Application Failure Series – Paint Surface Cratering

Why Does Cratering in Paint Occur?

Painting can often be an underestimated step in securing the longevity of a plant or manufacturing facility.  Its benefits are obvious, but there is room for error during application.  And these errors and imperfections painted are typically much more difficult to remedy after the application has been installed, often leaving the only option to scrape and repaint.  Due to application failure, pepainting can be tedious and frustrating.  However if you are careful from the start, it is possible to avoid waste time and money.

Any successful painting job is reflected in its surface.  A high quality job will have a consistent finish. And that qualify typically relies on the preparation of the substrate.  Even the application of an expensive coat does not guarantee a high quality finish. If minor details or steps are overlooked, they can result in application errors and mistakes later on. Sometimes, problems can appear within a few months of the application. From paint blistering to flaking, paint blocking to cratering, there are several problems that can arise in interior paint applications.

A type of painting defect, cratering gives an uneven finish to the painted surface. This unevenness is due to presence of small round indentations on the wall surface, just like a crater or fish eye. When paint is applied on the surface, it is possible that tiny bubbles are formed on the surface. But, when these bubbles break, they form circular depressions in form of craters. There are several reasons for cratering in paint surfaces, it includes –

  • Presence of air pockets in the topcoat paint, especially in fast drying topcoats.
  •  Excessive rolling or brushing the surface while applying paint coat.
  • Applying paint rapidly over the surface, especially, with use of roller brushes. It also happens if roller brush of wrong nap length is used.
  • Presence of foreign materials incompatible with the surface in the substrate or paint.  Contaminants include fine dust, polishing agents, minute particles and others.
  • Using an incompatible reducer, additives or thinner for the paint.
  •  Application of semi-gloss or gloss coating over an unsealed surface.
  • Presence of impurities in paint or paint substrate due to improper storage or transportation.
  • Using paint that is more than year old or using cheap, low quality paints.

Both paint bubbles and cratering can be avoided if proper care is taken right from choosing paint to its application process. Now, you can easily find home and industrial painting solutions that are designed to overcome this problem. These paints are designed so that bubbles burst and flow smooth while drying. When the bubbles are absent altogether, cratering is significantly reduced, leaving a nice smooth application.