Whether it's a pocket knife, hunting knife or kitchen knife, rust can severely hamper both the blade's appearance and its sharpness. You can prevent rust and corrosion from forming on any type of knife blade by keeping it dry at all times. Moisture allowed to remain on the metal surface will eventually lead to rust. If the knife does become wet, remove the moisture as soon as possible. If the knife does become rusted despite your best efforts, you needn't worry too much. It is possible to clean the rust from the blade.
Remove any surface rust or rust stains on the knife blade by applying some penetrating oil to the blade. Allow the oil to remain on the knife blade for roughly five to 10 minutes and then wipe the blade with a soft cloth. Any surface rust or stains should come off of the knife.
Apply metal polish to the blade of the knife. Coat the entire blade with the polish and rub with a soft, clean cloth. Continue buffing the blade with the cloth until most, if not all, of the rust and tarnish has been removed. If your knife blade has been gun-blued, do not use metal polish.
Polish the blade lightly with 0000-grade steel wool if more rust remains. Do not use circular or back-and-forth motions. Stroke the blade in one direction, from the bottom of the blade to the tip. Do both sides of the blade if necessary. If needed, apply a small amount of metal polish to the blade while using the steel wool.
Use ultra-fine, 600-grit sandpaper to remove any pitting or rough spots from the knife. Again, stroke the sandpaper along the blade in a single direction.
Buff the blade one last time with 0000-grade steel wool. Do both sides of the blade and work in one direction.
Dampen a small portion of a clean cloth with some rubbing alcohol and use it to clean the knife blade. This will remove any dust and other particles that remain on the blade.
Prevent future rust from forming on the knife by rubbing a thin coat of mineral oil onto the blade with a clean cloth.