Causing a crack can start with a glass jar dropped into the sink. Or it could begin with an accidental blow with a hard object. Another cause could be thermal stress if scalding hot water is poured into a cold sink, or if you overtightened the sink drain. A crack might be invisible at first, but the stresses of hot and cold water can enlarge the crack, while a buildup of dirt in the crack can darken it to the point where it becomes visible.

There is no permanent repair for cracked porcelain sinks, but there are temporary fixes. A cracked sink is purely a cosmetic problem unless the sink actually leaks through the cracks. to fix a crack in a porcelain sink

Hi

Did you find the cause and solution to your problem. I am having exactly same problem with my porcelain bathroom sink. Unable to find much help on interne.

Regards,

Sps

My only suggestion is to try, as a last resort, BarKeeps’ Friend. It works on white Porcelain kitchen sinks when they get black marks. Good luck!

The same has happened in the sink my husband uses. The sink is nine years old and first noticed this year. Mine side of the sink is fine but he does use hot water on the cold sink daily to wet shave and I think this is why only his sink has the hairline cracks. To temporarily hid the cracks I pour near bleach on them and let it sit on cosmetic pads for a few hours or overnight and they do disappear for a couple of months.

I had the same problem. Plumbing hardware store said it’s called ? craving and happens sometimes on both cheap and expensive quality basins. Didn’t give me an explanation but apparently it’s common. Your warranty may cover it so that’s worth considering

Crazing is a glaze defect of glazed pottery. Characterised as a spider web pattern of cracks penetrating the glaze, it is caused by tensile stresses greater than the glaze is able to withstand

My guess is the crazing has to do with over-tightened drain when originally installed. Plumbers don't want to get called back for leaks, so they use possibly too much torque when they tighten down the drains.

https://www.finehomebuilding.com/forum/hairline-porcelain-cracks

No its in the firing of the product I'm a potter Glaze crazing or glaze crackle is a network of lines or cracks in the fired glazed surface. It happens when a glaze is under tension. A craze pattern can develop immediately after removal from the kiln or years later.

Thanks Tammy.

Is there a way to fix this or to stop it from getting worse ?

"Is there a way to fix this or to stop it from getting worse ?"

No. It is the nature of the beast. These sinks are inexpensive and subject to thermal shock and cracking,

I had my main bathroom done I 2019 ~ before it was a year old the one sink

( under mount) got a crack right under the faucet. Now let me tell you I’m the only one that used this bathroom ~ I’m 73 at 130lbs. I don’t drop items in the sink unless it’s my tooth brush. I was told several reasons by the company that I Installed it that had to something I dropped ( really- under the faucet. ) then it was my contractors fault installLing the fixtures ( he didn’t they did). Finally they came out to take a look ~ he made the comment it’s not what he thought but didn’t tell me. But they can replace it at a discount of $150 ( the installer I had is no longer with them) . Now about two months later the other sink had a crack but at the overflow! I’m beside myself ~ to me it was lousy workmanship! Now I have to go face them again! This is a very Reputable company ~ but wont take responsibility!!!!’

It is the nature of the beast, but I repeat myself. These bad boy's are never gonna change no matter how much you love them. Kick 'em out permanently please.

I have noticed the same in my sink. I believe it’s porcelain from Restoration Hardware. Will it get worse or is this just how it will be from now on? It dost bother me but I’ve really noticed the cracks discolouring

The cracks are filling with contamination.