Make it safe
Put a bucket and an old towel under the trap.
All guides
Greg’s field guide
Drains & P-Traps
Clear a stoppage and understand the bend under every sink.
03
First, understand the job.
That curved pipe is not wasted space. A P-trap holds a water seal that keeps sewer gas on the correct side of the house.
Greg’s stop sign: Never mix chemical drain cleaners or open a trap after using one. The liquid sitting there can burn you.
Step by step
Do it in this order.
Find the actual problem
Loosen slip nuts by hand first; use pliers gently only when needed.
Make the repair
Clean the trap and inspect washers for splits or hardening.
Test your work
Reassemble squarely, hand-tighten, then run a full basin of water while checking for drips.
One last check
Dry everything, run the fixture more than once, and look again in ten minutes. A tiny drip now becomes cabinet damage later.