Hello- I recently etched an Altoids tin. I would like to leave the etched tin in an outdoor location as a memorial to something. The etching includes text, and I am worried about oxidation of the steel ruining the tin quickly. I would ideally like for this to last several years (as long as possible) What is the best way to protect the item from rusting? Should I just use a rust-proof varnish coating? If so, what is the most effective and long-lasting type/brand? Would a better option be to attempt cathodic protection? I could easily roll up a lot of Magnesium ribbon and place it within the tin- how long will this last? This is going to be left on a rooftop in Florida, so it will be exposed to humidity, sun, and rain, but it will not be submerged. Does this make cathodic protection ineffective? Thank you.