Crevice corrosion occurs as a result of water or other liquid entrapment in localized areas dependent upon component/system design. These designs include primarily sharp angles, fasteners, joints, washers and gaskets. Crevice corrosion can also occur under debris build up on surfaces, sometimes referred to as “poultice corrosion.” Poultice corrosion can be quite severe, due to an increasing acidity in the crevice area.