Water closet flange - what would you do?

I had/have a rocking toilet. I pulled it and found what you see in the photo except that it had a flange partially soldered to the 4" soil pipe. I easily pulled that off the pipe by hand. The soil pipe is flush with the tile floor.



Short of "call a professional plumber", how would you fix it?

Thanks in advance.
Fearless homeowner.

Bronze or copper toilet flanges are still available, and would be the thing you'd attach to the pipe. What is the old one made or? You'd also want to fill in some so that the bolts could anchor to something. To be able to solder it back on would require a few things - buying or borrowing them if you don't have them might make it cheaper to get a plumber to do it. To get a good soldered connection, first you'd have to clean the outside of the pipe and the inside of the flange very well. Then, you'd need a big enough torch so you could get the pipe and flange hot enough to actually melt the solder (this assumes you know how to solder!). The insides of the pipe look fairly clean. They do make a flange that goes on the inside of the pipe (this might be an option if it is a four-inch pipe, don't consider it if it is 3" ID). This has some gaskets that seal to the inside of the pipe. The flange must be anchored to the floor, though, so again, you may need to fill in some around it so it would hold an anchor.

Thanks for the quick and thorough response Jim. I was looking at a 4" Oatey 42255 165 Cast Iron Flange. I'll assume I need to fill the gap with concrete in order to anchor the flange, but to what height? Will the flange rest at floor level or will the flange rest above tile level. Assuming I don't want to solder, am I on the right path?

Is this an internal mount flange? Only consider one if the ID of the pipe is 4". A toilet flange is designed to sit on top of the finished floor and be anchored through it into the flooring with no gaps beneath it.

How about this? Yes. The inside diameter is 4".