Hairline crack in new sink

Heyworth · Nov 5, 2004

I just installed a new Kohler cast iron/porcelain kitchen sink and have discovered a hairline crack in the porcelain about 2 inches long running out from under the drain collar. How bad is this? To be specific, is it so bad that I should replace it, as this would entail pulling and then reinstalling all the plumbing as well at the countertop? (It's an undermount sink, of course). The Kohler warranty would only cover the sink itself and none of the labor, so swapping it out would cost me a bunch. And I need to decide soon, since putting up the backsplash is the next project, and that will further complicate the process by making it harder to pull out the countertop.

Right now, the crack isn't getting worse, and it isn't that unsightly. I can live with it, but if it's going to get worse, or if it's going to cause the sink to rust out in the next, say, 10-15 years, I'd probably want to replace it. Also, is there some compromise solution--some way to seal the crack so that it won't seep and cause damage to the cast iron below?

Jimbo · Nov 5, 2004

If the defect is just in the porcelain, i.e. more of a scratch than a crack, it may not get worse. If it exposes metal, there is the possibility for rust. I would ask your supplier if they have any experience with touch-up. You could also ask Kohler for advice. It sounds like you are amenable to something which may not be 100% perfect visually as long as it will last. This is a very reasonable position and hopefully Kohler will work with you.

Sponsor · 2022-01-29T12:20:58-0800

hj · Nov 5, 2004

scratch

I would have the supplier check with Kohler. As stated, if it extended to the cast iron base metal, even if it is just where it starts corrosion will occur and "pop" the porcelain some time in the future.

Kordts · Jan 5, 2007

Who is this links clown? They posted the same thing in about 10 different threads.

Dunbar Plumbing · Jan 5, 2007

kordts said:
Who is this links clown? They posted the same thing in about 10 different threads.

A struggling company with broken links...

Geniescience · Jan 6, 2007

yes, replace it

heyworth,

this problem can't "stay the same". Maybe within months of using it, or if not, then it'll take years. But that was your question, which i hope to answer. Far better now to put in a new sink, while everything is do-able for far less hassle, than later after you hace been hating it for a long time.

post a picture of the crack. How can (you or anyone) be sure than nothing will worsen? The enamel might grab moisture under its surface (like old dinner plates from our grandparents' generation), which will make the crack very visible, or the metal might rust enough to seep and show through the crack, and the crack might lengthen...

I don't see how a new sink will involved "redoing all the plumbing" - actually you said "... reinstalling all the plumbing ... ". I don't see how it involves any hard work at the countertop either.

These are my reactions, my feelings, my assessment, my answers. If i were on site i might answer differently.

david

hj · Jan 6, 2007

sink

Then you have never seen an undermount installation that did not, or could not, make provision for removing the sink from underneath. When that is the case, then entire countertop has to be removed, or at least the section with the sink and then reinstalled and the seams sealed again. It is not an easy job, wlhich is why my sink is routered into the top of the countertop, flush with the surface.

Geniescience · Jan 6, 2007

good to know

i'll pay more attention to how undermounts can be "stuck" in place ...

routering it into the top is smart. --- but ... that would it impossible to remove from a tiled countertop.

Cutting the drain pipe underneath is not mission impossible either. There must be somethign criticla about the supports that i have forgotten or never noticed, when i have looked at diagrams. Never done an undermount. Have often wanted to.

david

Randyj · Jan 6, 2007

I've not had to deal with but a few under mounted sinks mounted to granite tops. All had been just stuck to the bottom of the granite and appear to be relatively easy to remove once "unstuck" from the bottom of the granite. A couple of short boards and long bolts thru the basket holes makes mounting one in place very easy. As a matter of fact, the ones I recently plumbed were installed after the counter tops were put in place... so, what's the big deal? I'd rip out the plumbing back to the p-trap connections and stops then gently work the sink loose from the granite bottom..if hung with silicone like the ones I've seen. It's just another aggrivating and time consuming PITA.

