| abstract |
An acidic aqueous coating solution for forming on an aluminum surface a coating which is corrosion resistant and to which overlying coatings adhere excellently is disclosed. The coating solution contains compounds of zirconium and fluorine. The use of boric acid in the solution is disclosed also. The coating solution is capable of forming on an aluminum surface a uniformly colorless and clear coating so that the coated surface has the appearance of the underlying metal surface, that is, the coating can be formed without changing the appearance of the metal surface. When coating a shiny bright aluminum surface, there can be produced a coated surface having a uniformly shiny bright appearance which is maintained even after the coated surface is subjected to boiling water. |