The longer you air dry, the more rusty it looks. When tin is completely dry, it will turn a copper color with uneven streaks and swirls. Use all metal cookie sheet with sides. DO NOT use teflon coated, enamelware, glass or plastic containers. Immerse tin into solution.
Tin has to be completely covered.
It will start rusting immediately in the solution. It takes approx. Lift out of solution and stand on edge to dry. It will become very rusty. Let air dry completely for approx.