I’ve recovered the lost earring from the bathroom sink drain, cleared a clump of hair and cleaned the pipe joints. Now the P-trap is put back together.
This repair is continued from How to Retrieve an Item Dropped Down the Sink Drain – Part 2.
Reassemble the Sink Drain P-Trap
I begin by aligning the sink drain J-bend to the pipes and screwing on the left slip nut. Do not over tighten the slip nut, when snug give it a 1/4 extra turn or so. Note the self-seating gasket formed into the end of the PVC elbow (left side).

The nylon gasket must be slipped down the drain pipe to meet the J-Bend before the slip nut is screwed on.

The nylon gasket is seated in the J-bend:

Turn the slip nut until snug, then give it a 1/4 extra turn or so. Do not over tighten or you could crush the nylon gasket.

Here’s the reassembled P-trap and J-bend.

The the pop-up drain pivot rod and drain stopper are re-installed in Part 4.
Regards,
Bob Jackson