Silicone question

Is Silicone mastic the same thing as silicone grease?
I've got a slight leak from where the stainless steel plug
hole insert fits into the recess in the plastic sink. The
big plastic nut is tight and the rubber washer is in place
but when the sink is full of water a small leak occurs
dripping below the sink.
Should I use silicone mastic / grease to seat the metal
plug hole into the sink recess?
I'm at the bottom end of the plumbing learning curve - so
still be bit wet behind the ears :-)
Reply to
David in Normandy
I presume what you'd describe as silicone mastic is what's perhaps more normally known as silicone sealant - that sets solidly (well, rubbery) whereas silicone grease is, well, grease - ie it doesn't go off, it just stays at that consistency. It doesn't attack rubber seals like o-rings which makes it good for plumbing use. Another type of gunk is plumber's mait, which is a gunky sealant typically used for toilets or sinks; and doesn't set either, but is not grease-based. I don't go fot it at all myself.
Personally in your scenario I'd dismantle the plug/drain, clean and dry everything then reassemble with a smear of silicone sealant over the rubber seal.
David
Reply to
Lobster
1) Silicone Sealant/Mastic is not the same as Sil. grease the former sets into Sil. Rubber.
2) The leak you have is probably around the threads on the big nut? If so: then put a little PTFE tape on the threads where the nuts will end up before tightening the big nut.
3) Silicone sealant is mark of a bodge, when I see it I know to expect further trouble.
4) There might have been a need put something like plumbers' mait between the waste and the top of the sink.
5) If you really need to use an adhesive the a multi-resin compound like CT1 (aka FT101 from s/fix) is more friendly as it works on wet fittings.
Reply to
Ed Sirett
No. Mastic (or sealant) sets to form a rubber like seal, the grease stays greasy.
Both may work, but sealant will do the more permanent job. A small tube of Fernox LS-X would do nicely as well - this is a sealant type material that is designed for fixing leaks.
Must have you head under the sink then!
Reply to
John Rumm
Although others have recommended the use of silicone sealant in this application, IMO it's not ideal. Silicone sealant doesn't perform well when permanently immersed in water.
A better alternative is Evo Stick Nail and Seal which is a high-performance polymer sealant designed to set under water and which performs well in applications where it is immersed for long periods. Ensure that you clean all the parts well before using the sealant.
I find the best results are obtained by aseembling the parts and tightening the nut partially then allowing the sealant to begin to cure. Then tighten fully and trim away the excess sealant.
Reply to
Steve Firth
In article , Lobster writes
I agree, I think the seal needs to be before the threads (on waste) in all cases but Ed is the guy who does this every day (well, ish).
Reply to
fred
No!
Yes. (mastic that is)
Holds aquariums together fine :)))
cheers, Pete.
Reply to
Pete C
In message , Pete C writes
I was just thinking that
My aquarium contains, what, 1/3 ton of water ?
It's held together with silicone, and has been for at least the past 5 years
Reply to
geoff
IMO? IMHO? Well, what else would we expect from Steve!
That's why it can't possibly work for aquaria then!?
Ah, so polymers are different to silicones?
Reply to
Andy Dingley
It's my opinion, and I wrote what I meant.
Did I say such a thing? No.
Let's put back the text you snipped:
Now don't you look stupid for your silly edit?
Perhaps you could comment on why Nail and Seal is, in your justifiably humble opinion inferior to silicone in this application?
Reply to
Steve Firth
///
After a goodly few failures at getting this type of drain outlet to stay leak free, I took stock & advice from this group.
What now works (for me) is to bed the steel body of the outlet into the sink using a silicone mastic (a transparent one described as 'sanitary sealant' should be OK) then on the underside fill/seal any gap with the sealant put on a plastic nylon plumbing washer then screw the nut on. Take car with plastic nuts as overtightening can cause them to break.
Wipe the away excess mastic with paper tissue. Then wrap PTFE tape on the steel thread and screw the waste pipe coupling on.
Allow the mastic to set to a rubbery flexible state (depends on mastic brand/type, but 20 mins or preferably overnight) before using. Do not disturb during the setting process.
BTW thoroughly clean off any remains from any previous plughole fixing. You need to bed the new one on an as-new surface.
HTH
Reply to
jim
The ability to happily restrain and seal glass under a load of a ton of water for many years is a strange interpretation of "not performing well".
Reply to
Andy Dingley
Silicone is not permitted for use below the waterline on ships because of its poor performance. They are not recommended or the construction of aquariums of greater than five gallons capacity[1], nor for use as adhesives in such applications and the silicone must be allowed to cure for at least five days before contact with water. MS polymer sealants such as Nail and Seal are perfectly acceptable in such applications and cure while immersed in either fresh or salt water.
Hence although silicone sealants may be used for the construction of (small) aquariums they are barely suitable for such use, and are IMO unsuitable for use in sealing sanitary fittings to be used underwater unless the user can manage to leave the fittings dry over a five day period.
Maybe you should stick to something you know about, if you're attempting to score cheap points off me?
----------------- [1] Here's a typical quote from a manufacturer of silicone sealant:
Can I use silicone sealants underwater?
GE Silicones does not manufacture silicone sealants for use in underwater applications. Examples of underwater applications are: swimming pools, saunas, hot tubs, spas, Jacuzzis, boats or any other marine vehicles. The only exceptions are the following sealants, which may be used for sealing small (i.e., 5 gallons or less) aquariums:
GE012 -- 10.3 fl. oz. cartridge -- Clear Silicone Rubber Sealant. GE361 -- 2.8 fl. oz. squeeze tube -- Clear Household Glue & Seal
Application must be as follows:
Glass to glass use only Sealant must cure for a minimum of five days before exposure to water The products listed above should be used as sealants only, not as structural adhesives.
NOTE: Use of other grades of silicone in an aquarium or failure to let the sealant cure for the proper amount of time could cause harm to fish or other life forms in the aquarium.
The quote came from:
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but the site has since been reorganised by GE. A reference to the page can be found here:
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there's this:
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- Can I use silicone sealants under water? Silicone is a good waterproof material, but when used under water care must be taken to protect for 5 days after installation from direct contact with water.
Reply to
Steve Firth
In message , Steve Firth writes > >> >> > > >Silicone sealant doesn't perform well >> > > > when permanently immersed in water. >> > >> > > That's why it can't possibly work for aquaria then!? >> > >> > Did I say such a thing? No. >> >> The ability to happily restrain and seal glass under a load of a ton >> of water for many years is a strange interpretation of "not performing >> well". > > >Maybe you should stick to something you know about, if you're attempting >to score cheap points off me? > >----------------- >[1] Here's a typical quote from a manufacturer of silicone sealant: > >Can I use silicone sealants underwater? > >GE Silicones does not manufacture silicone sealants for use in >underwater applications. >The quote came from:
formatting link
but the site >has since been reorganised by GE. A reference to the page can be found >here: > >
formatting link
there's this: > >
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've morphed into Drivel, haven't you ...
Reply to
geoff
Uh huh, I note you ignored "The products listed above should be used as sealants only, not as structural adhesives."
Better to have kept quiet, than to remove all doubt, Mr Dingley.
Reply to
Steve Firth

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