Cast Iron Fitting: Threaded, Lead and Oakum or ???

This site has provided me a lot of help over the last few years, but now I need some specific advice. I hope you guys can help me out...

I am about to tear into some 1926 plumbing to replace an old drum trap on a bathtub. Lead pipe ties the drum trap to a cast iron t-fitting, but I can't figure out how the joint is made at the tee, and before cutting out the lead pipe I'd like to have a plan to transition to new PVC. The image below shows the joint, and it appears to be lead to brass, then all soldered into the cast iron hub. Could this be a threaded brass fitting into the cast iron, or is it a lead and oakum joint? Or is it some Frankenstein creation? There was some previous remodel work done where they tied into the old cast iron with a threaded PVC fitting, but it appears that it was at an old cleanout (second image).

Bottom line is, what is the best way to approach tying PVC into this cast iron tee? It's all in about a 16" crawl space, and replacing the tee doesn't seem like a very easy option. Any advice or insight would be appreciated.

-Bryan




Previous remodel:

I think, but am not sure, that there's a brass stub leaded into the hub, then the lead pipe is sweated onto that brass. If so, then you'd remove all the lead, then use a rubber donut (made by Fernco among others) inside the cleaned out hub with a piece of PVC jammed into the middle of the donut. It is crucial to get the proper sized donut so there's enough pressure on it, but not so much that you can't get it inserted. They come in small increments to match the hub.

Thank you for the advice. If it's a standard joint it shouldn't be much of a problem. I'll have a threaded fitting and a donut ready. The picture was taken blind through an access panel, so I haven't been able to get access to inspect the hub up close. Before I make the long, painful trip through the crawl space and over some rat skeletons, I want to make sure I have everything I need for the job.

Your first pic is wiped lead joint and you can cut it out.
Your cast iron look okay.
BTW its the live one I would worry about

The hassle is, the hub may be a variety of sizes - there is no strict standard. Often, the stuff available in on area is one of two sizes 'normal' and extra heavy.

That be a brass caulking ferrul which transitions from C.I. to Lead pipe. You can remove all of it from the C.I. bell using a combination of a 1/4" chisel and a hammer. Go easy, don't chip the cast. If you have a sawzall you can chop the lead off real close to the C.I. and then go with the sawzall, inside the bell, paralel and make a couple of cuts through the ferrul and lead. Again, don't cut the C.I.

So I made the trip through the crawl space to the fitting and was able to measure the ID of the hub, only to find out that the tee is XH CI, so the service weight donut I bought is too small. Good thing I measured before I cut. I'm assuming XH donuts are only available at a specialty plumber's supply shop, and not at the big-box stores, so are there any other options? Is it a bad idea to keep the brass ferrul and attach with a no-hub coupling?

Assuming I do find the correct donut, will it be possible to twist the brass ferrul out of the hub? There isnt enough room to get a sawzall in there to cut it out.

Again, thank you everyone for the help.

You'd probably have to search for the proper nohub fitting, too, as the OD of the brass ferrule is not the same as the OD of say PVC. And, you'd have to get it clean and smooth enough to make a seal - might be a pain with the leaded joints involved.

A leaded fitting has oakum jammed into the joint, then liquid lead is poured on top of it, then the whole thing is again rammed tight (not the true plumbing technical terms here). Note, doing one on the horizontal takes some special skills!

To take it out, you either melt the lead out, or drill out enough (can you say swiss cheese?) so you can then work the pipe back and forth to pull the whole mess out of there. There may be other methods, but those are the two I know of.

here is what you do,cut the lead about 4 inches from the hub,there will be a brass ferrule sticking out of hub.get a torch and heat ferrule,wipe it clean with a scratch pad.you should have about 2inches of brass sticking out of hub.get a no hub coupling and repipe.

In 1926 cast iron pipe had few standards other than the o.d. and i.d. Your hub could fit a rubber donut or not, or it could have "ridges" where the two pieces of the mold fit together. They would not have affected a lead joint but would make it impossible to seal a donut into it.