Solutions for Surface Tolerant Coating and Repair Applications

The corrosion process requires four key factors, an anode, a cathode an electrical connection, and an electrolyte. Removing any one of these factors will effectively halt corrosion. Polymeric coatings act as electrical insulators between the substrate and the electrolyte. The insulating barrier blocks the exchange of ions therefore halting corrosion of the metal substrate. Adhesion is critical to such a system. Good adhesion is achieved by a rough angular profile on the substrate to allow the polymer to physically grip the substrate. Common standards require at least a 3.0 mil angular profile and a NACE No. 2 /SSPC-SP 10 surface cleanliness. Unfortunately, in the field, it is difficult to meet all these requirements. New technology in polymeric materials has led to the development of epoxy-based products that can be applied onto wet and oily surfaces, therefore easing some of the typical surface preparation requirements. These materials are effective at displacing contaminants from the substrate via a strong electronic affinity with the metallic substrate, thus allowing the epoxy to penetrate the profile and create a strong mechanical bond.