Undermount Kitchen Sink Silicone Mouldy

[Madrab]

There are a few ways that these sinks are secured but most should use echanical fixings. I use threaded rawl sockets that are resin'd into holes that have been drilled into the underside of the stone/marble/granite - the same stuff that HD wall anchors use. There are washers with holes in them and a captive threaded bolt, that's then resined onto to the underside of the worktop, it has a bar that locks onto that with a wingnut.
Then there are washers and S/S wingnuts, S/S threaded washers or a bar and nut that locks onto a threaded bar that's glued into a drilled hole, they then lock the sink into place. There are a few different methods

All use silicone sealant/adhesive to seal them up though.

If they don't use something to secure the sink into place then as far as I'm concerned it's not been installed properly and as suggested it's just a matter of time before it falls down.

 

[emmaamme]

Is that something a plumber could do now ie drill holes to fit the bolts (it's a silestone quartz worktop) or would it be too tricky?

 

[Burnerman]

I would say the risks of breakage would be pretty high to retrofit these clamps.....easy enough with the worktop inverted on a flat solid surface but from underneath, with a hammer drill
Timber laths fixed from below using the cupboard sides to hold a bearer worked well enough for me.
Panic ye not though, it aint fallen down yet
John

 

[Madrab]

If you use a 6mm dry corer, or a porcelain tile drill on slow, no hammer then yeah, easy enough to do, it's a touch feely job and it would be a cramped retrofit, easy to make mistakes.
Easier to retrofit the other ones with the basket washers as they just epoxy into place. As long as they are glued properly, spirit clean the surface, 2 lots of resin one on each, let it go tacky, press on, smooth the adhesive out and support for 24hrs before tightening. To support the sink they don't need to be super tight, just nipped up as they work hand in hand with the silicone adhesive.

 

[emmaamme]

I saw these on Amazon today - they look really good. No idea why installers don't use them in the 1st place. Is there a particular glue you would recommend to stick them on with?

 

[Madrab]

Did you mean to post a picture, as there isn't one??

A good quality 2 pack epoxy, Araldite or similar would do the job, just follow the instructions closely.

 

[emmaamme]

Sorry - meant the brackets you posted (your 2nd picture). Look a lot easier than ones that need a hole drilled

 

[emmaamme]

Wee update - bit the bullet & scraped out old silicone & resealed today (took me hours!) Used my best buy of late - a fugee kit which I can't recommend highly enough. What a great finish it gives. Ignore the messy sink - full of old silicone. Thanks for all the advice. Much appreciated.

 

[polesapart]

Well done - that looks tidy.

 

[emmaamme]

Thanks - fair chuffed with myself. Now just got to try & keep it white!