Surface cleanliness

There are two main international standards regarding steel surface cleanliness: the ISO Standard and the SSPC Standard.

ISO 8501-1 standards
It is a visual assessment relating to surface cleanliness. A number of preparation grades and the degree of cleaning are specified. The preparation grades are defined by written descriptions of the surface appearance after the cleaning operation, together with representative photographic examples.

SSPC standards
The SSPC (Society for Protective Coatings) Standards are used for specifying the degree of cleanliness of steel surfaces. SSPC has standard definitions and photographs for common methods of cleaning.

Surface roughness

The surface roughness of the steel surface is important to ensure a good adhesion of the coatings (set by an ISO standard). It is measured in microns and it shows the difference between the peaks and troughs in a steel surface. It is important because it will also affect the amount of paint to be used. With Blastrac closed circuit steel blasting machines, it is possible to easily achieve any roughness profiles by adjusting the abrasive mixture and speed of the machine.