I am working on a project where I need to blacken some steel components to a matched finish, including a length of steel chain. I am using Jax Iron, Steel and Nickle Blackener: https://jaxchemical.com/shop/jax-iron-steel-nickel-blackener/
Usually with this product I follow up with a Rustoleum spray on enamel coat to prevent rust immediately after drying from the blackening process. This has always worked well for me. However I am wondering if this is feasible for chain, since the proximity of the links will prevent the enamel from reaching all surfaces, and the friction between the links when moving seems like it would take the enamel off.
How should I go about rust proofing the length of chain?