paint is applied too thickly or in very humid conditions, liquid can get encapsulated. Later, heat draws this liquid out as vapor, forming blisters. Contaminants like oil or salt on the surface can also attract moisture and create osmotic blisters. To prevent blistering, always start with a clean, dry surface and use proper surface preparation to remove contaminants. Apply coatings within the recommended environmental conditions (not too cold or humid). Avoid heavy coats that could trap solvents – it’s better to do two thin coats with adequate drying time than one thick coat. Using a primer on porous surfaces (like concrete or wood) is a great preventative step; the primer will seal the surface and block moisture from coming through, as well as improve adhesion. In summary, dry, clean substrate + proper application = no blisters in most cases. If blisters do appear, it’s a sign something was off in the process, and you’ll need to remove the affected area, eliminate the cause (e.g. moisture), and recoat properly.

Q: We applied a coating and now it’s cracking – what went wrong?
A: Cracking in a coating often indicates the coating is too brittle or too thick for the conditions. One common cause is applying the coating at an excessive thickness, which leads to shrinkage stress and “mud-crack” patterns as it cures. Another cause is using a coating that lacks flexibility on a surface that moves or expands (for example, a rigid epoxy on a metal that sees temperature swings). The coating can’t stretch, so it fractures when the substrate expands. High curing temperatures or catalyzers can also make a coating cure too fast/hard and become prone to cracking. To fix the issue, you typically need to remove the cracked coating and reapply a more suitable system. Prevention tips: ensure you’re not exceeding the specified film build; if you need a thick layer, use a product designed for high-build applications in multiple passes. Also, choose a coating with the right elasticity – for surfaces with thermal expansion or vibration, an elastomeric polyurea or polyurethane will resist cracking far better than a glass-hard epoxy. For instance, polyurea coatings have high elongation (often over 200%) so they can flex with substrate movements without cracking. In practice, if you see a coating starting to crack, address it sooner than later. Small cracks (checking) can sometimes be sanded and overcoated with a more flexible topcoat. But widespread cracking means a restart with the proper material. Marvel’s experts can help diagnose whether the issue was thickness, wrong product choice, or environmental, and recommend a crack-resistant solution for your needs.

Q: What are the main coating delamination causes, and how do I avoid peeling paint?
A: Delamination (peeling) happens when a coating loses adhesion. The primary causes are almost always related to poor bonding: inadequate surface prep or poor intercoat adhesion. If the substrate wasn’t properly prepared – say it was smooth metal with no profile, or dirty concrete with dust – the coating might only be tenuously holding on, and it will peel off under stress or even just over time. Likewise, if you apply a second coat after the first coat has fully cured without roughening it, the new coat may not stick (this is an intercoat adhesion failure). Contaminants between layers (like if someone walked on a primed surface and left dirt before topcoating) can also cause peeling between coats. To avoid delamination, the mantra is “clean and rough”: the surface should be clean of any loose material or contaminants, and have a suitable roughness (anchor pattern) for the coating to grab onto. Always follow the coating manufacturer’s surface prep specification (e.g., SSPC-SP10 near-white blast for a heavy-duty system on steel, or an acid etch or mechanical grind for concrete). Also, don’t skip the primer if one is recommended – primers are formulated to bond to the substrate and will dramatically improve adhesion of the system. Between coats, respect the recoat time; if you exceed it, you may need to lightly sand the surface or apply a bonding primer (like Marvel’s recoat primer) to ensure the next layer sticks properly. In summary, most peeling problems can be traced back to not following these practices. If you have a coating peeling off now, you’ll likely need to remove it, do the prep correctly, and reapply the system as per specs. Going forward, implementing strict surface prep and application procedures will keep your coatings tightly adhered for the long haul.

