Copper, Zinc, and Aluminum Plate Corrosion Liquid: For the aluminum version we use 1.5 times more water in summer and warm water in the winter, and dilute the solution for the copper plate and about 0.5 times more water for the zinc plate. Corrosion fluid (ferrous chloride liquid) is a highly acidic liquid used for corrosive recessed techniques such as etching and aqua-tint, and can be used for corrosion processing copper, zinc plates, aluminum plates, and etched plates. The corroded plate is dipped in a solution of neutralizer, then neutralize it before washing it with water.