Kitchen Sink Baskets are leaky - again

[Pseudonym]

I hope someone can shed some light here for me... and help me find a solution?

Two kitchen-type stainless steel sinks (a Kohler double-basin in the kitchen and an Elkay single basin in the laundry room), both originally installed by a plumber during remodel of those rooms.

After about three years, I noticed the putty under the edge of all three strainer flanges had disappeared from view. It used to be visible as a white ring all around and under the edge of the flange.

I replace the laundry room strainer with a new one, and it hasn't leaked (it's been a year) - BUT there is no visible putty under the flange anymore.

Today I found the non-disposal side of the kitchen sink is leaking. The putty is no longer visible under the edge of that flange, either.

I've never seen this happen in any of the homes I've lived in. What could cause the putty to wash out or dissolve? Should I try again with putty? Should I give 100% silicone a try? Should I try to find strainers that use a gasket under the flange instead of putty or sealant?

Thank you for any help!

 

[Dj2]

"What could cause the putty to wash out or dissolve? Should I try again with putty? Should I give 100% silicone a try? Should I try to find strainers that use a gasket under the flange instead of putty or sealant?"

Is the strainer loose? Not fully tight? If yes, tighten it.

If no: Remove the strainer and check the condition of the putty. If the putty is cracked, dry or missing then you have to redo it: either new putty or a thin gasket. You may want to try gasket this time around (Sioux Chief, less than a buck).

I have never had plumber's putty disappear on me if the strainer was snug and tight.

 

[Sponsor]

 

[LLigetfa]

I fail to see a need for putty on a steel sink. The rubber gasket should seal on its own. Sometimes a tiny bit of putty on the threads may be all that's needed.

 

[Pseudonym]

Thank you for your help dj2. The strainer wasn't loose, but the putty did wash away from under the flange.

I did a test fit after cleaning everything up. I can't see anything obviously wrong with the strainer basket, and I can't see anything obvious about the sink lip. However, the flange doesn't sit fully flush and in full contact at the edges. The rim of the flange is up off the sink lip enough to slide the tip of a plastic butter knife under there.

 

[Pseudonym]

Thanks LLigetfa. To be clear, you're saying I shouldn't need to putty under the flange at all? Just assemble the strainer with the flange directly in contact with the sink, and the rubber ring on the strainer under the sink bottom should take care of the seal?

 

[LLigetfa]

...and the rubber ring on the strainer under the sink bottom should take care of the seal?

Correct. A small bit of putty on the threads won't hurt.

 

[Reach4]

If a ring of putty was visible for 3 years, I would wonder if maybe the nut under the gasket was not tight. A special wrench can help with that.

shows one example.

 

[LLigetfa]

I would wet the rubber gasket with a little soapy water so it doesn't resist and try to bunch up while tightening. I only use putty under the flange on non metal sinks which have an uneven surface mostly just to keep the gunk from collecting there. The seal really is only needed on the underside except where there is an integrated overflow.

 

[Pseudonym]

Thank you all for your help.

I have the special nut wrench and confirm the nuts seemed very tight to me on both strainers, including my replacement job. I'm not experienced, though, so it's possible I'm wrong!

I will give a try installing the strainer without putty, and will soap the gasket a little to ensure it doesn't bunch, that's good idea. I bought new gasket sets so don't need to reuse those parts.

My only experience is as a homeowner who has never had a sink basket leak under the flange on any sink I've thever had. I'm sure all used putty based on the look around the flange. These have all been enameled or porcelain, though, the two sinks I have now are the first stainless steel sinks I've ever had.

It will be this weekend when I give the replacement another try, so won't post back until then.

Thank you all again for your assistance.

 

[Terry]

With a Stainless Steel sink, I can't use very much putty, as it makes it's way out over time and loosens. It's a judgement call on how much to use.
If it's a deeper thickness cast iron sink, those take more putty.
No putty on the threads for a sink basket. I do use putty on drains for lavs, but that's a totally different animal.

 

[hj]

I ALWAYS remove the "bead" of putty, when i install a drain or disposer. IF there is putty visible, then the drain was not tightened properly, probably because the installer got putty in the threads. A rubber gasket "under the sink" will do NOTHING to prevent the drain from leaking, and NO PUTTY on the threads. You need some putty between the drain and the sink, and after it is tightened you should NOT see ANY "line of putty" around the drain. REgardless of how much putty you use on the drain, when it is tightened properly ALL EXCESS will be squeezed out.

 

[Pseudonym]

Thank you Terry and HJ.

So now I think I have: 1 vote for using a gasket under the flange (no putty method), 1 vote for nothing under the flange and let the rubber ring underneath the sink make the seal; 1 vote for minimal putty, and now 1 vote for the rubber ring will not make the seal.

Not sure what will work but I guess I can try. It doesn't cost me anything except maybe a leak to try the sink strainer without anything 'topside' and see if the rubber ring underneath will make the seal. If that doesn't work, it costs me a buck or two to try the 'topside' rubber gasket. If that doesn't work, then I'm down to putty or silicone...?

 

[Terry]

A rubber gasket under the sink does nothing. Both hj and I agree on that. Between the two of us, you're looking at 110 years of experience.
Under the flange, you can use putty, which works just fine, or Silicone. They also make a gasket that will work under the flange. Frankly, hj and I just use a little bit of putty and it's been working fine.

 

[hj]

A gasket UNDER the flange would have to be VERY thin, otherwise it will raise the drain above the sink and all the water will NOT drain out.

 

[Pseudonym]

Thank you for the additional info.

 

[Pseudonym]

So it has been five years, here's an update.

I replaced the putty once again, a couple of years after making this post. I used very little and tightened down hard. Still the putty got soft and liquid-y and eventually washed out from under the strainer.

I do now believe I was mistaken and the bottom of the sink is defective. With an inspection mirror I saw a small ripple and dent in the rim upon which the strainer rests. When I replaced the putty I bought a new strainer and observed same imperfect fit.

A year ago I cleaned everything up once again and this time used the Sioux Chief gasket mentioned by Dj2 in place of any putty. One gasket was not enough and no matter how tight, it leaked. So I used two gaskets and tightened down hard, no leak. Ran hottest water for 15 minutes, was able to tighten down a bit more, still no leak. It has been leak free ever since. Time will tell if this solution lasts. Thanks again to all who responded.