What is my sink made of?

What is my sink made of?

Trying to figure out what kind of sink I have- I know it’s not porcelain, as it doesn’t have that super-shiny type of finish that wears off in patches. It’s off-white, and instead of the porcelain finish wearing off, I have a network of spidery cracks, like alligatoring in paint, but the surface is smooth.

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The reason I need to know is, I want to refinish the sink so it will last me a few more years until I can afford a complete remodel. I know typical sink refinishing only lasts that long, and am ok with it.

How can I tell if it is acrylic, fiberglass, or something else? Thanks.

What is my sink made of?

What is my sink made of?

  • cat_ky

    Looks like a builder grade sink from the 60;s or 70’s. They were steel with some kind of thin porclain like finish on them. They did chip easily and cracked like that at the bottom. Rather than try to do anything with it, you might be better off, to go to habitat restore, or Craigs list, or other resale stores and find a cast iron one in a color that matches your kitchen. I really dislike stainless steel sinks, but…you can buy some very inexpensive ones at Lowes, or Home Depot, or find one of them at Habitat restore, or craigs list too. Someone tearing out a whole kitchen, may just give you one, since it is only temporary for you anyway.

    • PRO

      Joseph Corlett, LLC

      What is my sink made of?

      Here’s a refinished sink. Don’t waste your money or time, please. This is worse than what you have.

      Kathie Rost thanked Joseph Corlett, LLC

    • Jane

      If it’s a standard size like 22”x33” overmount, you could go on nextdoor.com and craigslist to see if anyone is trying to get rid of a sink after a remodel. I picked up a kohler cast iron sink on nextdoor.com, and I am trying to get rid of one now. (I also have an extra faucet.) If you don’t see one under “free stuff”, you can post an ISO and eventually someone will probably have one for you for free. Keep an eye on the postings.


      Cast iron sinks are hard to ditch because they are so heavy. You may need someone to help you install it. You can find people to do that on nextdoor.com too. You may not need a plumber – just someone who can help you lower it carefully into the hole after silicon caulking the edge. The sink plumbing can be DIY.


      There are lots of plumbers on nextdoor.com and I bet they remove perfectly good sinks (and faucets) all the time.

      Kathie Rost thanked Jane

    • cat_ky

      Another place you might try to find a used one is on Facebook market place for your area.

      Kathie Rost thanked cat_ky

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      Kathie Rost

      Original Author

      Had to laugh, cat_ky, the house was built in ’89, but I guess the sink looks like it’s been used since the 70’s! 🙂

    • cat_ky

      They probably didnt change them much in the 80’s from earlier. They chip easily too.

      Kathie Rost thanked cat_ky

    • pennydesign

      Kathie, look at the underside of the sink…

      Kathie Rost thanked pennydesign

    • Kathie Rost

      Original Author

      The underside looks like it’s cast iron. So I guess, porcelain?

    • pennydesign

      Yes. It’s a shame this happened…some rough use, I guess 🙂 Old old porcelain can be refinished well as it was so thick. Yours would need a new coat of something over it. Are you able to have a handyman replace it with something the same size off Craigslist or Habitat Restore? Usually Craigslist ones come complete with faucet…

    • Kathie Rost

      Original Author

      I’d love to replace it but it’s totally bonded with the counter in some wierd way, sort of as an undermount sink. I was told it could not be replaced, so I’m looking to get a few more years out of it before a major remodel (College bills are killing us right now!)

    • pennydesign

      3 years ago

      last modified: 3 years ago

      I hear you…I have a budget of nothing, too.

      I wonder if the Rustoleum tub and tile would work? Maybe more coats than recommended. I’ve never used it, but I know that (as with anything) prep is key.

      Also I would let it cure longer than it says (whatever that is) and use your bathroom sink…then you can get some sink mats to protect the finish further..

      Read the reviews and go into it knowing that you have to baby it…https://www.amazon.com/Rust-Oleum-7860519-Refinishing-2-Part-White/dp/B000PTSBKW

      Good luck and let us know the outcome!

      Kathie Rost thanked pennydesign

    • Kathie Rost thanked cat_ky

    • mama goose_gw zn6OH

      I had a bathtub refinished about 10 years ago. It’s still in good shape, even with 4 people (2 adults,2 kids) taking almost daily showers, and baths for the toddler. I’ve had to touch up a few small nicks with appliance epoxy, and we’re careful about the kind of cleanser we use on it.

      But, I would never recommend that method for a kitchen sink, with silverware, knives, pots and pans, grit from salad greens, and possible dropped items like plates or glasses.

    • PRO

      Sophie Wheeler

      That’s a $30 fix. Buy a new to you used sink. Lift that old one out. It’s just plumbers putty and some clips.

      This is a simple fix that doesn’t need any expensive kludges that will only make it worse.

    • PRO

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      Joseph Corlett, LLC

      Sophie, take another look at the picture, please. I don’t think there’s going to be any lifting the old one out; it’s apparently undermounted to tile. It might lift out if it were cut out first:

      What is my sink made of?

    • PRO

      Sophie Wheeler

      I didn’t see tile. All I saw was rust. It doesn’t appear to be a tile in edge to the sink. Of course, someone could have kludged something. Better pictures would certainly help with assessing the situation and what can and can’t be done.

    • ci_lantro

      Cut it away with an angle grinder, leaving the rim intact. (Cut away the bowls an inch or so away from the underside of the countertop.) Cut away what remains of the faucet deck.


      Don’t disturb the sink rim/ countertop sandwich.


      Plop a top mount stainless steel sink in the hole.


      Before you start, make sure the new sink will cover the hole or how you’re going to fill in the hole. May need to glue and screw in some 1x filler.

      Kathie Rost thanked ci_lantro

    • Kathie Rost

      Original Author

      Thought about doing that, ci_lantro….but no SS sink I’ve found after months of searching will fit there. I’m afraid I’m stuck with the refinishing option or live with it. Thanks.

    • Jane

      Kathie, what is your countertop material? I think we may be confusing that with the sink?

      Is the crackle the only issue? Or is there leaking or seepage?

      Can you see who the maker of the sink is by looking at the bottom with a flashlight and maybe a mirror or phone camera (so you don’t have to empty the cabinet)?

      If you can ID the manufacturer (and model/year if you can see it), you might call the manufacturer to ask what your options are and what the material is. For example, I think kohler calls their cast iron coating “enamel”. The manufacturer might tell you how to disassemble the sink from the counter, or coat it or if it’s even a problem. My new elkay (composite) over mount sink came with instructions and I even called them a couple of times.

      If it’s only crackle and cosmetic, you could think of it as art like the crackle on a lot of new glazed vases or tile.

    • PRO

    • j9swimmer

      Not an expert, but for years I lived in a house that had a sink nearly identical in shape and finish to your photo. It was an enameled sink over a heavy base. I assumed it was cast iron. But it may have been an Americast sink (similar to cast iron?).. Anyway, like your photo shows, my sink had a crackle or craquele finish in the ename on both bowls. However, the glaze was still smooth. If this is also your situation with a smooth glaze but crackle, then I predict your sink will last several years more, as this finish may have been intentional.

      Kathie Rost thanked j9swimmer

    • Kathie Rost

      Original Author

      Thanks, from all this I believe it’s enamel over cast iron, and the “crackle” finish is typical when they get old…definitely not intentional. The glaze still feels perfectly smooth, though, as you say yours was.

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