Tests reported here are continuations of preliminary investigations made in 1951 by the Bureau of Ships in cooperation with International Nickel Co., Inc., and Dow Chemical Company on the effect of controlled electrical potentials on underwater paint systems.
The problem of finding suitable paints and coatings for use in combination with cathodic protection can be divided into two parts.
As a consequence of this dual-sided problem, two studies were undertaken with the following objectives:
An ideal coating for use as a dielectric shield should be a non-conductor with easy application, high degree of adhesion, resistance to alkali (cathodic reaction products), impermeability to seawater, toughness, flexibility and ability to withstand continuously impressed cathodic voltages to 6.0 volts.
This series of tests was made on sandblasted mild steel panels, coated with a system consisting of an undercoat (anti-corrosive system) and the topcoat (antifouling system). Coatings and sources are listed in Table 1...
