Removing galvanized steel pipe from cast

[JDkimes]

I have two instances where some threaded galvanized steel pipe runs runs into some hubbed cast iron. I want to replace the steel portion with ABS but wondering:
1. How do I get that steel out? (Is it really threaded in there as it appears?)

2. How do I go from the hubbed cast iron (in one case a 90 deg-T)to the new ABS? I guess I use a "fernco" type adapter?

 

[Jadnashua]

My guess is that it is leaded in...if you scratch the stuff around the pipe, can you tell?

You'd have to clean the oakum and lead out then use one of the doughnuts or plastic lead to set in a new pipe.

 

[Sponsor]

 

[JDkimes]

What are you referring to with "doughnuts" or "plastic lead"?

I guess the other question is: Should I worry about it? The house is 50yrs old and the steel pipes look ok, but tearing a bathroom apart and have access to them so if I'm to do it now is the time (I guess I'm assuming they're likely to rust out)

 

[Jadnashua]

Fernco makes a special rubber shaped like a doughnut that makes a fiction fit when installing plastic into cast iron fittings.

An alternative to doing a leaded connection (which won't work with a plastic pipe) is a special plastic. I've never used it, but read about it here. It may or may not be a viable alternative, but look into it. The doughnuts are often referred to as a pain to get to seat, but I've not done that either!

 

[JDkimes]

The thing about these steel pipes that where they go into the cast iron they are threaded. Why would they thread them if they were going into a cast iron hub?
So what are all the options to go from an ABS into the cast iron hub?

 

[Casman]

I had galv with threads into cast and I unscrewed the cast and replaced with pvc. I used a threaded pvc fitting with 2 inch pvc and it fit no problem...Did I do this wrong? or am I missing something...

 

[Jadnashua]

If it was threaded, and you replaced it with threaded...all is well.

Trying to remove a threaded connection can be a pain when it is really rusted. If you do get it out, and the threads are still intact, then you can put in a new piece...you might need a lot of pipe dope to make a good seal.

 

[JDkimes]

Good to know. Are there any trick to loosening the thread/pipe? WD-40, heat, cold...
Also, I worry that I'll mess up those cast iron lead/oakum joints if I put too much pressure on trying to unscrew the steel. How tought are they?

 

[Kordts]

Those fittings are tapped for IPS. I usually bang on the hub with a hammer, bang some more, then put a good sized pipewrench on the pipe, apply torque, and start banging, works almost every time. It never hurts to spray penetrating oil first.

 

[Banjopete]

Bringing it back from the dead but new user and I used the search to find this info, and hopefully get some insight from the pros along the lines of this post.

I have removed a wet bar, what remained I quickly capped during demo, to figure out later, and now it's later. I want to remove the Y from the cast iron(?) drain that is heading to the sink drain, and replace it with a straight section of something into a 90 degree back to the existing sink drain (on the right side of the photo:







hopefully my pictures work for everyone, it's my first post so I'm assuming the photo img links work?

Anyways I'm mostly wondering before I embark on this can I just bang/heat the threaded joint and put a wrench on it to unthread the joint? any worries of breaking things? brittle cast? brittle galvanized? things like this? I'd like to diy this unless you guys think this is a terrible idea. thanks

 

[Banjopete]

I have more work to do to tidy up the area but but main job is that cast iron and threaded Y removal, so that's my first job and worry

 

[Terry]

That nipple should unthread from the fitting. Sometimes a little heat on the hub of the fitting and a large wrench.
The large pipe wrench may be all that's needed. By this time, the nipple may need replacing anyway.

If you were removing more fittings, like the cast into the cast hubs, with those I may take a drill and flat blade screwdriver and drill out and pry out the lead there. They make a rubber sleeve that lets you insert a 2" pipe in it's place. The sleeve goes in the hub, and then I taper the end of the pipe, add a little liquid soap and push it in.

 

[Banjopete]

Thanks Terry for the reply, at this point I don't need to expand the scope of the project so it's just removing the threaded Y (fitting?) from the cast column. Just so I'm clear the nipple you are referring to is what I'm calling the whole Y piece? or is it just a male/male threaded connector ahead of the Y fitting (sorry I don't know the correct lingo)?

 

[Banjopete]

I think I answered my own question regarding the nipple. To confirm, from the main drain stack, there is a male/male nipple, threaded into a female y fitting and onwards to my sink drain. So I could try to unthread the whole nipple and fitting and see what gives first, then replace the nipple into the cast main drain stack, and replace my Y fitting with a straight piece of appropriate pipe and make the connection on the other end with rubber/pvc fittings of some kind from the local plumbing supply? Am I crazy or on the right path?

 

[Terry]

Once you remove the threaded nipple, you can thread back in a plastic male adapter and then run the rest in plastic.
ABS or PVC

 

[Banjopete]

Awesome thanks again Terry, I'll follow up with how it went.

 

[Banjopete]

Well great success thanks to your help Terry, I got a wrench on the pipe after cutting it off and it came out without a fuss. The ABS was great to work with and I knocked out two plumbing projects pretty quickly. This fix I was asking about put all my plumbing (save the main toilet drain) back into the wall so everything seems a little better now.