1/2 inch. Leak is on the side of a horizontal pipe.

  • 2
    The hard part is getting all the water out. If I have a leak I will pull the joint apart and take some white bread (no crust) make 2 balls and stuff them in the pipe to keep the water out, then re sweat the pipe. Pull the aerator / screen on a faucet or the bread goo will plug it up and flush the goo out the faucet. I was taught this many years ago when we still used lead solder and it is much easier than the non lead solder. – Ed Beal May 5 '16 at 23:21
  • Possible duplicate: How do I "fix" a bad sweat (solder) joint – BMitch May 6 '16 at 19:21

Adding more solder almost never works, because the problem is almost never "not enough solder" - the problem is almost always poor pipe preparation, where some part of the pipe is not cleaned and fluxed (separate things - physically clean, then chemically clean via flux - flux can't cure macroscopic dirt.) Overheating one or both parts when soldering can also cause this, by burning away the flux and oxidizing the pipe.

A properly prepared joint will wick solder all around by capillary action. An improperly prepared joint will never wet where it's improperly prepared, so it has to be taken apart and both the pipe and the fitting need to be properly cleaned and refluxed before reassembly.

Excess solder (as you might add while trying to fix a leak improperly, on the theory that if some is good, more must be better) is not benign - I have personally hunted down a pipe that had pressure when there was no flow, but almost no pressure when the valve was open; having eliminated the valve as a cause, I took the pipe apart joint by joint, and found one elbow almost filled with solder, with just a tiny hole water was making it through (that's inside the pipe, where there was supposed to be a 1/2" hole.)



The proper solution is to:

  1. Drain the pipe and open a valve somewhere to vent the vapor
  2. Heat up the joint, and pull it apart.
  3. Clean fittings to remove any remaining solder.
  4. Apply flux to both fittings.
  5. Solder the joint.
  • Drain the pipe and open a valve somewhere to vent the vapor... – gbronner May 6 '16 at 12:59

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.