Foam washer or plumbers putty?

[shd1970]

So as well as other plumbing activities, I’m currently doing I’m just fitting a sink in the garage so I can bath the dog

The sink waste comes with a foam washer to seal underneath where the trap meets the sink

I just wondered what peoples view was with regards to using the foam washer, plumbers putty or both the foam washer with some plumbers putty also ?

I know some do suggest sealant however I have seen a lot of plumbers Don’t favour this due to the time it takes to remove so favour the putty instead

TIA

 

[denso13]

What kind of sink?

 

[shd1970]

What kind of sink?

Stainless steel @denso13

 

[Alec_t]

The foam washer should seal ok. Even if the seal is not 100%, the water leakage would be a lot less than the water your dog shakes off trying to dry itself.

 

[denso13]

As above, just use the supplied washers, normally foam on top and rubber below. No need for sealant.

 

[oldbuffer]

1. Broadly, as above. Foam washer between upper side of sink and underside of waste flange, black rubber washer below sink.
2. If it leaks:
2.1 Remove and discard foam washer.
2.2 Roll a "sausage" 6mm thick from Plumber's Mait.
2.3 Wrap sausage around underside of flange.
2.4 Screw waste fitting in and tighten completely.
2.5 Remove excess Mait from top side of sink anround waste flange. Wooden / plastic scraper, white spirit if necessary.
2.6 Fit black washer to waste under sink and screw up back nut.

 

[dilalio]

For a sink... The supplied foam washer.
For a basin.... Plumber's mait every time for me.

 

[johnny2007]

Am I wrong in thinking that with a slotted waste perfectly sealing the top is not that important?
After all, water goes through the slots in the waste...

 

[shd1970]

The foam washer should seal ok. Even if the seal is not 100%, the water leakage would be a lot less than the water your dog shakes off trying to dry itself.

thanks (I think !)

 

[shd1970]

1. Broadly, as above. Foam washer between upper side of sink and underside of waste flange, black rubber washer below sink.
2. If it leaks:
2.1 Remove and discard foam washer.
2.2 Roll a "sausage" 6mm thick from Plumber's Mait.
2.3 Wrap sausage around underside of flange.
2.4 Screw waste fitting in and tighten completely.
2.5 Remove excess Mait from top side of sink anround waste flange. Wooden / plastic scraper, white spirit if necessary.
2.6 Fit black washer to waste under sink and screw up back nut.

For a sink... The supplied foam washer.
For a basin.... Plumber's mait every time for me.

Thanks @oldbuffer @dilalio
I’ll try the mait I think as the foam washer is pretty dreadful

 

[Justin Passing]

It depends on the foam. If it's thin and insubstantial then Silicone. Plumbers Mait is very variable, and goes hard over time.
Silicone is easy enough to get off with a Stanley knife blade. It also stops things twisting and coming undone, though I'm not saying put it on threads. Only ever use Dow Corning 785+ anti-mould.
There's something in the FAQs about why basin seals leak by design...
Here

For a silicone sealant. Fernox LS-X would be good there because you will get it on the threads. It's NOT strong so you can still undo things once it's set.
That shows the slotted-waste issue. too.
If there's a "let by" at the waste flange, your basin or sink empties past the plug.

 

[Madrab]

Am I wrong in thinking that with a slotted waste perfectly sealing the top is not that important?
After all, water goes through the slots in the waste...

Either slotted or non slotted as the seal would always be @ the lowest point underneath. Think about a slotted waste in reverse, when the water is draining down the waste it could always run out of the slots, so the lowest seal @ the big nut needs to be watertight. The seal in the basin stops the water from running away when the waste is closed.

Mait is a long proven medium to seal stuff up but I avoid it specifically for the next person coming along. It's really is icky icky goo and once it's on stuff is a nightmare to clean off. Lots of other 'cleaner' solutions these days for me.

 

[aveatry]

I dump the rubbish washers and use Plumbers gold silicone and one of these basin mates. Silicone above and below all washers.
I consider the supplied washers the same as when you buy a big cabinet and the supplied rawlplugs and screws are way too small for the job.
https://www.screwfix.com/p/thomas-d...UCF1gumzfpd-kXdaFnRTrqaZi8j8yuDxoCgmEQAvD_BwE

 

[denso13]

There's something in the FAQs about why basin seals leak by design...

It's a stainless steel sink, it'll most likely just be a cheap flat waste kit with two washers.

 

[Justin Passing]

There's always an "unless it's IKEA" caveat. Law unto themselves! I think Franke used to suply kits too. I'm a century out of date though.