leaking toilet cistern from thread flats?

[Quadroclops]

I know this topic has been covered extensively (!) before, but here's a new angle, I think...
I fitted a close coupled cistern with an opella torbeck siphon (internal oveflow with dual pushbutton), & a new bracket + a big solid (not foam)doughnut washer -no leaks at first then the next day a weep on flushing. Tightening bracket didn't help, so I dismantled it again & noticed that there are flats on the pipe threads -I reckon that water passes up these flats & up between the doughnut & the metal bracket/cistern base.
Next step -after reading previous posts- will be to do it again with Plumber's Mait on those threads, I reckon -anyone want to comment?

 

[chrishutt]

Sounds logical, but I'd use silicone sealant myself. Same principle anyway.

 

[Quadroclops]

uh oh... many thanks for this Chris, but did you see what happened last time someone suggested silicone for this? (stir, stir)
I've tried silicone before for watertight sealing on this sort of thing -waited 20 mins for solvent evaporation & re-tightened assemblies before putting into use, & still had leaks, so I'd prefer to use the old stuff -as long as it's all dry before assembly, it's usually ok -mind you, I'm certainly not a time-served man, just a poor boy with a tight wallet!

 

[chrishutt]

Yeah, if you want to start an argument between plumbers, ask them what sort of sealant they use. And if you want it to turn nasty, mention Plumber's Mait. It's like Marmite, you either love it or hate it.