vandelay wrote:

Hello vandelay

v| He's given me a waste which appears to be the right one, but
v| when it's tightened up, it leaks. Water appears to be coming
v| from the union of the sink and the waste underneath, where
v| the plastic bolt is which holds it in place. Before you ask,
v| yes, I've put rubber washers on both sides, and after
v| discovering the leak, I took it apart and put some silicon
v| in to help too. No luck - it's still leaking.

You are using ptfe tape in the threads, aren't you?

If the threads go tight (ie, don't slip) then they're correct. If
water leaks from the threads, you need tape.

As for the assembly through the sink, non-setting plumbers mastic is
usually used to bed the waste on (upper side) before tightening, then
wipe off any excess.

--
Simon Avery, Dartmoor, UK
uk.d-i-y FAQ: http://www.diyfaq.org.uk/