How to repair mouldy sealant around your kitchen sink

I have a top mount kitchen sink that sits on a solid surface countertop. After a while, the white sealant around the edges of the sink will turn black and mouldy.

This makes the kitchen look bad, and may also cause water to leak through the gaps, and damage the kitchen cabinets underneath.

But, with a few simple steps, it’s easy to reseal your kitchen sink. Here are the steps:

Top-mounted kitchen sink
Top-mounted kitchen sink

STEP 1: Equipment

It shouldn’t cost you more than RM30 to get everything you need.

Sealant gun
Sealant gun

A sealant or caulk gun (RM5.50). The standard tube of sealant will fit nicely in this gun.

White silicone sealant
White silicone sealant

White silicone sealant (RM5.80). It usually comes in white, clear, and grey colours. I prefer the white. Make sure you don’t accidentally buy filler grout, which is a different material used to fill cracks in the wall.

Pen knife
Pen knife

A pen knife (RM1.80) for scraping away the old mouldy sealant.

Spray bottle
Spray bottle

A spray bottle filled with some soapy water (RM2.68). Soapy water prevents the new sealant from sticking everywhere, so it’s easier to wipe away the excess sealant after application.

Ice cream sticks

Ice cream sticks (RM0.89). I used these to wipe away the excess sealant since the rounded shape gives the sealant a nice curved edge. If you don’t want to buy this, you can always use your soapy finger to wipe.

STEP 2: Scrape away the old sealant

With the pen knife, carefully scrape away the old sealant. The old sealant is very rubbery, so it’s hard to scrape. Instead, what you should do is carefully cut along the top and bottom edge of the sealant, dig it out so you can grab it with your fingers, then pull the entire strip out gently.

Make cuts in the old sealant
Make cuts in the old sealant
Dig out the mouldy sealant
Dig out the mouldy sealant
Removing the old sealant
Pull out the old sealant

STEP 3: Make the area clean and dry

Sealant won’t stick to dusty, soapy or oily surfaces, so make sure you sweep away the old bits of sealant, then wipe and dry the area.

Clean up the debris
Clean up the debris

STEP 4: Prepare the sealant and sealant gun

The tube of sealant should come with an applicator tip. Cut the applicator tip at a 45 degree angle. This will allow you to squeeze the sealant deep into the gaps later on. Then, cut the opening of the tube of sealant and screw the applicator tip on. Finally, load it into the sealant gun.

Cut the applicator tip at 45 degree angle
Cut the applicator tip at 45 degree angle
Cut the opening of the sealant tube
Cut the opening of the sealant tube
Screw on the applicator tip
Screw on the applicator tip
Press the thumb piece on the sealant gun to slide the plunger back
Press the thumb piece on the sealant gun to slide the plunger back
Load the tube and squeeze the trigger a few times until the plunger is seated nicely inside the tube and ready to push the sealant out
Load the tube and squeeze the trigger a few times until the plunger is seated nicely inside the tube and ready to push the sealant out

STEP 5: Apply

Gently squeezing the plunger, apply an even bead of sealant along one edge. Don’t worry if you squeeze too much, since you will wipe it away later.

Applying the sealant around the edge of the sink
Applying the sealant around the edge of the sink

STEP 6: Wipe away excess sealant

Use an ice cream stick to wipe away the excess sealant. The rounded edge of the ice cream stick is great to ensure a nice curved edge.

Spray some soapy water on the ice cream stick and along the newly-sealed edge
Spray some soapy water on the ice cream stick and along the newly-sealed edge
Remove excess sealant using the ice cream stick, and wipe it away on a kitchen towel or rag. Drag it at a slight angle so that you are "pressing" as much sealant into the gap as possible.
Remove excess sealant using the ice cream stick, and wipe it away on a kitchen towel or rag. Drag it at a slight angle so that you are “pressing” as much sealant into the gap as possible.

STEP 7: Repeat for all edges

Repeat the process of sealing up all sides of the kitchen sink, and wiping away to excess. Pay attention to the corners as you will need to have a steady hand to follow the curve of the sink.

STEP 8: Leave to dry

The sealant needs to cure for at least 8 hours (24 hours is even better). At this time, it will emit chemical fumes, so you need to keep the area well ventilated.

Leave sealant to cure for 8 hours minimum
Leave sealant to cure for 8 hours minimum

A nice even edge on all sides!

That’s all you need to do! And as a bonus, after resealing one kitchen sink, there should be more than half a tube of sealant remaining for you to tackle other areas.

Can’t be bothered to DIY?

If your time is needed elsewhere, it’s better to hire a handyman at Recommend.my to do this job for you. Make a list of all the little tasks you need done around the house (e.g. hanging a shelf, patching a wall, resealing the shower partition) and let our handyman do it all at once.

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