Abstract
For many years a traditional approach to provide corrosion protection for exterior steel applications has been the application of two coats of epoxy followed by a high performance two-part aliphatic polyurethane. The latter is used because epoxies do not have good color and gloss retentive properties. Other limitations of this traditional approach arise from the coating’s dew point and relative humidity restrictions as well as occasional concerns due to free isocyanates in the polyurethane finish.
This paper describes a new two or three coat epoxy coating system specifically developed to overcome all these limitations without compromising corrosion protection or aesthetics. The areas of use for this new technology are offshore and marine environments, pulp and paper mills, food processing plants, and other wet or dry environments. It consists of an ultra-high solids epoxy primer that optimizes adhesion even on damp metal substrates or wet coatings; a mid coat epoxy for optional film-build depending upon the severity of the service environment; and a unique high color and gloss retentive UV stable epoxy with the aesthetic properties of a good quality aliphatic polyurethane finish.
