Connecting PVC to iron elbow in concrete

[Bilbo6209]

Hey all,

I was installing a new kitchen sink last night and went to disconnect the PVC stub connected to the steel service pipe coming from inside the wall, and the steel pipe broke at the threads in the wall (iron had rusted through due to crud build up in the pipe) without pulling cabinets off the wall there is no way to get a wrench on the pipe or 45 elbow (I was able to get a wrench on the remains of the threaded pipe and all it did was deform due to the rust eating all the structural integrity out of the pipe). I thought I would start down at the clean out in the basement, threw a wrench on it and the entire pipe basically fell over due to the threads rotting off inside the elbow... The outside diameter of the pipe is just under 2". So I went to home depot and bought a 2" Fernco service weight cast iron hub to 2" school 40 PVC compression donut but obviously that doesn't fit... I wasn't thinking of ID vs OD 2" PVC is 2" ID not OD.

What is going to be my best way to connect, I'm guessing 1 1/2" PVC drain pipe to the cemented in elbow that is just under 2" Id?

 

[Reach4]

What are you planning to connect to in the basement? A sawn-off pipe, or what?

What is going to be my best way to connect, I'm guessing 1 1/2" pvc drain pipe to the cemented in elbow that is just under 2" Id?

Do you mean a pipe just under 2 inch OD? or are you talking about a cast iron hub that is just under 2 inches ID?

How about a photo?

 

[Sponsor]

 

[Terry]

If the pipe is gray, it's galvanized steel. Those can be nipples and threaded pipe. Cast iron pipe is black, and is cut or snapped. Often in old homes the joints are poured lead. Putting a wrench on a pipe with a poured lead joint will often with 1.5" pipe, spin it out of the lead packing.
Perhaps you can post some pictures that are 800 pixels or less here?

 

[Bilbo6209]

Sorry for my confusion guys!

OK here are pics and more info
Yes the pipe is galvanized steel, ID of just over 1 1/2" OD of 1 15/16"

The connection on the floor ISN'T threaded, there is a maybe Bell housing, that connects two pipes together with a ring of what I am guessing is Oakum to seal the joint?

here is the pipe

Its hard to see in the pic, but there is a wider ring in this that is about an inch deep all the way around that was packed with what looked almost like a mix of hair and plumbers putty?

here is the stuff that came out of the ring... Is this Oakum?

Here is a side view of the thing I need to connect a new pipe to.

 

[Reach4]

Its hard to see in the pic, but there is a wider ring in this that is about an inch deep all the way around that was packed with what looked almost like a mix of hair and plumbers putty?

There is probably lead melted into the area above where you pulled out the oakum. You will drill out pieces until you can pry that out. You can find Youtube videos on removing the lead.

Then you will measure for the Fernco donut that you need.

Is this Oakum?

Yes. https://en.wikipedia.org/wiki/Oakum

 

[Terry]

A lead poured joint.

The lead and the Oakum removed.

A rubber Fernco insert. You can get them for 1-1/2" pipe or for 2".
I prefer using the 2" especially for a kitchen sink or washer.

 

[Bilbo6209]

Thank you Terry!!! that was 100% what it was! With 50 years of dust, leaks, etc on the top of the connector I couldnt see any difference, but with a little bit of wire brush it shined right up and I was able to drill it out.

That was a THICK pour of lead, it was about 1.5" thick

The 2" to 2" Fernco adapter I bought at Home Depot went in snug, but not as tight as I would think by reading other posts about the trouble people have installing them... how tight should it be? I inserted the PVC first, then grabbed the pipe and leaned on it (Im 6'1" and 240lbs so my lean isnt that light) and the fernco slid in without a ton of resistance. It seems like it should be tighter but having never done this before I don't know what is too loose and what is good. Is there any need to add anything like plumbers putty between the fernco and housing?

 

[Terry]

They do make several sizes in those. I sometimes pick up a few and use the one that fits the best. It has to do with the cast hub, not the plastic pipe.
I normally soap them up and push them in. 2" isn't that hard a fit.

 

[hj]

There is no way you could insert the PVC and THEN insert the "donut" into the cast iron if you had the correct donut.

https://www.fernco.com/plumbing/donuts-o-rings/multi-tite-pipe-gaskets

 

[Bilbo6209]

There is no way you could insert the PVC and THEN insert the "donut" into the cast iron if you had the correct donut.

hmmm that is the exact method Fernco says to use
https://www.fernco.com/downloads/installation-instructions/fernco-donut-installation

 

[Bilbo6209]

OK so is the consensus I should be installing this the other way? Put the donut into the CI section first and then force the pipe into the donut? (mark the length so I know I have it inserted fully)? Is there any harm doing it the by putting the donut on the PVC first?

how can i test for leaks? If this feeds into my main under the concrete there is no way to plug it up to test if it holds water...

Sorry for all the stupid questions, I have never done this deep of plumbing before... I have done work with PEX (sharkbite), PVC, and sweat in Copper... but transitioning from CI to PVC is new to me