Both the Magnalock core and strike plate are plated and sealed following a military specification. Because of this plating and the sealed nature of the magnet, the Magnalock is weatherproof and may be used outdoors. If rusting appears, the most common cause is that improper cleaning (with steel wool for instance) has occurred and this has stripped off the relatively soft plating. Once the plating has been removed, it cannot be restored in the field, so the lock will have to be periodically cleaned and coated with oil or other rust inhibitor. A rusty Magnalock will still function but at reduced holding force. If the product is installed in a heavily corrosive atmosphere, such as near the ocean, it will eventually rust even with non abrasive cleaning. The only answer then becomes continued periodic removal of the rust.