Chrome U bend leaks

Is it the joint with the fibre washer thats leaking? If so, a smear of Jointing compound, (Boss White) on the faces of the fibre washer should do it. These fittings are not very tolerant of mis-alignment. Are you sure it is correctly aligned?

I'm sure the real plumbers here will jeer at me for this but I have found Plumbajoint (silicone sealant made by Dow Corning) absolutely invaluable for sealing compression and similar joints which sinply won't stop weeping otherwise. Haven't used Fernox LS-X but it looks similar.

Yes, the joint with the fibre washer. It's lined up as well as I can but no, a little off perfect and with no prospect of a perfect alignment.

The flange that mates with the waste fitting on the bath is screwed into the P-bend part of your waste fitting (otherwise how could they get the big chromed nut onto the fitting?). Unfortunately as you tighten up the nut it tends to unscrew the flanged piece which then leaks no matter what sort of washers etc you use. All you need to do is tighten the flange into the rest of the fitting (IIRC there's a fibre washer that makes that seal) and it'll be hunky-dory.

Been there, done that :-(

I use Fernox LS-X on these types of joint. If you have none, then sanitary silicone will also do. Continue with the washer, though. Coat it both sides with LS-X and reassemble the joint.

Christian.

I won't laugh as Fernox LS-X is invaluable for all sorts of repairs. It has got me out of a few PITA situations, and has given me great peace of mind on the occasional "will it or won't it" compression joint.

But then I'm not a "real" plumber, though I have seen traces of it around "professionally" fitted radiator valves more as a precaution than a necessity I would guess.