DS - Painting in Our Bathtub

Oh, how DS misses our bathtub at home! DS loves playing with water in the bathtub and when he was old enough, we have been letting him do painting in the bathtub - finger painting on the sides of the bathtub or on paper, or using a brush. Unfortunately, when we were in Taiwan, the apartment that we rented had a bathtub with a rusted bit on the floor of it. It seemed like the previous tenant had dropped the heavy shower head onto the floor of the bathtub and chipped off the paint as a result. Over time, the chipped part probably started rusting away. Because of this rusted bit, we didn't allow DS to play in the bathtub, so he was missing all his water toys and painting (which I don't allow him to do elsewhere because I dread to think of the mess that will be created!).