Hi there everyone,

I'm installing a manifold into a shower space, and when I charged the lines, the hot side began to show bubbles and weep at the threads of the tailpiece.

http://personal.schwim.net/images/share/tailpiece.jpg

Reading the instructions during assembly, I noted that there were no instructions concerning any kind of paste or tape to apply, so I assembled it with nothing, assuming that the tapered brass male/female fitting would make the necessary seal. It seems to have worked on the cold, but not the hot, so now I'm worried about both. I don't want to just throw some dope at it, because I'm afraid that over time, it will fail.

What do I use to make this seal? Any help would be greatly appreciated.

Thanks,
Json

Quote:

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Originally Posted by schwim

Hi there everyone,

I'm installing a manifold into a shower space, and when I charged the lines, the hot side began to show bubbles and weep at the threads of the tailpiece.

http://personal.schwim.net/images/share/tailpiece.jpg

Reading the instructions during assembly, I noted that there were no instructions concerning any kind of paste or tape to apply, so I assembled it with nothing, assuming that the tapered brass male/female fitting would make the necessary seal. It seems to have worked on the cold, but not the hot, so now I'm worried about both. I don't want to just throw some dope at it, because I'm afraid that over time, it will fail.

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Those are ground joint unions -- No doping is required.

Just try snugging it up a bit more.

I can't tighten it anymore without fear of breaking the mount, so I'll pull it apart and see if maybe I got some crud stuck on the mating surface.

Thanks,
Json

The joint at the bottom looks like it could be a NPT (National Pipe Thread). It's a tapered thread. It does need teflon tape or pipe dope to seal properly applied to a clean surface.

The upper joint just needs to be clean.

I'm a firm believer in thread lubercants to prevent seizing on the threads of the second type of joint. There should be a small tube of some non-hardening stuff. I use it on the screws on stem seals too.

As Growler pointed out, this is a ground joint union and needs no pipe dope on the union joint. However, keep it simple correctly advised using Teflon tape on the lower threads but not on the top threads. I don't agree. ALL THREADS should be taped if they contain pressure. I would check the ground joint for any trash the may be on the face and try again. Good luck, Tom

Speedball:

When is the last time you saw teflon tape on a garden hose or a washer hose? With your reasoning, you'd use them there too.

Note I did recommend something to facilitate removal, not sealing for the upper joint. I use the same lubercant on drain lines too. I'd use a silicone based grease for "O" rings and the ball joint.

Quote:

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Originally Posted by KeepItSimpleStupid

speedball:

When is the last time you saw teflon tape on a garden hose or a washer hose? With your reasoning, you'd use them there too.

Note I did recommend something to facilitate removal, not sealing for the upper joint. I use the same lubercant on drain lines too. I'd use a silicone based grease for "O" rings and the ball joint.

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Sorry I should have specified NPT pipe threads but since hose threads aren't pipe threads you don't tape those.
I repeat, All pipe threads should be Teflon Taped. However, your advice on using silicon based grease for "O" rings and ball valves is right on. Regards, Tom

Hi there guys,

I cut my backing plate apart with a dremel so I could get to the collar nuts without taking it apart, pulled the hot apart, checked for cleanliness and reassembled, tightening maybe a 1/32 more of a turn. I pressured the lines, and ran them for a minute each. So far, no leak at all.

I used pipe dope on the lower fitting(cpvc to brass), but nothing on the top. If I understand you guys correctly, since it's not NPT, I'm OK, right?

Thanks very much to everyone for your replies,
Json

Yes you should have Teflon taped the pipe threads and not use any pipe dope on the ground joint. I should have been more specific when I advised taping ALL THEADS. Keep it simple was right on to correct me. Good luck, Tom