Abstract: A conversion coating applicator includes a first liner, a hydrogel attached to the first liner, and a second liner removably attached to the hydrogel. The hydrogel includes a trivalent chromium conversion coating solution including a trivalent chromium compound, a zirconate compound, and a dye compound. The conversion coating solution is an aqueous solution.

Abstract: A conversion coating applicator includes a first liner, a hydrogel attached to the first liner, and a second liner removably attached to the hydrogel. The hydrogel includes a trivalent chromium conversion coating solution including a trivalent chromium compound, a zirconate compound, and a dye compound. The conversion coating solution is an aqueous solution.

Abstract: A conversion coating applicator includes a first liner, a hydrogel attached to the first liner, and a second liner removably attached to the hydrogel. The hydrogel includes a trivalent chromium conversion coating solution including a trivalent chromium compound, a zirconate compound, and a dye compound. The conversion coating solution is an aqueous solution.

Abstract: A conversion coating applicator includes a first liner, a hydrogel attached to the first liner, and a second liner removably attached to the hydrogel. The hydrogel includes a trivalent chromium conversion coating solution including a trivalent chromium compound, a zirconate compound, and a dye compound. The conversion coating solution is an aqueous solution.

Abstract: An aqueous conversion coating solution comprises a trivalent chromium compound, a zirconate compound, and a dye compound. The trivalent chromium compound can comprise trivalent chromium compounds such as trivalent chromium sulfate. The dye compound can comprise an azo dye, a chromium complex dye, an anthraquinoid dye, and/or a methine dye. The zirconate compound can comprise alkali metal hexafluorozirconate compounds. The conversion coating solution can comprise a phosphorous compound such as an organic amino-phosphonic acid compound. The conversion coating solution can be formed by mixing a dye additive containing the dye with a trivalent chromium conversion coating solution that does not contain a dye. The conversion coating solution can be used to treat metal substrates comprising aluminum, magnesium, and/or zinc.

Abstract: A conversion coating applicator includes a first liner, a hydrogel attached to the first liner, and a second liner removably attached to the hydrogel. The hydrogel includes a trivalent chromium conversion coating solution including a trivalent chromium compound, a zirconate compound, and a dye compound. The conversion coating solution is an aqueous solution.

Abstract: A method for electropolishing a metal substrate comprises submerging at least part of the metal substrate in an electrolyte solution and applying electrical current to the metal substrate to form an electrical circuit where the metal substrate is the anode. The electrolyte solution comprises phosphoric acid and at least one acrylic monomer and/or acrylic polymer.

Abstract: An aqueous conversion coating solution comprises a trivalent chromium compound, a zirconate compound, and a dye compound. The trivalent chromium compound can comprise trivalent chromium compounds such as trivalent chromium sulfate. The dye compound can comprise an azo dye, a chromium complex dye, an anthraquinoid dye, and/or a methine dye. The zirconate compound can comprise alkali metal hexafluorozirconate compounds. The conversion coating solution can comprise a phosphorous compound such as an organic amino-phosphonic acid compound. The conversion coating solution can be formed by mixing a dye additive containing the dye with a trivalent chromium conversion coating solution that does not contain a dye. The conversion coating solution can be used to treat metal substrates comprising aluminum, magnesium, and/or zinc.

Abstract: A stable trivalent chromium coating solution can be prepared by heating the chromium coating solution and adjusting the pH of the chromium coating solution. The coating solution can be heated to at least 35° C. for no more than 24 hours. While the solution is hot, a basic or acidic material can be added to increase or reduce the pH to a target value, respectively. In some embodiments, the chromium coating solution can have a pH of 3.5 to 4.0 and the pH can vary no more than ±0.15 while in storage for at least 20 days. The trivalent chromium coating solution can include a fluoride compound, a zirconate compound, a corrosion inhibitor compound, a chelating agent, a phosphorous compound, and/or other compounds.

Abstract: A method for electropolishing a metal substrate comprises submerging at least part of the metal substrate in an electrolyte solution and applying electrical current to the metal substrate to form an electrical circuit where the metal substrate is the anode. The electrolyte solution comprises phosphoric acid and at least one acrylic monomer and/or acrylic polymer.