Surface preparation

How to prepare a metallic surface before applying a coating?

A proper surface treatment is essential before you apply a coating. In many cases sand or grit blasting (abrasive blasting) is seen as the best method to prepare a metallic surface, to ensure a proper adhesion of the coating product to the surface.

But did you know that most coatings fail due to improper adhesion to the metallic surface. It is a general consensus amongst industry experts that 60% of this failed adhesion are a result of improper surface preparation before the coating is applied. Adhesion is determined by much more than just a treatment with grit or sand blasting.

The performance of protective coatings applied to steel is significantly affected by the state of the steel surface immediately prior to painting. The principal factors that are known to influence this performance are the presence of rust and mill scale, presence of surface contaminants, and The Surface Profile. Good practices around surface preparation are standardized in several ISO and AMPP (former SSPC) standards such as ISO21809-3.

New techniques for mapping surfaces and detecting contaminants allow for improvements. If you are interested, please download our positioning paper.

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