Small Round Dips in Bottom of Cast Iron Bathtub

We just purchased a house 6 months ago, and during the inspection, there was no water damage in the crawl space or any mention of water damage in the bathroom, but we've noticed small round dips on the bottom of our cast iron bathtub. The bathtub is not a clawfoot tub so we can't see what's underneath it, but at least during the inspection, there was no subfloor damage. Is this something to be concerned about?
We are considering sprucing up the bathroom (i.e. reglazing bathtub/tile and new sink/fixtures), but would like to avoid doing a full bathroom remodel as this is our only bathroom in the house and we just can't afford it financially. But we'd hate to "spruce" up the bathroom and find out we have to completely remove the bathtub.
  3 answers
  • Not so sure what you mean my dips? A cast iron tub regardless if footed or simply set into place is solid and should not be anything other than smooth on the surface. If the tub is older and has been resurfaced (painted) it is possible that these dips are the surface of the paint failing or orange peeling? Can you post a photo? Or perhaps explain a bit more what you mean about dips?
    • Needhelpwithhouse Needhelpwithhouse on Jan 30, 2014
      @Woodbridge Environmental Tiptophouse.com When you step inside the bathtub, you can feel dips or spots that seem lower than the rest of the tub. You can't see anything when just looking at the bathtub, but you can definitely feel it with your feet. When you run your foot across the bottom of the tub, there's about 2-3 round spots where it is slightly lower than the rest of the tub and the middle portion is about 1/4 inch lower than the rest of the tub. I'm not sure if that helps to explain it more.
  • This sounds as though the tub was already refinished. Cast iron tubs when they become chipped rust in those areas. In some cases they peel off almost layer like metal flakes that may have resulted in these dips your speaking about. When they refinish they will grind the surfaces smooth so when they refinish the surface it goes on smooth. If this is indeed the case, nothing to worry about, but you may not be able to refinish the tub with great success. Something to consider. IN any case, the cast iron does not bend it simply cracks. So no worry about its integrity.
  • Jennie Lee Jennie Lee on Jun 18, 2016
    How big are the dips, and how many are there, and where?