My porcelain kitchen sink somehow got a slight depression in it, causing water to pool in a roughly 7" x 7" area. I'm considering replacing the sink to solve this, but I'm hoping there's instead a cheap, quick hack I can do on the current sink. I don't really care about aesthetics, and I use a sink grid in case that makes a difference. I was thinking I could fill in the depression with some kind of waterproof substance that can adhere to porcelain.
Using a level app, I confirmed that the sink is itself perfectly level. The depression rises upwards towards the drain at an angle of about 0.5°, while the non-indented side slopes downwards towards the drain at an angle of 1°.
Here are pictures showing the water pooling. In the second picture you can actually see a dark part of the reflection curving upwards from the bottom, cutting across the lighter reflection to its right. That's the edge of the depression.