Q: Are polyurea coatings prone to any special problems (and how can Marvel help)?
A: Polyurea is a advanced coating technology with many advantages – extremely fast cure, high flexibility, and strong resistance to chemicals and abrasion. However, like any material, it has its nuances. One well-known polyurea coating problem is its sensitivity to moisture during application. Because polyurea reacts and cures so quickly, any moisture present (in the concrete or in the air) can cause foaming or bubbles. For example, applying polyurea on a concrete slab that hasn’t fully dried can result in blistering and even delamination of the coating due to moisture vapor pressure. Another consideration: pure polyurea, if aromatic, is not UV stable – prolonged sun exposure can cause it to discolor or chalk (though it generally won’t delaminate just from UV). Marvel addresses that by providing aliphatic polyurea topcoats or recommending polyaspartic topcoats for projects with heavy UV exposure. In terms of adhesion, polyurea will stick extremely well if the surface is prepared and primed correctly – its bond strength is excellent on blasted steel or properly primed concrete. But if an applicator gets complacent (e.g., skips sanding between coats, or sprays polyurea on a smooth glossy paint), it can still peel off – as was documented in a case where polyurea peeled because the metal surface wasn’t profiled. Marvel helps avoid these pitfalls through our training and support: we emphasize moisture testing of concrete (and offer moisture-tolerant primers when needed), we supply Marvel primers specifically to promote adhesion on tricky substrates, and we educate applicators on following recoat windows to ensure polyurea layers fuse properly. Additionally, our technical team can customize formulations (gel time, etc.) for unique challenges – for instance, a slower gel polyurea for a very humid environment, or an accelerator for cold weather. In short, while polyurea has a few special considerations, Marvel Industrial Coatings has the knowledge and product range to overcome them. With the right practices, polyurea coatings should perform problem-free, delivering long-term protection without blistering or peeling.

Q: When a coating fails, how do I decide whether to repair it or replace it completely?
A: This is a great question that often comes up for facility managers. The decision depends on the extent of the failure and the root cause. If the failure (be it blisters, cracks, or peeling) is localized – say a small section of a tank has blistered because of an unknown contaminant, or a floor coating has a few cracks in high-stress areas – you can usually perform a localized repair. This involves removing the coating in that area and blending a repair patch, often extending a bit into the surrounding intact coating and feathering the edges. However, if the failure is widespread or systemic, it’s usually more cost-effective and reliable to redo the coating entirely. For example, if an entire coat of paint is peeling off a large portion of a structure due to poor surface prep, it’s likely that most of it will eventually release – so it’s better to strip it and start over with proper prep, rather than chasing peeling spots endlessly. Another factor is the cause: if you haven’t addressed the root cause, a patch repair will fail again. Marvel’s approach is to conduct a failure analysis (if needed) to determine why the coating failed. Once we know the cause, we can say if a localized fix will hold or not. We also look at the age of the coating – if it’s near the end of its expected life, a full replacement might make sense rather than piecemeal fixes. Keep in mind the downtime and logistics too: sometimes doing one big recoat is less disruptive than constant small repairs. In summary, spot repair is suitable for minor, contained issues and when the remaining coating is sound; full replacement is warranted when the failure is extensive, the existing coating is compromised in many areas, or fundamental application errors require a reset. Marvel can assist in making this call by inspecting the site and perhaps performing adhesion tests on the intact areas – if those pull off easily, that tells us a full recoat is needed. Our goal is to ensure you get a solution that lasts, so we weigh the options and recommend the approach with the best long-term outcome.

In conclusion, blistering, cracking, and delamination in industrial coatings are problems that can be solved – and more importantly, prevented – with the right knowledge and products. By understanding the failure mechanisms and following the guidelines above, you can troubleshoot existing issues and greatly reduce future coating failures.

Marvel Industrial Coatings is here to support you at each step, from product selection and training to on-site troubleshooting and long-term maintenance. We pride ourselves on being a solutions-driven partner – when you succeed, we succeed. If you’re facing any coating challenges or planning a project that demands high performance, we encourage you to reach out to our team for personalized guidance.

Ready to Ensure Your Coatings Never Fail? – Contact Marvel

Protect your assets with confidence. Connect with Marvel’s coating experts today to discuss your project requirements, schedule a failure analysis, or get a quote on our industry-leading polyurea coatings and primers. With Marvel’s advanced products and technical support by your side, blistering, cracking, and delamination will be problems of the past.

Contact Marvel Industrial Coatings for a consultation or call (844) 658-0022 to speak with a technical representative. Let’s make your next coating project a long-lasting success. 

References

1. AMPP (formerly NACE/SSPC), Surface Prep Standards

2. U.S. Bureau of Reclamation, Guide to Protective Coatings, Inspection, and Maintenance - Second Edition (PDF)

3. ASTM D1640/D1640M-14(2022), Standard Test Methods for Drying, Curing, or Film Formation of Organic Coatings

4. Pfaff, F.A. & Gelfant, Frederick. (1997). Osmotic blistering of epoxy coatings on concrete. 14. 52-64. 

5. ASTM D714 – Standard Test Method for Evaluating Degree of Blistering

6. KTA-Tator Inc. – Common Causes of Blistering and Bubbling in Industrial Coatings. Industry reference on moisture/osmotic blister mechanisms and pressures.