calcium or other sulfonate gel in an oil carrier , optionally mixed with a small amount of sodium sulfonate and tall oil fatty acids , can be neutralized with amine , e . g . dmea , to form a soap which can be dispersed in water . adding an acrylic emulsion results in an acrylic coating rich in corrosion - retarding alkali metal or alkaline earth metla sulfonates . this finish on metallurgically roughened , e . g . nitrocarburized , metal forms a firm film which can resist greater than 500 hours astm b117 salt spray .