: I am remodeling a bathroom in an antique style and using an old iron clawfoot tub. The tub is in very good condition except for some rusty build-up around where the old metal overflow drain cover was located. I would like to know the best way to remove such buildup from the porcelain surface. Also, what is the best way to keep the interior of the tub looking good after regular use. We live in the country and our water does have some iron in it. Thanks!remember any thing you do will degrade the glaze on the porcelian finnish so be careful. you can of course scrub it with scouring powder. you can try a light acid such as lemon juice or stronger such as muriatic. once cleaned polish with auto or boat wax, be careful and dont get any on bottom of tub, just the walls of tub. since you know you have iron in the water supply, consider a water treatment unit to remove iron from supply.