Polyguard recommends a NACE 3 blast finish whenever possible, but we also realize that surface preparation quality of field applied coatings is a major problem.

Several years ago, a joint industry project sponsored by US and Canadian pipeline companies was designed to address the problem that most external corrosion occurs at the girth weld, where coatings are field applied and subject to application quality problems.

A main objective of the study was to see how a group of 11 representative coatings performed under different levels of surface preparation quality.

The 11 coatings were applied using three different quality levels of surface preparation (abrasive blast, power tool, and hand tool).

Cathodic disbondment results showed that
RD-6 gave top performance, at all levels of surface preparation quality.