Advice on old Osma soil pipe boss

[Timmy D]

Timmy thanks for this advice, but would you then solvent weld the socket into the boss? Is there any reason I couldn't just solvent weld a 40mm coupler in directly if it's a good fit?
A normal 40mm solvent weld pipe fits fairly snug (with 1 or 2mm wiggle room) so was hoping that's close enough to use a gap filling solvent weld.
Cheers

If the coupling fits, then no need for what I suggest.

You just want to get as good a fit as possible. Heavy bonded solvent weld will only take up so much space.

If the coupling doesn’t fit, rather than do what I’ve said, it might be easier to sand the outside of the coupling. Just giving you options.

If the fitting/boss is pvc, solvent weld will be fine.