Remove rust from chainmail
Should your chainmail get some surface rust, it’s important to remove the rust. Mail rings are thin, so if you leave the rust on, they will break and will need replacing.
There are two ways to remove rust from Chainmail.
You can quite easily remove the rust from chainmail by using a rust removal product, which you can buy at a hardware store.
Just soak the chainmail for a while, rinse the rust removal product off with water and let the chainmail dry.
After it’s dry, treat the chainmail with oil to prevent it from rusting again.
Mechanical cleaning uses abrasion to remove the rust. If there’s only a very small amount of rust, you can simply rub the chainmail on itself, or wear it for an extended period.
If there’s too much rust on your chainmail for that to work, you can “tumble” the chainmail. A rotary tumbler would be the best option, as vibratory tumblers often can’t handle the size and weight of a larger chain item, such as a hauberk.
You could use a cement mixer drum, but you would need to remove the baffles that are inside the drum first.
To tumble your chainmail, you need to put a tumbling medium (walnut shell, bran, steel shot etc.) in the drum along with the chainmail. This tumbling medium is what’s responsible for abrading the mail. Fun fact: in medieval times one would put their chainmail in a barrel, and roll it down from a hill to remove the rust.
When the rust is removed, you need to re-oil the chainmail before storing it, to prevent it from rusting again immediately.