Pewterpower · Jan 6, 2007

First question is: Why did your contractor (or yourself) allow a brand new sink, with a crack in it, to be installed in the first place?
That aside, I think you should replace it. You are going to regret it everytime you use the sink, and your eyes are automatically riveted to that defect.

Randyj · Jan 6, 2007

I think someone would have to pay me to keep a new sink that is defective. I wouldn't look at that crack every day for nothing.....

Cal · Jan 6, 2007

REPLACE THAT SINK NOW !!!

It is going to suck in a few months . Stains , moisture , bubbling !

ANYBODY who hasn't replaced one ,,,,, please stay out of this !

It is NOT easy ! They aren't just "glued" They are epoxied . BIG diff .

Do it now , Do it Right .

Cal

Randyj · Jan 6, 2007

Cal....must be different strokes for different folks... the ones I worked on were siliconed...as is the one in the house my daughter had built. I may not know alot...but I definitely know what silicone looks and smells like and can read the name on the tube it came in....and heard the installer when he told me "it's just siliconed in".... Heyworth probably knows what he's got.

Markts30 · Jan 6, 2007

All the undermounts I have dealt with were epoxied to the underside of the counter then the seam was siliconed...
The bonding is done with the epoxy...
One had to be removed as it moved during the curing time and was crooked - had to have the counter removed and the sink CUT off the counter - ruined the sink but saved the counter..
Not something I would like to have to go through...

Randyj · Jan 6, 2007

That's why I love this board... learn something new every day... thanks to you guys keeping hanging around... I do know that this guy who installed the counter tops has just started doing it and is "cheap"... maybe I need to clue him in on it too.

Jadnashua · Jan 6, 2007

My granite fabricator routes T-slots in the underside of the counter which provide the primary support for a sink. Slap some silicon on the flange, set it in place, tighten down the nuts on the T-bolts and bracket, and you're done. Epoxy would work, but is overkill, I think. You have to work with what you've got, though. I'm not sure if this would suffice for a CI sink...there, you would probably build a support basket, but still the connection could be silicon and the T-bolts and brackets, the basket would be backup.

Randyj · Jan 6, 2007

Jadn... apparently there are zillions of methods and like zillions of situations...no one is absolutely correct or not all are wrong. Myself, if it works, use it.....

Ellie Bee · Apr 7, 2021

I had a plumber cut the counter, lose a drawer to fit before he pointed out “scratches” (his word) in a new, drop in sink. I hesitantly said ok to what looked like scuffs considering my counter had been cut and scuffs would eventually happen.
I came into the kitchen once the installation of faucet, etc was done. I moved the faucet and saw cracks. Dark cracks. I ran my hand over them. It looked like their being wet made them darker? When I pointed out the cracks weren’t scratches but are cracks and said I was sorry I hadn’t run my hands over the “scratches” to feel them. Plumber left very upset. The job involved removing/replacing old sink & faucet, garbage disposal, shut offs and line to dishwasher—total is $1550. I feel awful because before the drop in sink was completely installed I honestly didn’t see what the plumber said were scratches—once installation was complete, they’re cracks and visible. What’s a fair resolution. The sink photo is the sink a few hours after installation.

Terry · Apr 7, 2021

I would not have installed a damaged cast iron sink. You as the plumber inspect it first.
It may have been dropped or something dropped on it. It didn't come from the factory that way.

Ellie Bee · Apr 8, 2021

Terry said:
I would not have installed a damaged cast iron sink. You as the plumber inspect it first.
It may have been dropped or something dropped on it. It didn't come from the factory that way.

I’ve read that Kohler has had issues w porcelain sinks cracking right out of the crate or after some use. I have found four more areas in the sink w hairline cracks that are beginning to darken/discolor, any may be getting bigger. It’s odd because the plumber left after installation and my pointing out that the deeper, discolored cracks were not scratches. No payment yet. I’ve called and been told they’ll get back out when they can. I haven’t really used the sink. I can’t help but think I need it replaced. It feels awful to pay $1550 for a new, but visibly cracked sink. Am bummed.

Hairline crack in new sink

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