Strange sink drain issue

[John Carlson]

A few weeks ago our bathroom sink drain started gurgling. It happens about 30-90 seconds after you stop running the water at the sink. It wasn't happening previously and the house was built in the mid 1960s. The gurgling also seems to be only caused by running water at that sink, flushing the toilet or running the shower doesn't seem to cause it.

Unless a flying squirrel jumped down the roof pipe, I don't think anything has happened to the plumbing vent. Also, the sink has been draining ok, but maybe not as quickly as it used to. We have copper drain pipes and I'm not sure if drain openers like Drano (NaOH) will corrode the copper.

Any ideas? Thanks!

[Dave Balderstone]

Plug the overflow drain (wet your hand and press against it) then run some water and use a plunger. I bet you get a whole buch of evil smelling crud coming up the drain into the sink...

Hair, soap scum etc. Skundge buildup.

If the sink has one of the built-in lever driven plugs, disassemble and remove it. Betcha it's filthy.

Use a drain cleaner, plunge, drain cleaner, plunge. If you still have the problem, disassemble and clean/replace the trap and/or the sink.

djb