sealant or sealer for undermount sink

[ih]

hi
i have a franke under mount sink with a granite work top. after over 9 years the sealer which was originally put by the work top manufacturer has cracked and water is leaking when sink in use.
1.do i need a sealer or sealant for underneath. (what type please give name)
2. since i will have limited access underneath i intend to apply the same to the sink from top side which should seal better and stop water from leaking .
3. I am assuming the sealant or sealer has to bond steel with granite.

Thanking you in advance for all the help and advise.
ih

 

[crockett]

A decent bathroom silicone sealant will do the job. It will bond most non porous surfaces together.

 

[Kes]

What holds the sink up to the worktop? Is this flexing? There's a lot of weight and pressure put on a sink (just weigh a full bowl of water) so you will need something more substantial than bathroom sealant in my opinion, unless the sink is very positively supported. The joint will not be dry, and won't dry either. The best silicone sealant is Sticks Like Sh*te from a real builder's merchants. Try to get as much gunge out of the join and as much sealant in, and support the sink permanently as best as you can.

 

[ih]

kes thanks very much for the advise and help