Have a metal drain pipe coming out of wall for bathroom sink. Plumber put on a no-hub coupling for me (I'm replacing a sink and cracked the old pipe when removing old sink). Anyway, I'm hooking up the PVC drain line and trap but have a leak at the coupling. Is there a trick to connecting these two different types of pipe? Or do I just slide the PVC into the coupling right next to the metal pipe and then crank down on the coupling?? Seems like I would need something more secure between the pipes...

Hi Gator:

What kind of pipes are you using? Copper and PVC? If so, you could use a fernco coupling... see 1st image or a no-hub clamp (see 2nd image), however, a better job would be to use a copper x PVC shielded clamp... see 3rd image. This clamp acommodates the differences between the pipe thicknesses. They are available at home depot or any plumbing supply store.

The other clamps can be forced down to match up, but don't usually work very well in the long run.

If this is a glavanized drain pipe to PVC then any of the clamps will work fine, even the shielded clamp as you would order it as an 1.5" shielded clamp.

Back to you...

MARK

Here is the trick, when you pay a plumber to do a job you have the right to do a "call back" Just ask him to fix it the way oit should have been done. Metal pipe is not perfectly smooth and can get worse with age. Or hit the pipe with plumbers cloth and then grease it a bit with plumbers grease.

Looks like it's galvanized coming out of the wall (house is 50+ years old). I'm hooking up to PVC in the trap (though I can go with something else if it's better). Looks like I have the rubber Fernco-type coupler as well. Do I simply put the coupler between the pipes and ratchet it down?

Clean the pipe up as Ballenger suggested and then ratchet/tighten the clamp down to both pipes. If that fails you can call the plumber back or purchase a better clamp from home depot.

Funny thing about the rubber ferncos... they are really made for underground plumbing but are almost always used for repair plumbing. Buy the 1.5" shielded clamp if you have any more trouble... ;)

MARK