On Nov 17, 7:36�am, George wrote:
We have a bathtub that has a drum trap - which appears to be lead, as do
the connecting pipes. �(The stack is cast iron.) �The trap is leaking.

I'm thinking to cut the lead pipe on the stack side of the trap, use a
rubber coupling to join that end to PVC from there to the tub. �Is there
reason NOT to do this? �The alternative would be to unsolder the lead
pipe from the stack Y, and connect the PVC there. �This looks like it
would take big heat, and might never get clean enough for the new joint
to seal well.

TIA,
George

replace drum trap with PVC, replace the part that fits on the tub too,
brass is better there.

after repeatred problems over many years i had a plumber replace all
the lines from tub and sink too basement.

the cast iron was clogged and rotting, and had a crack, what remained
of copper was clogged, it was a mess, that damaged kitchen cieling
below. our home was built in 1950

for me the plumber was a good choice i dont want to see that cieling
cavatity again

the plumber managed to increase the slope of the sink drain, it emptys
better