https://picasaweb.google.com/112652995081934659158/MaintenanceStack#5702142593524820034

I just removed a 2" (more like 2.25") brass plug from a cast iron waste line today.
It was recessed in the wall, which made it very difficult to get a wrench on.
But I have never been able to get one to turn; they seem to weld themselves to the cast iron.
I cut them out using a thin circular grinder blade, and a hand-held hacksaw blade.
Once a decent size wedge is cut free, it can be worked with a chisel and pliers to get it out.
The remaining cap will then turn. I don't like the bashing approach; you might just create a crack
In the cast iron, and learn about it the hard way months later.

I plan to replace the old brass plug with an expansion test plug; anybody see a problem with that?

https://picasaweb.google.com/112652995081934659158/MaintenanceStack#5702142593524820034

Hi GISB

An expansion plug may work... may not, too! I'd recommend installing a replacement brass plug... just be sure to use a good quality thread sealant (such as rectorseal #5... available at all home improvement stores), or a plumber's "heat-pruf" grease on the threads, OK? Do not overtighten... ;)

I won't go into details on "bashing out" plugs, but when done right it can really save some hassle/time! I am glad to go into details if anyone asks!

Good luck!

Mark

Hi Guy and Welcome to The Plumbing Page. At AskMeHelpDesk.com. You're responding to a 3 year old dead thread so I gave you one of your own. Look in then upper left hand corner of the first post form the date before you post, Thanks,

Let me add a bit more about breaking out a brass clean out cover. I Take a hammer and break that sucker out in the middle, being careful the pieces don't fall down the opening. If it can't be pulled out take a chisel and break the brass threads loose. You may now either turn or simjply peel the rest of it out.
I'm with Mark on the expansion plug. We use those as test plugs when we're filling the stacks for inspection. You may now replace with another brass cover or go to PVC/ I would wrap the threads with Teflon Tape before installing. Good luck, Tom