Cast iron wood stoves provide amazing warmth and cooking power for a home. They are often beautiful additions to a living space or kitchen area. Cast iron is extremely durable, and if properly cared for, they will last many years. Cleaning a cast iron wood stove is fairly simple and does not require any special cleaners. Simple household materials have been used for hundreds of years to keep cast iron wood stoves clean and polished. Most water stains are created by calcium deposits in hard water and can be scrubbed off safely.
Confirm that your wood stove is cleaned out and completely cool before working on it. You may want to wait until spring or summer to clean the surface. Remove stove accessories like mitten racks or cooking pieces before beginning.
Wipe down the surface of the stove completely before working on any stains. Extraneous ash, dirt or wood particles could scratch the surface while you are working on it.
Use a wire brush to remove any protruding calcium deposits (from the water stain) on your stove. You can also use the brushes to scrape any other dirt or "baked-on" debris while you're working.
Rub the stain with metal sandpaper to get the stain that is in the grooves or grain of the cast iron. Wipe any debris off the stove.
Add 1/2 cup of white vinegar to 1 qt. of warm water and pour into a bowl. Dip a scrub pad (it can be a metal or nylon pad) into the vinegar and water solution and scrub the water stain with it. If it comes up slowly, use straight vinegar. Use a toothbrush dipped in vinegar to get in the grain of the stove if necessary.
Rub the cleaned spot (or the whole stove if you cleaned all of it) with olive oil or lard to shine and protect it. The next time you fire up the stove this polishing will help protect the stove, much like seasoning a cast iron pan.
If the damage to your wood stove is severe, you may want to investigate getting the stain sandblasted. You will need to consult a professional to do this.