How to tighten this sink nut?

Question

My bathroom sink’s faucet is loose on the countertop. Underneath there is a nut going around the drain pipe, recessed into a barely-larger hole cut in the wood supporting the counter. I cannot think what tool would support wrapping around this thick pipe, going into that tiny hole, and sticking to the shallow edges of the nut. How can I tighten this?

Edit: I was wrong. The nut pictured above is for the sink drain, not the faucet. The faucet connection is buried back where I cannot get to it. Still interesting to know how I’d tighten the drain, but does not solve my loose faucet.

As you can see from this second picture (white is vertical drywall, plywood is horizontal), the installation was not stellar. The faucet comes down behind the drywall somewhere.

Edit 2: For those interested, here is the sink and faucet from above, and (having taken off the front of the cabinet) better shots of underneath, and where the water lines go up behind the drywall.

Answer 1

If your only objective is to tighten the drain:

1. Remove the trap
2. Remove the square grate above
3. Use a basket wrench to attempt to tighten the drain from above.
4. If the tail piece turns with it, try grabbing it with your hand. If your arms aren't long enough you'll need an assistant.
5. If you need more strength on the tail, get a strap wrench, or fake one by wrapping a cut up bicycle inner tube around the tail and using channel locks. Either way be gentle ... the tail is soft and fragile.

You may either turn the basket and hold the tail piece, or the other way around. One way may be easier.

The tail piece is screwed into inner threads in the bottom half of the drain so the above ought to be enough. If the top and bottom halves of the drain are seized together you'll have to remove and replace the whole thing. But if it has become loose it's probably not seized together.

If you want to remove the drain

Follow all the steps above but turn the other way. You may however find that the tail piece will unscrew from the drain. It seems to be screwed in to the drain's inner thread. Like most drains, it's probably firmly stuck in there but if you're (un)lucky it will come out, and you'll be left with just the stubby drain sticking out from the wood.

Then:

1. Try the strap wrench or inner tube on the drain itself. There's not much sticking out and you don't want to damage the threads but it's worth a shot.
2. If that doesn't work you can grab the bottom of the drain from inside it using an expansion wrench or a drain key or a cam wrench. Pick one that you think might be useful for at least one more project in your lifetime. :)
3. If the parts are really seized up use a mini hacksaw to cut the drain in half from the inside, being careful not to damage the sink. Then replace it. Again, if it has come loose, that's a good sign you won't have this problem.

Or do it the way it was probably installed:

My guess: After you remove the tail piece you can slice through any silicone or glue holding the basin to the counter, remove the entire basin, replace the drain then put it back. That may be the easiest approach especially if the tail piece can be easily removed with a strap wrench.

Replacing the tail piece

I suggest you replace the tail piece with a more typical one that uses a compression nut on the drain's outer threads, rather than one that screws into the inner threads. Because ..... it's a lot easier to remove later and less prone to seizing up.

Answer 2

Make one.

I made a "socket" using some suitable metal pipe and a file. make it long enough and you can turn it with a wrench or drill holes and put a bar through.

If you have a Dremel or similar then it will make the filing easier.

Answer 3

The appropriate tool is called a "Basin Wrench" You can find it at any big box store or plumbing supply. The wrench head is usually on a pivot and is spring loaded. When you use it, the open "claw" part should be oriented to "pull" around the nut.

Edit: actually in your case the nut appears to be recessed into the wood subcounter? In that case you will likely need to remove the entire sink to tighten it. When you do that consider making the hole slightly larger. You might need to use a screw driver and a hammer to lightly tap the nut open or closed, unfortunately.

Answer 4

I suppose they attached the drain pipe and the faucet to the countertop and attached (worst case glued) the assembly to the furniture body.

The regular way would be to disassemble the entire thing and do it right.

The "trickster" way would be to somehow tighten those things. For the drain:

• I would see if I could fit in a tubular wrench somehow.
• Perhaps enlarging the hole in the OSB-sheet (with an dremel or oscillating multitool) until you can fit a basin wrench or said tubular wrench.
• Fabricate your own "bended fork wrench". (Assuming your metalworking skills are better than my drawing skills)

For the faucet:

• The part marked in red seems to be the fixing nut. Remove the spider webs and verify. Perhaps you can use a ratcheting wrench to tighten it.
• Observe it the "collar" in blue moves if you rotate the faucet.