fixing a leaking soldered joint without separating the joint

[dragonfly101]

I've been fitting some pipe this weekend using pre-soldered joints, and out of the 20 I fitted I have one that is leaking (a crossover). It's in a tight spot and I'm wondering if it would be possible to fix without separating the joint.

The reason I don't want to separate it is that I'm concerned about putting strain on the other soldered joints nearby (which aren't leaking).

If I just cleaned the joint as it is, applied flux and solder is that likely to fix it? Will solder get inside the joint and seal it, even though I've only got the flux around the outside of it?

All the advice I've found so far is to heat the joint and separate it, then allow to cool, clean, apply flux, resolder.

One other issue is that because I bought pre-soldered joints I didn't buy any actual solder, and I can't find any shop that sells this in small rolls - I'd have to buy far more than I need! Also, I've only ever soldered pre-soldered joints (for the first time this weekend), is soldering joints with actual solder easy to get right the first time? I already have spare pre-soldered crossovers and straight couplers, so I could just cut the leaking crossover out and put in a new one - but this would mean adding straight couplers either side - so yet more potential leak points.

 

[doitall]

If, you can get all the water out you could heat the fitting and brush self cleaning flux around the joint then add solder. May work.

 

[Agile]

I have often repaired joints which are not fully soldered using electrical multicore solder.

The flux in that solder seems to be more effective at cleaning the joint than plumbing solder.

Using it would also get over your fear of buying a whole reel of solder when you only need a small bit.

Tony

 

[dragonfly101]

interesting, electrical solder, I could give that a try. I can drain the pipe no problem, although it'll still be damp inside of course.

 

[doitall]

Laco flux and lead free solder is the best way, it will work or not depending on the luck and why it leaked in the first place.

 

[kbdiy]

You need to heat the pipe gently after draining down to evaporate all the water from the joint and adjacent pipework. Then let it cool, clean up, flux and re-solder. Has worked for me when awkward joints fail.

 

[dragonfly101]

thanks everyone, so it sounds like it's worth a try just cleaning and soldering the joint as it is. If that doesn't work I'll cut out and replace.

 

[mogget]

Laco flux and lead free solder is the best way, it will work or not depending on the luck and why it leaked in the first place.

I've used this method in the past, works quite well normally.