Slow leak from shower valve threaded joint

[Marc R]

Hi,
I've done lots of reading here before, but now have a specific question that some guidance would be appreciated on:
I'm new to plumbing and just plumbed a shower using all copper with soldered joints except for where the pipe meets the valve body, all four of those are brass threaded joints with tape going in to the brass threaded valve body. I had a couple of very slow leaks from the threaded joints going in to the valve body initially so I cut it out, retaped, and retightened those. Those leaks are gone. I had been worried about over tightening initially, but they are very tight now.
The new issue is this: I have the tubspout attached and a brass plug in the shower ear. There are no leaks with water running, but I pulled up the tub spout stopper as a way of checking the joints in the tub and shower lines and there was an incredibly slow leak from where these thread in to the valve body - I'm talking 5-10 minutes to form a quarter drop of water at the threaded joints, nothing dripping. Releasing the pressure and just running the tub spout normally the leak is gone. Having learned from the supply line threaded joints I tightened the shower and tub threaded joints quite tight using a wrench, to the point where I couldn't have done another full turn.
My question is this: is it okay to leave it as is since these lines should only see low pressure? Or do you have any suggestions on what could remedy the slow leak? I would remove the blocking, retape, and retighten but I don't think I could get them any more tight than I did already.
Thanks for the help and for all the other useful posts!
Marc

 

[Reach4]

Try PTFE tape and pipe dope both. Rectorseal #5 is one of the well-respected pipe compounds for brass.

 

[Sponsor]

 

[FullySprinklered]

Don't leave anything leaking.

 

[Breplum]

Don't leave anything leaking.

I agree, don't leave anything leaking. Sorry.
In fact, the better test is to screw a pipe with cap into both the tub and shower drop-ear elbows to check for leaks.

 

[Jadnashua]

In an enclosed area, constantly adding even a little bit of moisture can cause some big problems down the road.

FWIW, many (by no means all) of those threaded joints are dual-mode...they'll take a threaded connection OR, the inside of the valve body is sized to accept the supply pipe and be soldered directly into it. While you have to remove the cartridge most of the time before you can solder it, and getting the larger valve body hot enough to actually make a good solder joint will take longer, it is often more robust. But, threaded works. On some of them, especially some from China, the threads are lousy (dull cutter, so burrs, chips, often, not deep enough), so using both tape and pipe dope can help as a belt and suspenders sort of thing.

 

[Marc R]

Tape and dope worked perfectly, thanks!