New Day Tornado Shelters Logo

New Day Tornado Shelters Logo

Rusting is no problem.

Yes.  And so could The Iron Bridge in Shropshire, England.  But I think the reason it is still standing since 1781 is because of a trait of Ferrous metals.  Unlike alloys of aluminum or magnesium, corrosion developing on iron-based metals creates its own barrier against deeper corrosion.  In other words, in heavy gauges of steel, rust inhibits more rust.