When examining coating surfaces, what is the primary indicator of soluble salt contamination?

The primary indicator of soluble salt contamination on coating surfaces is indeed the presence of cracks in the topcoat. Soluble salts can attract moisture and can lead to the formation of corrosion underneath the coating. As the corrosion process continues, it generates pressure that can cause cracking in the topcoat, this is especially evident in the presence of moisture. These cracks serve as a telltale sign that soluble salts may be affecting the integrity of the coating.

Understanding this relationship is essential for inspectors, as identifying such cracks can help in determining whether surface preparation methods were adequate and if further remediation or inspection is required. Recognizing the effect of contaminants like soluble salts on the performance of protective coatings is crucial for maintaining the longevity and effectiveness of coatings in protecting surfaces from corrosion and other detrimental factors.