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.

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.

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.

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.

Biodegradable magnesium alloy implantable medical devices are protected to delay onset of corrosion, and thus biodegradability, or to corrode more uniformly. The protection allows for extended effective use of the devices while maintaining biodegradability. Examples of protective coatings include conversion coatings that at least partially remove exposed second phases from a surface of the magnesium alloy and coatings that provide a barrier between water and the surface of the magnesium alloy.

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.

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.

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.

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.