I wasn’t aware they made undermount sinks that old. I’m a bit of a cast iron fanatic. May we see a couple of pictures? Cast iron sinks don’t just “go bad” but they can chip and rust, both of which are usually obvious. You will know more once the sink is removed, but for now, look up underneath with a flashlight and see if you see anything that concerns you. It is possibly a better sink than you could get from Kohler today.

In my sink replacement business, I replace cast iron sinks regularly. They wear out:

I had no idea a sink could be re-enameled...will def check on that!:) I actually really like the sink as is + hope it doesn't crack when my contractor removes it to demo the kitchen!! Thanks everyone for the tips!

I'll be interested to hear what you discover about re-enameling. The last time I looked in to it , maybe 7 or 8 years ago, there was only one place in the country that did actual re-enamel work.

I haven't had one in a kitchen since I was a kid, but there is a gorgeous (to me) cast iron undermount that is 14" deep in my laundry and one identical to it in the hobby shop downstairs. Both original to the 1955 house. Flawless. I wouldn't give them up for anything! But one in a new kitchen I was sinking $$$$ into? I'm not sure, I'd have to see it.

"I had no idea a sink could be re-enameled...will def check on that!:)"

They can't be, at least cost effectively:

I have never seen re-enameling work, but I’ve only seen it done with old bathtubs. The ones I’ve seen look worse than ever two years on. Now, I say that. The process was described as re-enameling. But what I have seen may have been more like a paint or epoxy type finish.

The harsh cleaners like ajax or comet are what ruins the enamel finish, but I believe that is what most people used to clean sinks beginning in mid 20th century.

MizLizzie-

There is a true re-enameling process, not tub refinishing. But, as I said above, last I looked into it there was only one place in the entire country that did it. Maybe in Kentucky or Tennessee....It was expensive, and you had to figure out how to get a heavy cast iron sink there and back.

I had one in my last kitchen for 15 years and it still looked new when we renovated so we installed another one. Going on 6 years with this one and no regrets! Both were Kohler cast iron in white.

http://www.customceramic.com/index.htm

is the one place in the US that could re-porcelain a sink. I've read elsewhere that this place is no longer doing that but posted the link anyway. Because I might have read bad info or remembered wrong.

More info here: https://retrorenovation.com/2011/09/06/real-porcelain-enamel-coating-to-restore-your-drainboard-sink-tub-or-stove/

Update May 2015: Custom Ceramic’s waiting list is now two to three years long. Yes: Years.

From the comments section: I was wondering if anyone has had any luck hearing back from Custom Ceramic Coatings? I have been trying since last year. I’ve tried sending emails and calling and leaving messages and have not heard back.