Method and means for treating metallic surfaces bearing protective coatings

Claim 1

A METHOD OF CONTINUOUSLY TREATING METALLIC SURFACES BEARING A CHEMICALLY FORMED COATING SELECTED FROM THE GROUP CONSISTING OF PHOSPHATE, OXALATE, SULFIDE AND OXIDE WHICH COMPRISES THE STEPS OF SUBJECTING A FIRST GROUP OF SAID SURFACES TO A FIRST MIST SPRAY OF A FIRST RINSE SOLUTION CONSISTING ESSENTIALLY OF A DILUTE AQUEOUS SOLUTION OF AT LEAST ONE ACID SELECTED FROM THE GROUP CONSISTING OF CHROMIC ACID, PHOSPHORIC ACID AND OXALIC ACID, THEREAFTER SEPARATELY SUBJECTING SAID FIRST GROUP OF SAID SURFACES TO A MIST SPRAY OF A FRESH SECOND RINSE SOLUTION ADMIXING THE DRAIN SOLUTION FROM THE SAID FIRST MIST SPRAY TREATMENT WITH SAID FIRST RINSE SOLUTION, AND SUBSEQUENTLY SUBJECTING A SECOND GROUP OF SAID SURFACES TO A FIRST MIST SPRAY OF THE ADMIXED FIRST RINSE SOLUTION AND THE DRAIN SOLUTION RESULTING FROM THE FIRST MIST SPRAY TREATMENT, AND THEREAFTER SEPARATELY SUBJECTING SAID SECOND GROUP OF SAID SURFACES TO A SECOND MIST SPRAY OF A FRESH SECOND RINSE SOLUTION, AND COLLECTING AND DISCARDING THE DRAIN SOLUTION RESULTING FROM SAID SECOND MIST SPRAY TREATMENT, AND SECOND RINSE SOLUTION BEING SELECTED FROM THE GROUP CONSISTING OF DEIONIZED WATER AND A DILUTE SOLUTION IN DEIONIZED WATER OF AT LEAST ONE ACID SELECTED FROM THE GROUP CONSISTING OF CHROMIC ACID, PHOSPHORIC ACID AND OXALIC ACID.