If you are planning to paint a metal chain, you will need to consider two important factors. First, because metal surfaces are not porous, paint will not adhere to them until they have been treated with a specific type of abrasion primer. In addition, because chains interlock, they painted surface will be under constant duress as the metal components rub against one another. You will need to select a durable type of paint, or the finish will quickly wear away.
Lay the chain on a concrete surface outdoors.
Clean the metal chain with a pressure washer. Allow the chain to dry out completely.
Lay the chain on top of a heavy-duty fabric drop cloth or a piece of cardboard. Apply a very thin coat of etching primer to the chain. Work meticulously to ensure that all of the metal is covered. Move the chain to expose all the surfaces.
Allow the etching primer to dry for 1 hour, and then flip the chain over and apply primer to the other side. Allow the etching primer to cure for 4 hours.
Apply two coats of metal spray paint to the chain in the same manner as you did the primer. Allow 2 hours of dry time between coats.