I had a leak between the toilet tank and bowl. I removed the tank, but during the process one bolt snapped due to excessive corrosion. So now I have one bolt hole in the tank cleared and cleaned, and the other with a corroded bole head stuck in the porcelain tank hole.

I have tried to remove the corroded bolt head by:
- gently tapping the broken bolt stem from the bottom of the tank (while not cracking the porcelain tank)
- attempting to turn the exposed bolt stem using channel locks
- soaking the corrosion over night with penetrating oil (and repeating steps above)
- trying to drill out the corrosion in the hole between the bolt and surrounding porcelain.
with no luck. I now have more penetrating oil soaking on the corrosion.

I found that Crane no longer makes a replacement tank for that model, so if i crack my tank I will be forced to replace the whole toilet. My current approach will be to continue soaking overnight hoping that eventually the corrosion will loosen (but I don't know how long that might take, or if it will even work).

Any insight would be appreciated

Is there any space between the tank and the bowl? If there is and you can get to the bolt then try using a mini hack saw to cut the bolt in half.

Never mind. It sounds like you were able to remove the tank but the bolt is still stuck on it.

The bolt snapped when I was removing it, so I have the tank off, but I cannot remove the corroded bolt stub fro the hole in the tank.

You can try turning it, but the corrosion in there may bind up and create a wedge....which will then crack your tank. You might even try tapping it with a small hammer. Tap it one way, then the other. This may take a long time. Whatever you do, its going to require micro movements. Even tapping it back out will possible work. I'd let it soak in PB Blaster for an hour or so before trying. Then give it a good soak as you start tapping to see if it will work down into the situation a little. Like I said...TINY movements are the goal here.

Thanks

I'd have to see it to understand the practicality of this, but I might take a dremel cutting wheel to it. Just start carefully cutting off pieces of it to get it as flush as I could, then maybe using a diamond cutting bit to bore it out, if there's any left. But if you're not handy with a dremel it could go really wrong. It could easily chatter off your bolt and chip or crack your tank.

Since they don't make that tank anymore, this tank has no future other than being replaced in total someday with a Federal low volume flush type aka 2-3 flushes type somehow we all "voted" for.

Thus, if you can install the tank with one SS bolt, then lifetime silicone in place anything else that might move or leak, then I would quit this adventure - fun as it may be - and begin a savings account for the new toilet. BTW, did you know that when remodeling, perfectly good 7-gal toilets are sent to the dump where DIY pick them up and illegally replace bad toilets?

If I understand correctly you have the bolt head in the bottom of the tank with the threads either flush with the bottom of the tank or sticking out.

If that's the case I'd try to use a reverse drill bit and EZ out on the bolt head to see if you can get it to move.

Is the tank removed from the bowl? Is there a gasket between the bolt & tank? Can you cut away at the gasket? If so then the bolt will come out.

If the bolt is directly touching the porcelain then good luck & continue your soaking method.