Extending cast iron drain pipe at cleanout

[Paul Riddle]

Hi everyone,

I'm running a new PVC drain line (for a kitchen sink) and would like to tie it into some existing cast-iron drain pipe in my basement. After much consideration, I'm thinking that the easiest approach, if possible, would be to extend the existing pipe at the cleanout. However, never having worked with cast iron pipe before, I'm wondering about the best way to do this. For reference, I've put a few pictures of the existing drain pipe at

The pipe diameter is 6", and the cleanout appears to be a standard bell with a threadded ferrule caulked in place to accept the cleanout plug. Is this how most cast iron cleanouts are put together? If so, Would it be possible to pry out the (presumably lead) caulk, remove the ferrule and insert a Fernco donut fitting to accept new PVC pipe? If not, I suppose I could adapt the new pipe to the threads for the cleanout plug, although I imagine that would be less desirable. In either case, I want to add just enough pipe to glue on a PVC "Y" fitting to accept a new 2" drain stack along with a new cleanout plug. Does this sound doable?

Thanks for any thoughts, Paul

[Speedy Jim]

Yes, that is a brass ferrule caulked (leaded) into a std bell. To get the ferrule out, drill the lead at numerous places (swiss cheese) and then pry out. Behind that you'll find the Oakum rope which can be pried out. (Careful not to crack the bell:-( Then put a donut in.

In this case, it may be less risky to remove the CO plug. Don't try to wrench it out if it seems stuck. Use a very sharp cold chisel and chop the center section out. Then you can weaken it and remove. Screw in a 6 X 4 reducing bushing. Then screw in a PVC 4" male adapter followed by your 4 X 2 WYE with a 4" CO plug in the end. (If it's essential to have a full-size 6" CO, hunt around and see if a 6" adapter is available.)

(You may want to measure the CO plug threads to be sure they are 6" pipe size.)

I would plan on a 2" CO TEE fitting somewhere in the 2" drain in the event of stoppages.

Jim

[Speedy Jim]

P.S. Be sure to provide a vent for the kitchen sink trap... Jim

[Paul Riddle]

Jim,

Thanks very much for the insight. I agree that adapting to the cleanout threads sounds like the safer method. If I were to screw up and crack the bell, I'd have a much bigger and messier job on my hands. What kind of thread sealant would you recommend for joining the PVC to the brass ferrule?

I'll be sure to do this, as well as providing for venting. The sink already has its own vent stack. The original drain went to an ancient, homebrew grease trap/holding tank/drywell contraption. The old pipe has failed somewhere underground, and rather than going to the expense of excavating and replacing the line (parts of which are underneath a concrete pool deck) I've decided to abandon it and reroute the kitchen sink to the septic system. Conveniently, the pipe I'd like to tie into is only about 8 feet from the sink.

Paul

[Speedy Jim]

They will both be std pipe threads and you can use Teflon tape or pipe dope. In this app, I like the tape (hevi-duty variety).