Our portable stove, the Fältovn, is thermally blackened in a salt bath. The resulting black oxide layer protects the Fältovn against corrosion. It is advisable to store the Fältovn dry after use.
The Fältovn is made for outdoor life. And outdoors, it can rain. So, the stove can get wet and start to rust.
No problem—just make sure to regularly oil the Fältovn with linseed oil. Even if the stove has already started to rust, this will still protect the metal.