The Most Common Reasons Coatings or Paint Fail
Coating and paint failure is a significant issue as it can end up costing you as a manufacturer or contractor time, money, and even your reputation for quality. Often when your coating fails you may have to conduct a coating failure analysis, recall product, and more. Being able to know what causes coating and paint failure will allow you to effectively use appropriate practices to ensure you reduce the chance of coating or paint failure. There are six primary reasons that coatings fail which we will cover so you can better know how to prevent coating or paint failure.
First Reason Coatings or Paint Fail – Improper Surface Preparation
The first major source of paint or coating failure is improper surface preparation. Proper surface preparation can involve cleaning, chemical pre treatment, and/or surface roughening. Each step of surface preparation can require unique consideration. Surface roughening is commonly accomplished through power tools, hand tools, or sandblast equipment depending on the preparation standard you need to achieve. The preparation standard is usually dictated by the coating provider that you are working with. You can learn the general preparation standards by reviewing either NACE or SSPC standards, both are commonly referenced. To properly determine if you have an adequate preparation of your surface to reduce risk of coating or paint failure you can employ a variety of resources. Common options include SSPC VIS 1 Guide, Depth Micrometers, and replica tape. Ideally, you will want to consider verification with a few methods to ensure proper preparation of the surface has been achieved. You can also coordinate with a coatings provider to ensure that you have properly prepared the surface (this can be helpful when first using a new coating). A replica tape is often used as it will provide a record that you can use in your documentation showing the profile that was found at the time you prepped the surface.
Second Reason Coatings or Paint Fail – Improper Coating Selection
The type of coating you need will depend on a variety of factors including the substrate that the coating is applied to, the desired performance length of the coating, and the environmental conditions which the coating will have to withstand (will it have to resist corrosion due to water or acid? or protect the substrate from other exposure?). To ensure you have found an appropriate coating you can coordinate with a coatings company. Depending on the application it may require that the coating company perform tests like UV exposure testing or other tests.
Third Reason Coatings or Paint Fail – Improper Application
Application includes a variety of factors from environmental factors to the actual way you apply the coating. A great resource to ensure you are properly applying the coating is the technical data sheet which will typically cover all the critical factors that you should consider when applying a coating. Common factors that are important include the temperature and humidity during application, the proper mixing of the coating, the mil thickness of coating you apply, and the equipment you use to apply. If temperature and humidity control is critical for your paint application you may need a paint booth that will allow for environmental control or be selective about when you can apply coating. You also need to consider that the coating is properly applied so that there are not issues like sags, runs, or similar issues associated with over or under application of coating.
Fourth Reason Coatings or Paint Fail – Improper Recoating or Curing of the Coating
As mentioned previously the technical data sheet provides a lot of detail about proper application of the coating. Another area of common oversight is how the coating is cured once it has been applied. This is particularly critical in multi-coat or coating systems with multiple coatings applied for enhanced protection. You want to ensure that the coating has had sufficient time to cure prior to placing it in the field. Similarly, if you plan on applying a second coat or additional coating to your product you want to verify what the correct degree of cure is prior to applying any additional coating or paint. If a second coat or coating will be applied, you will also want to verify if any special preparation is required prior to applying the second coat or additional coating. Your coating representative should address all these details or help answer questions so that you can ensure proper coating performance.
Fifth Reason Coatings or Paint Fail – Accidental damage to the coating system
A final area that can result in coating failure is when damage occurs to the coating system, This can be due to anything from natural accidents to interference by man or even handling your product before it has had adequate time to cure. If the coating system is damaged through any of these mechanisms it can create a situation where the coating system will stop providing the benefits it was designed to.
Ultimately coating failure is a complex issue that stems from a variety of problems ranging from selecting the wrong coating, to improper application of the coating, to improper preparation of the surface. To ensure success it can be helpful to consider working with a coating provider, equipment provider, and depending on the application a coating inspection service or having your own worker certified. By coordinating with these different groups and having a strong understanding of coating application from coating selection to surface preparation to the application you can reduce the risk of experiencing a coating or paint failure.