hairline crack in new sink

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Heyworth, Nov 5, 2004.

  1. Heyworth

    Heyworth New Member

    Messages:
    1
    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?
  2. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    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.
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,247
    Location:
    Cave Creek, Arizona
    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.
  4. kordts

    kordts In the Trades

    Messages:
    551
    Location:
    exurban Chicago
    Who is this links clown? They posted the same thing in about 10 different threads.
  5. A struggling company with broken links...
  6. 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
  7. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,247
    Location:
    Cave Creek, Arizona
    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.
  8. 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
  9. Randyj

    Randyj Master Plumber

    Messages:
    1,047
    Location:
    Alabama
    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.
  10. Pewterpower

    Pewterpower New Member

    Messages:
    262
    Location:
    Tampa
    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.
  11. Randyj

    Randyj Master Plumber

    Messages:
    1,047
    Location:
    Alabama
    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.....
  12. Cal

    Cal New Member

    Messages:
    228
    Location:
    Northern Virginia
    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
  13. Randyj

    Randyj Master Plumber

    Messages:
    1,047
    Location:
    Alabama
    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.
  14. markts30

    markts30 Commercial Plumber

    Messages:
    630
    Location:
    Phoenix, AZ
    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...
  15. Randyj

    Randyj Master Plumber

    Messages:
    1,047
    Location:
    Alabama
    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.
  16. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,313
    Location:
    New England
    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.
  17. Randyj

    Randyj Master Plumber

    Messages:
    1,047
    Location:
    Alabama
    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.....
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