query: Do you wash cast iron with soap and water?
passage: Seasoning (cookware)
As with other cast iron vessels, a seasoned pan or dutch oven should not regularly be used to cook foods containing tomatoes, vinegar or other acidic ingredients, as these foods will eventually remove the protective layer created during the seasoning process. Cast iron ovens are best suited to cook food high in oil or fat, such as chicken, bacon, or sausage, or used for deep frying. Subsequent cleanings are usually accomplished without the use of soap. Detergent soaps and dishwashers can remove the seasoning on cast iron, so some cookbook authors recommend only wiping the pans clean after each use, or using other cleaning methods such as a salt scrub or boiling water.[14] The protective layer itself is polymeric and not very susceptible to soaps, and many users do briefly use detergents and soaps. However, cast iron is very prone to rust, and the protective layer may have pinholes, so soaking for long periods is contraindicated as the layer may start to flake off.
passage: Painterwork
Iron and steel work should receive a coat of oxide paint at the manufacturer's works; additional coats are added after erection. All rust should be previously removed by means of wire brushes and paraffin or turpentine. The best paints for external ironwork are composed of oxide of iron and red lead, mixed with linseed oil. The following is an extract from the building by-laws of the municipality of Johannesburg: All structural metal work shall be thoroughly cleaned from scale and rust before painting.