Early coatings failures can often be attributed to inadequate surface preparation. One of the most common steps skipped prior to applying a new coating is failing to effectively remove grease and oils from the substrate prior to painting.
Surfaces contaminated with grease and oils are far more likely to experience coating failures, anywhere from minor pinholes in the finish to full delamination of the coating. In order to reduce these adhesion issues, the grease and oils must be properly removed from the substrate prior to painting, as any residue left on the surface will cause significant problems down the line.
Think of it like this: when you’re frying an egg, you spray the pan with oil so the egg won’t stick. The same rings true for any substrate covered in oil or grease - the coating won’t stick!
Oils can get onto a surface many different ways. Whether the oil was placed on the surface intentionally as part of a manufacturing process, accumulated over time in industrial or marine environments, or was spilled accidentally, it's imperative that it's removed prior to applying new coatings.
One way that contractors will choose to remove grease and oil from substrates is with a Solvent Cleaning. Defined by AMPP’s SSPC-SP1 standard, solvent cleaning removes all visible oil, grease, dirt, and other soluble contaminants.
Since Solvent Cleaning does not have the ability to profile a surface, it is used in conjunction with other methods of surface preparation. While this is effective, it can often be time consuming and expensive.
Abrasive Blasting with Sponge Media, on the other hand, can remove coatings, oils, grease, chlorides, corrosion, and profiles the surface all in one step. Sponge Blasting lifts and removes oils and grease from the surface, ensuring proper removal of the contaminants, while creating the required profile for the coating.
Where grease and oils may be present on a substrate, it’s also important to check for invisible contaminants on the surface, such as chlorides. These substances can be just as harmful as visible contaminants, leading to rapid corrosion, impacting the integrity of both the coating and the structure itself.