Leaking belfast sink waste

[dwalsh1]

As the title says. I've installed a belfast sink over the weekend and the waste just keeps leaking. Firstly I put plumbers mate under the waste and tightened the plastic lock nut. Water is finding its way under the chrome waste (85mm in diameter) and trickles down the thread. After speaking to a pipe fitter at work I used silicone mastic under the waste, tightened the plastic lock nut under the sink and f""" me it still leaks. I'm running out of patience so good advice needed please

 

[lame plumber]

little beggars these, lots of p mate and a bit of subtle tightening required, dont force things.

 

[ShaunCorbs]

little beggars these, lots of p mate and a bit of subtle tightening required, dont force things.

+1 you just have to keep trying and try and get a metal waste with metal nut and use plumbers mate also

 

[dwalsh1]

Rubber washer underneath Yeah?

 

[jonnyswamp]

Have you used sealant on the underside of the sink, as well as the top, between the threads of the waste fitting and the bottom of the sink
If you have a Belfast sink, it will have an internal overflow and water is probably running through the slotted waste and then down between the unsealed threads and the sink
If it's an old London (Butler) type sink, it wont have an overflow as such, the "plug" will be a piece of stainless tube about 2 inches shallower than the top of the sink, making an overflow

 

[gasmanrob]

P mait on top and under push a poly washer up then the nut clean of the excess job done..

 

[dwalsh1]

Have you used sealant on the underside of the sink, as well as the top

I squeezed a little mastic onto the underside of the rubber washer. I'm not that confident the washer is big enough for such a large hole.

 

[plumben]

You need to first remove the waste from the sink completely,
clean up the waste and sink,
Check there isn't a crack in the waste or sink if not
then apply sealant to the top of the waste, push it into the sink so that the sealant pushes out around the waste
Apply sealant to the bottom of the waste underside of the sink,
Add a poly washer then the back nut and tighten up
Then remove the excess sealant

 

[jonnyswamp]

I squeezed a little mastic onto the underside of the rubber washer. I'm not that confident the washer is big enough for such a large hole.

I know that feeling

 

[dwalsh1]

P mait on top and under push a poly washer up then the nut clean of the excess job done..

Sorry to be an idiot. not being a plumber are you saying elbow the rubber washer and use a poly one? if so do screwfix sell them..........cheers

 

[gasmanrob]

Yeah rubber washers tend to be naff even the good ones. When tightening they pinch and miss shape poly washers don't pinch.

You'll find poly washers most places that sell plumbing parts

 

[Best]

As has already been mentioned, a Belfast sink has an internal overflow & therefore has a slot in the waste. You must seal the threads where they come out of the base of the sink. Put a mark at that point & remove the waste fitting & use ptfe tape above & below that spot (about an 1" wide) & that will seal the nut to the waste thread joint. Do keep the slot in the waste directly in line with the sink internal overflow opening or it will block in the future! The waste can be sealed top & bottom with any decent sealant. Bottom washer is better sealed both sides, unless it is a very good quality type.
I used to do these with lead washers on base & putty to seal them. That's the really old way.

 

[ShaunCorbs]

As has already been mentioned, a Belfast sink has an internal overflow & therefore has a slot in the waste. You must seal the threads where they come out of the base of the sink. Put a mark at that point & remove the waste fitting & use ptfe tape above & below that spot (about an 1" wide) & that will seal the nut to the waste thread joint. Do keep the slot in the waste directly in line with the sink internal overflow opening or it will block in the future! The waste can be sealed top & bottom with any decent sealant. Bottom washer is better sealed both sides, unless it is a very good quality type.
I used to do these with lead washers on base & putty to seal them. That's the really old way.

not all belfast sinks have overflows

 

[dwalsh1]

Mine leaks with the plug in suggesting it's not the slots leaking, but it is only a rubber plug so not the best. Mine has a weir over flow. I suppose fitting a normal chrome waste without the slots is a bad idea.

 

[Best]

not all belfast sinks have overflows

I know I have fitted some modern ones that have no overflow, but I think they really should have to be called Belfast sinks only if they have overflow. But guess they are same thing.

 

[Best]

Mine leaks with the plug in suggesting it's not the slots leaking, but it is only a rubber plug so not the best. Mine has a weir over flow. I suppose fitting a normal chrome waste without the slots is a bad idea.

If it has an internal overflow, it needs the slotted version of the waste, or the overflow will fill with rotting food etc & stink. Also safer to have an overflow that works

 

[dwalsh1]

I'll try what best suggested with the ptfe above and below the waste threads with the rubber washer cause I cant get to the plumb centre for poly washers cause it closes at 5. Thanks guys for the replies I'm off to bed.

 

[jonnyswamp]

As has already been mentioned, a Belfast sink has an internal overflow & therefore has a slot in the waste. You must seal the threads where they come out of the base of the sink. Put a mark at that point & remove the waste fitting & use ptfe tape above & below that spot (about an 1" wide) & that will seal the nut to the waste thread joint. Do keep the slot in the waste directly in line with the sink internal overflow opening or it will block in the future! The waste can be sealed top & bottom with any decent sealant. Bottom washer is better sealed both sides, unless it is a very good quality type.
I used to do these with lead washers on base & putty to seal them. That's the really old way.

Lead washers aargh, I was taught the same, bit of boss white on the face of the washer then a mixture of paint and putty to seal it
Glad I never had to go back and renew any of those wastes,used to take me nearly half a shift to fit one
My first boss (in the eighties) was proper old school (masochistic) cut the washers with a worn flathead driver, mix the paint/putty by hand etc
Bumped into him a while back and he still wont use a bender, prefers springs. But he had finally invested in a battery drill/driver to replace his pump yankee

 

[jonnyswamp]

not all belfast sinks have overflows

I think the ones with built in overflows were called Belfasts and the ones without Londons or Butlers, as per my earlier post. Though I could have it ar*e backwards

 

[ShaunCorbs]

Lead washers aargh, I was taught the same, bit of boss white on the face of the washer then a mixture of paint and putty to seal it
Glad I never had to go back and renew any of those wastes,used to take me nearly half a shift to fit one
My first boss (in the eighties) was proper old school (masochistic) cut the washers with a worn flathead driver, mix the paint/putty by hand etc
Bumped into him a while back and he still wont use a bender, prefers springs. But he had finally invested in a battery drill/driver to replace his pump yankee

still got the old brace drill (the real old one with the leather bit for your shoulder)

 

[gassafe]

Belfast sink wastes are a nightmare... Only ever did one leaking one, plenty of silicone & told them not to use sink for 24 hours worked a treat, defs use the poly washer tho... Rubber ones are hopeless!

 

[Best]

Lead washers aargh, I was taught the same, bit of boss white on the face of the washer then a mixture of paint and putty to seal it
Glad I never had to go back and renew any of those wastes,used to take me nearly half a shift to fit one
My first boss (in the eighties) was proper old school (masochistic) cut the washers with a worn flathead driver, mix the paint/putty by hand etc
Bumped into him a while back and he still wont use a bender, prefers springs. But he had finally invested in a battery drill/driver to replace his pump yankee

Lol! That's basically same as I had to do, - scratch a circle on the lead around the waste threads, cut the hole in the lead with a flat screwdriver & a hammer on top of a piece of flat wood, then boss white on lead & putty both sides of waste. Tighten it all up and remove excess putty for next job. Victorian but, Lasted forever.