The bathroom remodel and relocation of the fixtures calls for some re-piping in the basement, and also presents a good opportunity to add some shut off valves and create "zones" so that future work doesn't always require a whole-house water shut down.

I'm 100+ solder joints in on this project using lead-free solder and L copper pipe, and wouldn't ya know it the one leaker is the shut off valve itself. I wound up having to cut out the valve since the rest of the plumbing was made up (and no play in the pipes) and replace it with a spare 3/4 ball valve, a section of pipe and a repair coupling.

I de-soldered the pipe stubs from the old valve, mainly to save the valve for re-use, but also discovered an interesting post mortem. You can see in the first pic that the solder ran around the joint. In the second pic you can see a small section where the solder would not flow, and this is where it was spraying from. I'm pretty thorough on the clean and flux, but wondering if I missed cleaning this section, or if I overheated the pipe and boiled the flux out. Trying to figure out what went wrong here.

I'm curious as to how the section of the inside of the valve looks? Same area with no solder?

If you had inspected the joint after soldering, you would have noticed that the solder had not flowed all the way around. After soldering and letting the joint cool a bit, I wipe it clean and inspect the joint all the way around using a mirror if necessary, looking for that ring of solder at the joint. I will occasionally see that the solder has not flowed fully and reheat the joint after applying more flux and it almost always takes care of the problem.

As to your question, you might have overheated the joint since there is some blueing visible.

George I wondered if I didn't adequately heat the "back" of the valve, the part facing away from me. Usually if I see solder flow around and it forms a drip at the bottom, I know it penetrated the entire joint so I don't go back with an inspection mirror. Lesson learned here.

Vic, here is a pic of the valve and it looks like the same area didn't get the solder.



After I de-soldered it and let it cool I just tossed it on my plumbing bag...fishing it out for this pic, I recall hearing a loud POP when I was de-soldering it on the bench, and looking at it now I overheated the valve the blew the seal out of it.



I bought the valves from a reputable supply house, and they said the brand is Bluefin, but sure doesn't look like it. Only logo is what looks like a "W" on the side of the valve, Anybody know if I can get a seal kit for it? The valve was $17, hate to toss it. I like to use these ball valves with the bleeders because once you shut the "zone" off you can drain the pipes in the section that's turned off by the valve and makes future work easier. They stopped carrying these valves with bleeders in the local big box store, so having to order them online.





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IF it was my valve and I wanted to save it I'd clean the joint, put some flux on it and heat and add solder at the appropriate time/temp. Careful to not overheat. I'm guessing the new solder will flow onto the area that currently has no solder.

Also, place handle in a partially open position so any steam caused by trapped test water does not create steam pressure and blow out the seal, which is probably what happened with that one.

Ouch on the popped seal! Hope you can find a replacement seal, but not hopeful on that. I've heard about wrapping a small wet cloth around the valve area to keep the temp a little lower on the valve area while soldering/desoldering. But be careful of steam.
I too am redoing an empty house that froze with the water on. (Accidentally. She normally turned it off at main when she went south. This time she forgot.) Heat was turned off. 13 damaged areas not including the shower assembly. The cartridge was damaged and pushed out from the freezing. Thought we got lucky on that and got a replacement cartridge. Nope. There was unnoticed damage to the brass assembly. Took the 38 dollar cartridge back and bought a whole new shower asembly. We turned the water on and spot a leak. Turn off, and fix. Turn on again, spot, off, and fix. Repeat over and over. The surprise came after the hot water tank finally got a chance to fill up and then the leaks in the hot water pipes presented themselves.
Hope your soldering journey goes smoothly.

No, the valve was fully open with bleeder cap removed. this was the de-solder on the bench but always solder them in the same way. The plastic seals that go around the ball withstand heat well, and why it surprised me when it popped. I have the valve apart, the seals are super easy to replace IF I can find them....

Ouch on the popped seal! Hope you can find a replacement seal, but not hopeful on that. I've heard about wrapping a small wet cloth around the valve area to keep the temp a little lower on the valve area while soldering/desoldering. But be careful of steam.
I too am redoing an empty house that froze with the water on. (Accidentally. She normally turned it off at main when she went south. This time she forgot.) Heat was turned off. 13 damaged areas not including the shower assembly. The cartridge was damaged and pushed out from the freezing. Thought we got lucky on that and got a replacement cartridge. Nope. There was unnoticed damage to the brass assembly. Took the 38 dollar cartridge back and bought a whole new shower asembly. We turned the water on and spot a leak. Turn off, and fix. Turn on again, spot, off, and fix. Repeat over and over. The surprise came after the hot water tank finally got a chance to fill up and then the leaks in the hot water pipes presented themselves.
Hope your soldering journey goes smoothly.

I think hj was referring to water that could get trapped in the packing nut area if the valve is fully open. The steam generated pushes out one of the two seals.
When the valve is partialy closed, the steam can escape past the seals.

Ah OK! I didn't realize that water could get trapped in there, that makes perfect sense. I have always soldered these valves in the fully open position, but they are dry when they are new, so no chance of steam buildup. When I de-soldered on the bench, the valve had been in service (briefly) and that trapped water is what blew the seal out.
Thanks for the explanation, now I know to solder these in the partially open position!

I know this has been discussed before, but the higher temps needed for this lead-free solder give you a narrow window between melting the solder and melting everything else....

You are also correct, no parts for these valves, although they do sell bleeder caps separately for $0.35 each....but now that this valve is junk I have an extra!

Fully off or fully on, eiTher way can leave water trapped inside the valve body. Partially open is the only way to ensure no steam 'pressure inside the valve.

I have always wondered if a ball valve should be soldered with it fully opened or fully closed, and I have seen some debates by plumbers who did it one way vs the other. I never considered half opened, learned something new every day.

In the past I have always soldered fully opened whether it's brand new never used or not. My reasoning was the fully opened valve will let steam escape, but I also wondered if the valve is installed in a vertical and closed position, if I am soldered a joint above it, whether I may end up with melting solder dripping on the valve seal or ball, since being inexperienced I tend to put more solder than necessary as "extra insurance".

One more thing, I tend to think that a vertical joint facing down where the solder has to flow up and around is the most difficult to solder especially the side facing away from me, I don't know why it could be just psychological.