A few months ago we had a serious point leak in a copper pipe near the wall shelf and electrical box inside the wall behind the bathroom sink. We expected to have to open, cut and solder the wall under the sink. Instead, we turned off the water, dried, and then cleaned the pipe with sandpaper and vinegar. We cut off about 1/2 inch epoxy putty, mixed it for about a minute, then shaped it and pressed it against the pipe at the leak. About 2 hours later, when we were sure the epoxy patch had set and sealed, we turned on the water. The leak was fixed, no cutting or soldering! Still fixed months later, no problems so far. The leak is still fixed. The putty is still working well and I'd be happy to use it again if or when we find another leak somewhere else in the pipeline. UPDATE: In 2011 the leak is back and we fixed it permanently with a new pipe. This plumbers epoxy putty has lasted over 3 years which is not bad for a temporary solution. Considering we are into well water this is even more impressive.