The Basics of Surface Preparation & Why It Matters

Choosing the right paint for your project is important, but the condition of the surface that you will apply it to is even more important. In fact, over 75% of all premature coating failures can be linked to improper or incomplete surface preparation.

The need to remove loose and flaky pieces is obvious. If painted over, those pieces will come off and so will the paint. Even vary small traces of dirt, grease or grime can interfere with the ability of the coating to stick to the surface so when a surface appears to be clean, it actually may not be. 

Looks Clean

Looks clean...


Solvent Wipe

...but solvent wipe reveals contamination

Regardless of the condition of the surface, the first step should be to wash and rinse it and follow minimal surface preparation steps. Minimal surface preparation is generally a two step procedure:

Brush   Step 1: Wash the surface with a cleaning solution or detergent to remove all dirt, grease, oil  and other surface contaminants. Rinse thoroughly.

 Scrape   Step 2: If loose rust or other loose materials are present such as a previous coating, remove using a mechanical method such as a wire brushes, sanding blocks, sanding wheels, stiff bristle brushes, paint scrapers and putty knives.

You will know when a surface is clean when only adherent material remains. Rust, mill scale, and paint are considered adherent if they cannot be removed by lifting with a dull putty knife using moderate pressure. This is considered sound rust. The surface is then ready to paint with a primer or a coating suitable for direct application to sound rust.