Iron soup kettle with rust I have an iron kettle that is pitted with rust in pits. How do I get rid of rust so I can cook chowder in it? We have tried using a wire brush, filled with water and boiled it. Saw vinegar can be used but don't know how long to leave it in kettle or if needs to be diluted.
I'm assuming that you're referring to a cast-iron kettle. One of the common strategies for removing rust from cast-iron is to rub the oxidized areas with steel wool. You'll want to remove as much of the rust as possible that way, and then you can consider using a wire or plastic brush, soap and water.

Subsequently, once you're confident you've removed the rust, brushing with food-grade flaxseed oil (or shortening, in a pinch) and heating the pot for a period of time, then letting it cool so that the coating is mostly polymerized, will help reduce the likelihood of future rust development.

There is a guide to restoring cast-iron covering roughly the same set of steps.

The reason for preferring flaxseed oil is its polymerization properties as noted above, but you may want to see a more detailed explanation.