Paint stripper, gloves, and a brush. Check with paint stores for stripper, and for the RIGHT gloves.
You can paint about anything. Depending on the temperature the iron is getting will say what type of paint you need. (there is special paint for engines) if the iron is going to get extremely hot, you might not find a sutable paint.
A cast iron tub is about 325lbs. steel is about 75lbs. Tap on tub if it sounds solid it is cast iron.
You don't, you remove the plastic junk and replace the toxic plasatic with cast iron
Polished epoxy
Scrub it with Goof Off.
You can remove mineral deposits from your teapot with a mild vinegar solution.
when we apply paint on iron articles moist air cannot attack iron and prevent rusting
A good way is to head over to chowhound.com. They have a lot of questions and answers on how to remove oil residue from a cast iron skillet. An example is to boil some water and leave it in your skillet then wash off.
Physical, no chemical reaction is occuring, your just covering the Iron with paint, the paint doesn't react with the iron.
Paint thinner will remove it.
You don't remove it. You have to paint over it.
I always use a paste type paint stripper. My favorite is 'Circa 1850' -If you use this BE CAREFUL, it's a very corrosive solvent. Use gloves, and dispose of the waste properly.