Joining abs into cast iron cleanout

[Kiwinadians]

Greetings from a new user,

I have an early 60s home that I am currently renovating and am replacing the entire main stack and all sanitary plumbing as it is copper and has signs of corrosion.

My house has a main stack, where the upstairs toilet, shower, sink, as well as kitchen sink tie into. It also has a secondary soil stack from the downstairs toilet, which has the downstairs sink, kitchen sink tied into which then vents into the main stack when it reconnects upstairs above the flood level of all fixtures.

This secondary stack is a 1 1/2" copper pipe that runs directly into a cast iron wye with a clean out. After removing the copper, how would I connect a 1 1/2" abs pipe into the cast iron fitting? Is there a rubber bushing, or some product that works for this? Can I use 3" to 1 1/2" abs bushing, and if so, how do you secure it into the cast iron.

Thanks heaps for the help!

 

[Kiwinadians]

I think I may have answered my own question through a deeper web search. Fernco makes a "donut" (Fernco Donut Installation | Fernco - Canada) that seems to be fit for this purpose. Has anyone used this before and can speak to how well it works?

 

[TomFOhio]

You can get abs to cast iron mission couplings

 

[DFBonnett]

I think I may have answered my own question through a deeper web search. Fernco makes a "donut" (Fernco Donut Installation | Fernco - Canada) that seems to be fit for this purpose. Has anyone used this before and can speak to how well it works?

Used donuts to run 2# and 3# PVC into existing 4# cast iron hubs. Fine for 30+ years so far.