I had a leak in some old 1-1/4" drain pipe that eventually connected into my plumbing stack. Replacing a section of the old copper pipe with PVC pipe seemed the way to go so I figured I'd start where the fitting threads into the stack. Well let me tell you, after putting the heat on that fitting for almost 2 hours and a large pipe wrench, that thing would not budge. The lead in the plumbing stack joint above where I was applying the heat started to bubble so I figured I'd better stop there. Any ideas how to get the fitting loose?

HI Scobie...

Probably need two 2 foot wrenches here... one to hold the cast iron fitting and one to loosen the copper fitting... ;) You could also add a "persuader" to the wrench you are using (say a two foot piece of steel pipe), but you could end up breaking the stack so I would probably not go that route here.

Another approach would be to heat the copper fitting and remove the copper pipe... reinstall new pipe and solder.

With that being said, however, if the fitting is still tight in the stack I would recommend that you simply cut the copper pipe about 3 inches off the fitting and use an approved COPPER X PVC shielded transition clamp... sold at all plumbing supply stores (and some home improvement stores)... see image below. Do NOT use the all rubber with 2 SS band clamps... not approved for use here.

If you use the shielded clamp you need to be sure to test the copper/cast connection at the stack real well before closing everything up (just run tons of hot and then cold water). This will also test your shielded clamp transition as well.

Care to discuss more? If so, let me know, OK?

Mark

Thanks for your help Mark. My biggest fear was breaking the stack but I wouldn't have been able to put a big pipe on the wrench for leverage anyway since it is pretty tight quarters where I'm working. Also, the hex nut on the copper fitting is not very wide so I only can get about half of the pipe wrench on it anyhow, so I'm sure I'm losing a lot of torque there. Thanks again.

Agree with Mark, "Cut and Paste" process. Actually Cut and Join is the proper term but C&P is more techie -LOL

Well Thanks again. I have some Fernco couplers on there for now so the leak is stopped until I find something more permanent. As you may or may not know, 1-1/4" pieces are hard to find since everyone is using 1-1/2" now but that's what they used for our house 50+ years ago. When I have time, I will check what some plumbing supply places have or the internet since the big Home Improvement stores are phasing out a lot of copper pieces and especially 1-1/4". That being said, I'm still not giving up removing that fitting. Do you think if I periodically soak it with WD 40 that it might loosen it up?