plumbing
What the heck is this brass fastener and how do I remove it? It seems to be holding down my bathroom faucet which I'm trying to replace.
All I can think is that center "hinge" maybe unscrews somehow? But I don't see any way to grip it, it doesn't have a shape I'm familiar with or that I know how to use with any of my tools (phillips, flathead, hex nut, wrench).
Go to your local hardware store and purchase a strap wrench:
The rubber strap wraps around and grips the cover. Then you rotate the wrench anticlockwise to unscrew the cover off the tap. The strap prevents scratching of the finish which would normally occur trying to unscrew the tap with the jaws of a regular wrench. There are also regular-style wrenches with soft jaw fittings that may also be used.
See this thread about how much to tape to wrap. Two wraps might be too little while 20 seems pretty extreme.
Some people like tape, some like compound and some like both. I gave up on reading about which is better because it just seems to be a matter of opinion.
Both are for lubricating and sealing. The "Pipe Dope" has a substance in it (sometimes hemp) that expands with moisture to further help prevent leaks.
Regarding how tight, you can definitely over tighten but if they are leaking I wouldn't hesitate to give another bit of a turn. You need to be particularly careful with compression fittings since they can be more easily over-tightened.
Best Answer
This is a toggle nut with some type of locking device extending down through it. It must be removed from above. Some type of cover on the faucet itself is removable. From there you will see the top of the bolt that is threaded into that toggle nut. unscrew that bolt and the toggle will drop away.