How to replacing an undermount ceramic sink?

[Bonnings]

G'day all, I dropped a pot onto my under-mount ceramic kitchen sink and it is now cracked through and leaking. I wish to replace the sink like for like. The current sink is presently glued up against the underside of the kitchen countertop and as far as I can tell, the glue is the only thing holding it up, which has worked just fine. Question is, can the sink be easily be replaced? In other words, can the sink be removed, can the glue be cleaned off the underside of the countertop and a new sink be inserted and glued back on the same way? Cheers

Glue

Glue

Glue

Undermount glue and pipe

hairline cracks across RHS of sink

Pipe

Pipes

Contextual view

[MitchellMc]

Welcome to the Bunnings Workshop community @Bonnings. It's sensational to have you join us, and many thanks for your question about replacing a sink.

There are no issues with replacing the sink, and the method you've described is how it would be done. The most complicated part will likely be tracking down a sink that suits your cutout in the bench. If you know the brand of the sink, it will make things much simpler to purchase a replacement. If you don't and can let me know the dimensions of the cutout and sink, then I can take a look to see if I can find something that will suit.

Please let me know if you have any questions.

Mitchell
 

[Bonnings]

Hey Mitchell

Thank you for your reply, it's much appreciated.

I can buy the sink - it is still a current stock in the shop.

I just don't know how to remove the sink, what product to clean off the glue, and what glue to use to stick a new sink back on.

Any products in Bunnings that can help?

Cheers

[JacobZ · Accepted solution]

Hi @Bonnings,

You'll need to start by removing the U-bend underneath the sink to allow its removal. This can be done by rotating the collars at each end of the U-bend. If they are stuck tight, you can use a Trojan 350mm Pipe Wrench to increase your leverage.

Once the U-bend is disconnected, you'll need to cut out the silicone using a sharp utility knife to break the connection. Please ensure you wear gloves, long sleeves and eye protection to prevent any unnecessary lacerations.

When the silicone has been cut, you should be able to remove the sink and then start cleaning up any residual silicone that is left in place. You should be able to remove much of the silicone with your utility knife or a paint scraper, however, if it is particularly stubborn, this Selleys Silicone Remover would certainly help.

Once the surface has been cleaned up, you should check the sink manufacturer's instructions to see if they have a recommended silicone or adhesive for installation. If they do not specify, then Sikaflex 11FC is usually a good choice.

I'd suggest having a look at how @martincv has held his sink in place while the adhesive sets in How to affix a replacement undermount basin. This can be done with some scrap timber, a threaded rod and wing nuts.

If you have any concerns with the process, it may be worth contacting a plumber for assistance.

Let me know if you have any further questions.

Jacob

[Bonnings]

Thank you so much for the clear instructions!