Leaky copper joint.

[PVR]

I am totally finishing my basement (seven rooms) including installing a bathroom. I want to be able to say I did it all myself. I have installed about 50' of half inch copper with seven stopvalves and about 25 joints (straight, T's and L bends). I used presoldered joints. With some trepidation I opened the hot and cold stopvalves and found that just one of the L joints had a very slight leak. The whole system is not an artistic success but it is functional (except for the leak). The L joint is about 2" from one wall and 3" from another (it is in a corner) so that seeing behind the joint is not easy.

How should I deal with this? I know I have to drain the water from that part of the system. Do I need to remove the L joint and replace it? Would it be possible to apply flux to the two pipes and then add extra solder?

Would appreciate any suggestions.

Peter.

[Tony Hwang]

Hi, Looking behind the joint is easy with dentist mirror. IMO, best thing to do is to remove the joint and redo it with new one. And if this is your first time at it, even if there is no leak now.... Good luck.

[Tony Hwang]

Hi, Actually plumbers use high compressed air for checking leak when they finish a project. Clos all the valves, faucets, then pressurize the eintire run, then leave it couple days. If there is pressure drop, they have to find the leak before they can commission the system. Real SMALL leak can take a day to produce a drop of water.

[Toller]

Sure, take it apart, clean it, reflux, add solder. Try not to overheat, or you will melt other joints. Odds are it wasn't clean enough the first time.

[NickySantoro]

Would it

yes

[EXT]

Clean as much of the area as you can with steel wool or sandpaper especially the edge of the fitting and the pipe area close to it and flux it well. When you solder try to build a fillet around the edge of the fitting so that solder bridges the gap between the pipe and the fitting similar to a cove shape. I find if I do this when soldering I never have a leak, if I don't there is a good chance there will be a slow leak.

[Sacramento Dave]

Actually what we do is fill the system with water then put a Hydrostatic pump on it pump it up to 125 PSI. It is a little more work to fix a leak put you find them faster. Plus it is much safer. Some systems do require air only to test them. You only about 15 psi to find leaks, with soapy water.

[Sacramento Dave]

Drain the water out of the line you might have to cut a coupling in You can try to heat the area then while hot add flux then add solder. If that works take the rest of the pre soldered fitting place on floor tap with hammer until flat close to $2 a pound for scrap.

[Tekkie®]

PVR posted for all of us...

Asked and answered MANY times - do your own research.