Leaky Yorkshire Union

[fidom]

In 40 years of DIY I have accumulated various spare fittings of various ages. Yesterday I was doing a modification to cure a leak and managed to create a bigger leak! I used an old 15mm solder ring union / coupling. My uncle ( a former gas fitter) used to recommend you add a bit of extra solder to these after you see the ring of solder appear, so this is what I routinely do. As this fitting is of indeterminate age it may contain leaded or lead free solder but the stuff I added was lead free. The joint leaks and I'm wondering if it was due to a reaction between incompatible types of solder? There is a complete ring of solder at both ends. This is my first time using lead free solder as I ran out of the lead type. I now live in Croatia where they only sell end feed fittings, so that is mostly what I've used.

 

[CBW]

Not something I’ve heard of, so I’d say there’s a discrepancy in the fitting and or pipe, or there’s a minute gap somewhere. Is it possible to just cut it our and replace using new fittings?

 

[Madrab]

Invariably when a soldered fitting leaks it's usually down to poor prep, heat not correct or incompatible solder/flux. Flux is supposed to clean the surface but never does the job right. Solder ring fittings these days don't need extra solder, plenty of solder in the fitting to do the job and it can end up introducing too much solder internally causing a restriction in the pipe.

If the fitting is old, it's important to also clean the solder ring inside the fitting before it's used with a scotch pad, as that can oxidise over time.

If you can empty the pipe of water then de-solder the fitting and then clean the pipe with a cloth and a little flux and it will end up tinned ready for the new fitting.

 

[fidom]

I tried adding some extra solder and it is no longer leaking. The pipe one end was plastic coated copper off a coil and I suspect it is slightly undersize. When I tried a compression olive on it, that seemed a sloppy fit.