Mystery leak from stainless steel kitchen sink

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Zanne

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I have a double basin stainless steel sink that was installed in the late 1980s. The left basin has a garbage disposal. Right basin has a standard drain. I was standing near the sink after washing some things in the sink (water going to both basins) when I heard a dripping sound. I looked under and reached to touch supply lines to feel for water when water dripped on my arm from the bottom of the right basin. I felt around the drain and it was dry, but water was dripping from a spot a couple inches in front of it. I felt the underside of the sink and then looked-- there is a rectangular black patch that feels like rubber. Water is leaking from the edge of it. I looked in the sink and saw no damage on the top side. It doesn't appear to be close enough to the drain for the water to be coming out of the drain.

WTH could this possibly be?

I'll try to get pictures later (after I wash more dishes and get things cleared out of the way). I drained the water out of the basin so it is no longer dripping, but it's confusing the hell out of me on how it could be leaking from a patch when there is no visible damage from inside the sink basin.

Any ideas?
 
Remove the black pad if it’s saturated. It’s there as a sound deadening pad to absorb noise snd vibration.

Aftrr you do that, turn the light off in the room so it’s dark. Place a flashlight under the sink in the cabinet.

inspect inside the sink for pinholes of light indicating a hole in the sink.
 
Thanks, Twowaxhack. It makes sense that it's there to deaden sound. Will have to go grab my flashlight and take a look for pinholes.

Edit: Well fuuuuuuuuuuuu....
Two little pinholes right next to each other that were covered by that pad. Pad won't go back on.

I wonder if I can temporarily patch it with flex seal. Assuming I probably need to replace the sink. I was trying to explain to Mom what was wrong and she thought I was saying the pad had a hole and I had to say: "No, the sink has holes".

So, thank you for the info that helped me solve the source of the leak. Is this something that can be patched or is it replacement sink time?
 
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I can't seem to find my flex seal tape. Anything I can temporarily patch it with in case my brother forgets that I told him not to run water in that side of the sink?
I do have a bucket underneath it for now at least.
 
Put a piece of tape, black electrical tape, etc., in the sink over the holes to cover them temporarily. Clean the "holy" area with alcohol or some other sort of solvent to assist in the tape's temporary adhesion. Used chewing gum may work in a pinch. I recommend Hubba Bubba Bubble Gum.
 
I accidentally put a 1/2-inch cut in the bottom of a galvanized 3-gallon bucket. I "fixed" it by spraying some black flex seal on the inside of the bucket. That was around 8 years ago and I use the bucket whenever I wash my cars. The fix is still holding. Try using the spray stuff...
 
Great idea but, in reality, I'd like to do a forensic analysis of why the stainless failed in the first place. Manufacturing defect of some bad stainless steel, etc?
Cheap stainless. Probably had iron impurities that eventually rust out and leave a small pin hole.
 
In fairness, the sink is almost 40yrs old and it has taken a lot of abuse. It was a disgusting mess when we came back & evicted the deadbeat tenants. Looked like it hadn't been cleaned in 10 years. Stuff gets dropped in the basins- had some things break in there. I had to really scrub the basins down and I think I wore them down a bit.

My friend said he wants the old sink when I replace it so he can patch it and put it in his house since it's deeper than his current sink.

No chewing gum around. I despise gum. Get that from my father who got it from his father. I spent a lot of time in school wanting to turn around and slap the daylights out of students behind me chewing gum loudly. It actually made my father's blood pressure go up. When he was in the hospital I had to leave a note on the door for the nurses asking them to please spit out any gum before coming in as it would make his blood pressure go up. Fortunately, they were kind enough to comply when I explained it. They had taken his bp but the nurse was chewing gum & it aggravated him. She apologized when I mentioned that gum was a stressor for him.

I've tried the flex seal spray many years ago and it was garbage. It lumped up and peeled. Not good for a surface that will have utensils moved around on it. Might work from the underside though. I need to look for my flex tape-- but worst case they have some at Walmart. I wonder if I can tape the noise dampener back on when it dries out (over a layer of the flex tape).

Looking at this sink https://www.lowes.com/pd/KOHLER-Toc...e-Commercial-Residential-Kitchen-Sink/3616122

I saw another one that looked nice but it was 20gauge and I don't need thinner steel. I'll still look around a bit. I need to replace my faucet eventually but I can't find one with a single lever that can hook to a portable dishwasher. Right now I have one where the spout is in one hole, handle is in the hole to the right, sprayer to the hole to the right of that, and the hole to the left of the spout has some sort of soap thing that isn't hooked up. I'd really love to have the handle be on the spout in an easy to reach spot. I'm not fond of the pull-down sprayers. But, right now the sink is the priority. I'm considering getting a new sink strainer as well.
 
No chewing gum around. I despise gum.
I despise the particular breed of gum chewer that seems to consider the sidewalks ands roadways the only place possible to deposit his or her used gum. I was cursed at birth with the uncanny ability to seek out and find every piece of gum thrown away like that and have it attach itself to the soles of my shoes and deposit it on the carpeting in my automobile or my home. Much like reformed smokers are the most intolerant towards smokers, reformed gum chewers may be the most intolerant of chewers. I am much more tolerant of those who put a "pinch" between their gum and cheek for some strange reason.
 
I've never liked gum. I was ecstatic when I moved to Singapore and found out that gum was banned there (because people would stick it in the doors to the MRT and it stopped them from closing properly). Plus it was just disgusting when people spat it out. Is it really that hard to keep the wrapper, spit it in to the wrapper, and throw it in the damn trash? LOL.

But I digressed.

I went to the store and got a metal wire brush, waterproof gorilla tape, metal washer with small hole & jbweld. I found some alcohol swabs in the bathroom & got out a toothpick and flashlight. Cut a piece of the gorilla tape to size and set it aside. Took the noise dampening pad & saw it was still sticky so I stuck the washer to it and test-fitted it to make sure the metal on the washer would cover the hole. Scuffed the washer up with the wire brush (as the instructions said it needed a rough surface for better grip). Thoroughly scrubbed and cleaned the bottom of the sink & used the wire brush on it. Wiped both washer & underside of sink with alcohol swab. Used the round plastic cover from the top of the gorilla tape as a mixing surface, poured the stuff out equally, mixed until it was consistent, spread it on the washer & a little bit of the pad, smeared some of it on to the underside of the sink directly with the plastic it was mixed on, stuck the pad with the washer to the underside of the sink-- making sure metal covered the hole, and turned to mess with the gorilla tape. Pad fell off but washer stayed, struggled to get the clear plastic off of the gorilla tape for a few minutes & finally got it to come off so I could put the pad back up and put gorilla tape over it and firmly pressed & rubbed to get it to sit tight without any bubbles that I could feel.

Hopefully that will take for awhile. I think maybe some kind of metal skewer might have put the hole in the sink, but I'm not sure.

After cleaning it seems the two holes merged into 1. Either that or I had double vision. LOL. In the lighted picture the sort of white-ish spot is the hole.
Hole with light shining through in the dark.
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1639277575171.png

I smoothed the tape down more after this. Will go back and doublecheck and smooth it again if need be. I don't bend well so I had to get on one knee and had trouble getting back up. LOL.
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My supplies:
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I hope you're right. I don't want to have to replace that thing anytime soon. A deeper sink would have been nice, but reviews of the one I liked said it scratches very easily.
 
If you were using flex seal spray, it would also go on the underside, so moving around utensils would not be a problem.
 
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