If you’re considering installing wood doors on your metal shed, there’s no need to worry about rust. Metal shed doors are often made of steel, which is highly resistant to rusting.  In any case, if you live in an area with high humidity or salt air, you may want to consider using a rust-resistant primer on the double door frames before installing the doors. This will help to protect the metal from corrosion and ensure that your doors last as long as possible.