Sealing (westerly) sink: idiot question

[laika]

Forgive my ignorance: I've never owned a house to acquire "domestic" skills.

Water is dripping down the sides of my sink into the cabinet below. If it were a deck fitting or a window I'd take it out and bed it back down with sikaflex. Having watched some youtube videos on domestic sinks people seem to be leaving them in situ, digging out old sealant with a knife, then adding more (clear silicon?) sealant without removing the sink.

How would others go about sealing a leaky sink in their galley?

 

[ex-Gladys]

I've just this winter made a few changes to my Galley and have ditched Silicon sealer because every time I have to get the sink out for whatever reason it's obvious the sealer has been ineffective. This time I'm trying Scapa bedding tape, seems pretty good so far... and hopefully will enable me to remove the sink at will to get to the mess of plumbing underneath the easiest way...

Obviously the question you need to ask yourself is are you sure the water's coming from the bedding of the sink? I've discovered through this piece of work that the leaks are far more likely from the pressurised water system... Don't ask me how I know....

 

[l'escargot]

Trying to reseal it in situ would only be a bodge and a temporary measure - you would be lucky to get all the old sealant out and new silicon won't stick to old silicon. You will end up doing it again and again. Only sure way is to take it out and rebed it.

 

[fergie_mac66]

Ordinary silicone is not v good. Get low mod neutral cure constructional silicone. It's used for making fish tanks so long as the substrate is dustfree and totally dry that will solve the problem,ever seen a fish tank come to pieces..

Low mod has very little smell by the way. If I t smells of vinegar it's the wrong type

Agree with last post best to rebed properly

 

[VicS]

I agree the way to make a 100% effective and lasting job is to remove the sink clean off all the old sealant and refit .

You might consider CT1 or StixAll as an alternative to silicone sealant or Sikaflex. I dont know where you'd buy CT1 but Stixall is available from Toolstation.

They should perform better than silicone and although adhesive sealants not quite as tenacious Sikaflex. If OTOH if a polyurethane sealant like Sikaflex is your preference consider Puraflex PU40, which is also available from Toolstation

Both Stixall and PU40 are made by Everbuild which is part of the Sika group

 

[stuartwineberg]

Geocell is a similar adhesive sealant that will stick and cure in damp conditions although you need to have a surface free of grease. Available in B&Q and in builders merchants. I have pretty much abandoned silicon for the reasons given above

 

[l'escargot]

I agree the way to make a 100% effective and lasting job is to remove the sink clean off all the old sealant and refit .

You might consider CT1 or StixAll as an alternative to silicone sealant or Sikaflex. I dont know where you'd buy CT1 but Stixall is available from Toolstation.

They should perform better than silicone and although adhesive sealants not quite as tenacious Sikaflex. If OTOH if a polyurethane sealant like Sikaflex is your preference consider Puraflex PU40, which is also available from Toolstation

Both Stixall and PU40 are made by Everbuild which is part of the Sika group

I like CT1 for marine use but have to order online as it doesn't seem to be widely available. Recently found "HB42" in the local hardware store though that seems to be a direct equivalent.

 

[laika]

Thanks for the replies. A couple of follow-up questions would be:
- If this were a deck fitting I'd wait for the sealant to cure slightly before cranking it down a bit more to avoid squeezing out all the sealant initially but the sink seems just stuck in (no screws to "crank"). and therefore seems to be just held in by the sealant's adhesive properties. If removing and re-bedding would the norm be to just lay the sink on a bead of sealant and allow it to stick or push it down?
- A lot of people have strong opinions when it comes to deck fitting sealants. Whilst these are all great to know, what would be the "baseline" sealant, i.e. if sikaflex 291 is the "normal" solution for bedding deck fittings, what would be "normal" for a galley sink: not necessarily the most cost effective or longest lasting, just the "norm"? I'm thinking that "clear drying" is a bonus in this application for aesthetic reasons.

 

[prv]

If removing and re-bedding would the norm be to just lay the sink on a bead of sealant and allow it to stick or push it down?

I think I might put the plug in and fill it with water to provide a moderate "clamping" force while it dries.

Pete

 

[Tranona]

Domestic sinks are bedded down on butyl tape - or at least that is how I did mine over 30 years ago and it has never leaked. It came with a shaped gasket and was tightened down onto the work top with screw clamps.

Suggest you take it out, clean it up and use tape. If there are no clamps put some weight in the sink to hold it down.

 

[VicS]

I like CT1 for marine use but have to order online as it doesn't seem to be widely available. Recently found "HB42" in the local hardware store though that seems to be a direct equivalent.

Yes It looks like the same type of material as CT1 and StixAll.