Plumbing – How to fix a leaky spigot on a rain barrel

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.

Tighten the joint slightly.

Pipe threads are tapered - the PTFE thread tape (or pipe dope - I'm currently more of a fan of PTFE pipe dope than of PTFE thread tape, though I used to be a big fan of the tape as opposed to old-style dope) provides a seal for the "helical leak path" (the fact that the female threads are a bit sharper than the top of the male threads) and some lubricity for easier tightening.

A slow drip type leak is often just a 1/4 turn from not leaking.

If you take it apart, you need to clean off the remains of the old tape and apply new tape (one reason I now prefer the modern dope - you can just add a bit more, with no need to clean off the old, and you don't have all the tape shreds to deal with.) Excessive thickness of tape won't help the seal - more is not better.