Toilet-tank leak? ? ?

[Ray]

An odd problem: Our toilet-tank has developed a leak which seems to come from noshre. From observation the slow drip seems to be coming through the porcelain itself, although there are no cracks are holes that can be seen.

It most certainly doesn't come from a pipe, because the area all around the bulls-eye of the leak remains completely dry.

Is this possible that the water could be seeping through a porous procelain?

If so, would smearing the area with caulking compound, inside and out, stop the leak?

[AZ Nomad]

How old is the toilet? Usually what goes are the seals around the tank water output to the bottom assembly and the seals around screws holding them together. Replace the seals; if that doesn't help, replace the whole toilet. It just isn't worth putting any more effort into it when a new toilet can be had for $130 complete.

[HeyBub]

Uh, no. Porcelain is not porous. Think coffee cup.

There are only two possibilities (absent a crack). Where the water supply enters the tank and where the water drains from the reservoir into the bowl.

My money's on the latter.

[AZ Nomad]

and the seals around the screws that hold tank to base.

Or a crack especially if the screws have been overtightened.

[Rudy]

The big box stores are now selling the 2 pieces separately..if its a "normal" color, you can just buy the tank & Git 'er Done

[Mikepier]

If its humid in your house, and the water entering your tank is cold, it will condensate which will eventually leak on the floor. A good way to test is let the water in the tank get up to room temperature or pour a little warm water in the tank.

[salty]

With the onset of warmer weather, are you sure this isn't just condensation sweating on the outside caused by the cold water filling the tank?

[Limp Arbor]

Winning answer!

[AZ Nomad]

By the time it's leaking like that, you probably have a toilet old enough to have a tank three times larger than what is legally available.

[jonnmarcy]

it is not leaking through the porcelin, please describe the area that the leak is visable

[Oren]

Fixed a toilet a couple of years ago. The leak was difficult to detect. Just sitting there full of water the toilet would not leak, at least to the eye or with paper towels on the floor to locate the leak area.

Wiggle the tank slightly and see if the leak is around the tank bolts and rubber washers. I found the leak by accidentally bumping the tank during other work. Apparently, the toilet would leak when people used it and perhaps bumped / flushed the toilet. Just the small movement caused the tank to leak.

It this occurs, replace the tank bolts.

[Ray]

Since posting I found the source -- a hairline crack in the tank.

Is that something I can seal with caulking, or should I replace the whole thing?

it is not leaking through the porcelin, please describe the area that the leak is visable

[dpb]

...

You may be able to stop the leak temporarily but if it is cracked it is liable to fail catastrophically w/o warning in which case you have a big problem--particularly if it happened to be while the house is deserted for a full day at work, etc., ...

Replace it.

--

[Ray]

Since posting I found the source -- a hairline crack in the tank.

Is that something I can seal with caulking, or should I replace the whole thing?

[Oren]

Scratch the latter on a tank-n-bowl one piece toilet.

[AZ Nomad]

Maybe use epoxy injection? Maybe you can use a plastic liner, glued in place with holes for the water supply, tank bolts, and water outlet and thus achive a complete kluge?

Just replace the damn thing. Is your time worth nothing?

[k]

If you can find some water glass you can make a permanent repair by just sloshing it on the inside and brushing on more carefully on the outside. It's quite invisible. I have a tank that took a major league crack 20 yrs ago and sealed it thusly. If it was a normal color that I could match to the tub and sink I probably would have replaced it, but it's a Rheem fixture and not made anymore. It's a rather unique color, too. Fixing it was my preference.

I would think you'd also have good luck with something like gorilla glue on the inside only. I don't know where you'd find water glass these days, but if there's an old-line farmer's type hardware store around your area, that would be a good bet. I'm sure you can find it by googling either 'water glass' or 'potassium silicate'. Maybe just ask a plumber.

Keith

[Oren]

Best answer given.

"liable to fail catastrophically" just my luck is when, well you know! I'm sitting down one the job.

[salty]

Absolutely replace it. I would recommend that you shut the water off and empty it right now. Tonight. If the tank should break, not only will it dump a lot of water on the floor, but the incoming fill will be running nonstop, flooding your home. Lots of damage possible.

[Norminn]

No........catastrophically is when nobody is home and the house is flooded. BTDT.