Cutting Copper Pipe near a collar

Question

I need to cut the extension off my tub spout pipe so I can put another spout on it. The original spout (which never worked right) is a slip-on type but requred about 6 inches of pipe. Whomever did it before just soldered on an extension with a collar to make it work. But now the new spout I want to put on won't fit over this collar because the receptacle in it is only 1/2 inch in diameter. My idea is to cut behind the collar, leaving about 1 3/4 inches of pipe left to slip-on to, which should be enough, but a pipe cutter won't work becuase of the uneven spot on the pipe (between collar and regular pipe) I though of using a hacksaw with a fine blade, but I've read this causes a lot of vibration and can damage other solder points, which are all in the wall, and would be a PITA to fix.

Answer 1

The simple solution is to put a wet rag around the pipe at the wall, (this helps to not melt joints you don't want to disassemble) and apply a torch or heat gun to the coupling ("collar") until the solder melts sufficiently to pull the coupling off (with pliers unless you like getting burned) and wipe the excess solder off the pipe quickly (while it's still molten) with a damp rag in a gloved hand.

That will leave you with a pipe stub with a negligible amount of solder on it, so a pipe cutter can be used normally if it's still too long, or the tub spout can be slipped on if it's not too long.

That said, it would have to be a terribly marginal solder joint elsewhere to be affected by hacksawing a pipe.

Protect the bottom of the tub before starting.

Answer 2

If your question is how to cut the copper pipe near an uneven spot on the pipe, then you might still be able to use a pipe cutter if you "repair" the uneven spot.

Since copper is a relatively soft metal, it is not unusual for copper pipes to get ovalized a bit during handling. Ovalization can be improved by using an adjustable wrench to massage it back into round if it's not ovalized too badly.

The way to do this is to set the jaws of the wrench at the opening the same size as the round pipe is supposed to be. Use a good section of pipe to do this. Now that the jaws are set, slide the jaws over the ovalized spot and spin the wrench around to attempt to squeeze the wider part of the ovalization back closer to the correct size. You may have to start with the jaws a bit larger than necessary and do it in several steps.

This works if the pipe was not crunched too badly. If the pipe was really smooshed badly out of round, then you will probably need to cut out the whole section of pipe to replace it.

Here is another answer describing this method.