I need to replace the trap under my bath sink. The copper pipe is flush with the wall.Can't solder or add a fitting. The pvc fits somewhat snugly into it.
How can I get a good seal to the pvc trap. Maybe a special glue?

Cut the wall back and expose the copper stub out. Now solder on a slip to female thread adapter and convert to PVC using a PVC slip to male adapter.
Good luck, Tom