Leak at threaded connection

[Jedd De Lucia]

Hi, I am installing three valves in a new shower. This is a DIY project and I'm new to plumbing. I'm using a stack of Kohler valves. In the middle is a temperature/volume valve. Hot and cold inlets on the side and 2 outlets on the top and bottom. Below I'm installing a volume valve for body sprays. above there is a diverter feeding a rain shower, hand shower and standard shower head.

I have soldered the connections but the valves all have female threads. I installed copper threaded adapters with a short stub of copper pipe so that I could solder before connecting it and then solder the next joints further away from the valve, as the directions say.

I used pipe thread goop, or whatever it's called, for the threaded connections, not tape.

None of my soldered connections leaked (hooray!) but I do have 2 threaded connections which are leaking. What should I do? is there a better method of connecting copper pipe to thread? should I use a brass adapter instead?

Also, at this point what should I do? how can I get the threaded connection disconnected and fixed without taking everything apart? See pics attached. thanks for the help!!!

Final question, since none of my solders joints leaked, am I in the clear for leaks on those or will a bad solder work at first but fail after time?

 

[hj]

1. You probably CANNOT disassemble the threaded joints without taking at least some of the copper apart. (I would have soldered the male adapters into the valves).
2. I have seen "bad joints" hold for decades, then fall apart with somewhat light contact by some object.

 

[Sponsor]

 

[Jedd De Lucia]

Thanks HJ,

(I would have soldered the male adapters into the valves).

How would I solder the joints in? The Kobler instructions specifically say not to solder directly to the valves because they can be damaged. There are no cartigest to be removed.

Is there anyway to test the integrity of the soldered joints that I have done?

 

[Terry]

I would remove what is needed, and start over on the sections needing it.
Normally a good soldered joint stays good.
If you reheat a joint, it's best to pull it apart and reflux it.
A better seal can be made with tape and dope together. Normally I just dope them and tighten them down really good.

 

[Jedd De Lucia]

Thanks!

So with two threaded connections opposing each other (see pics above), how do I tighten down these threaded connections while ensuring that the valves both end up plumb to the wall.

Are copper male threaded adapters okay to use with brass female threads?

 

[Dj2]

Quote: " but I do have 2 threaded connections which are leaking. What should I do? is there a better method of connecting copper pipe to thread? should I use a brass adapter instead?"

I'd remove these two by cutting the pipe, 2" or 3" away, add teflon tape to the dope, re-install them reasonable tight (never over tighten, copper is soft), then add a coupling to the pipe and solder.

Make sure everything is dry.

 

[Terry]

Quote: " but I do have 2 threaded connections which are leaking. What should I do? is there a better method of connecting copper pipe to thread? should I use a brass adapter instead?"

I'd remove these two by cutting the pipe, 2" or 3" away, add teflon tape to the dope, re-install them reasonable tight (never over tighten, copper is soft), then add a coupling to the pipe and solder.

Make sure everything is dry.

Yes, the coupling inbetween does it.

 

[Jedd De Lucia]

Okay, by reasonable tight I'm assuming that this means as tight as I can get it using a 10" c-wrench by one hand with out cranking down on it.

What if I had previously over-tightened? Could I have damaged the brass with the copper male fittings?

How long do I need to wait before soldering near or running water through the theaded connections with the pipe dope?

 

[Dj2]

"Okay, by reasonable tight I'm assuming that this means as tight as I can get it using a 10" c-wrench by one hand with out cranking down on it."
You tighten with two wrenches, one holding the valve and one tightening the connector.

"What if I had previously over-tightened? Could I have damaged the brass with the copper male fittings?"
Yes, it could have happened, so inspect the valve for cracks.

"How long do I need to wait before soldering near or running water through the theaded connections with the pipe dope?"
If you are asking how long you have to wait to run the water after soldering, the answer is you can run the water immediately.
If you are soldering near the valve, remove the plastic parts (cartridge) so you don't over heat them. Again, use dope and tape on the threads.

 

[Jedd De Lucia]

Hi Dj2, I was asking how long I would need to wait before running water or soldering after using the pipe dope and making the threaded connections. The dope that I am using seems to dry out a bit, but not completely, I'm wondering if my leaks came from the fact that I ran water through the system only a few hours after making the threaded connections.

Thanks!

 

[Dj2]

Hi Dj2, I was asking how long I would need to wait before running water or soldering after using the pipe dope and making the threaded connections. The dope that I am using seems to dry out a bit, but not completely, I'm wondering if my leaks came from the fact that I ran water through the system only a few hours after making the threaded connections.

Thanks!

You can run water immediately. Use teflon and dope. If your pipe dope is hard, mix it with a drop or two of paint thinner, work it with your fingers and apply it all around the thread.

I will be very surprised if your leak returns, after all these dos and don'ts.

 

[Jedd De Lucia]

hi all, I have another question. The instructions for the rain shower call for a pressure balance loop which uses a 1/2" cross. See pic attached. I am having trouble finding one in copper and the brass ones are fairly expensive.

Could I just use a couple of tees and elbows and make something similar without using the cross?

Will the pressure even out as long as there is a loop or is it important to have the feed from the cross going through the center as the picture shows? I could still make one with a center pipe even if I used tees, it would be more of a double loop. Does it matter?