I've got an older home and the prior owners never proactively fixed anything and if something broke, they fixed only what they needed to as cheaply as possible.

I needed to swap out sink hardware in a bathroom with a double sink. One of them wasn't a problem but the second one still has a metal drain pipe going into the wall which I now need to swap out. What is the best way to cut this pipe and connect it with PVC so that I can finish up this drain? I believe that the metal drain line is a smaller diameter than the sink drain and not sure if that will create an issue or not. I've been looking at compression couplings but I am not sure if that is the best way to do it or not, especially with a potential diameter mismatch.

The prior owner had already joined the metal pipe on the other sink with PVC so I didn't run into the issue there.

Metal Drain


Other sink with metal to PVC using black compression sleeve?

Easiest way is to copy what they did on the other drain. Choose a straight length of the metal pipe, cut it with a sawzall then use a compression sleeve to connect to the pvc. It's not pretty and those sleeves do deteriorate after a while, but it'll do the job.

Agreed. I'd cut off the downward bend of the metal pipe and then use a Fernco coupling to go to PVC trap.