How to Caulk a Kitchen Sink

Caulk is a sealant that is most commonly used in kitchens and bathrooms. It’s applied along the joints where your sink meets your countertop to stop water and gunk from getting into the gaps.

It’s essential to have it, and it needs to be applied correctly. If water gets into these crevices, it can lead to some quite serious issues, such as mold, mildew, and even creepy crawlies, yuk!

Caulk isn’t designed to last forever, unfortunately, and over time it will erode, and gaps and tears will appear. When this happens, don’t fret, it’s an easy enough job to do, and it requires next to no technical know-how.

It’s a job that you can most definitely do yourself at home, with just a few tips and pointers in the right direction.

Note: this process will vary depending on the type of sink you own, so please keep that in mind.

Step 1

You’re going to need a razor blade or a very sharp knife to cut away the old caulk sealant and glue from your kitchen sink.

You should hold the blade away from you at all times and laterally to the edge of the sink. This is so you can cut away the old caulk without nicking or cutting into your countertop as you go.

Take your time with this and don’t rush it. It’s more important to get this step done correctly than quickly.

Countertops are expensive and cut fingers hurt and take time to heal!

Step 2

Now you’re going to need to peel off all that old, gunky, caulk away from your kitchen sink. You probably won’t be able to get it all off with just your blade and by picking at it alone.

If that’s the case, a small solution of warm water and washing up liquid should do the job. Work your way around the sink with a gentle sponge and remove any residue of the old caulk that you see.

At the same time, make sure to remove any dirt, grease, mold, or mildew you come across too. Now run a dry cloth around the sink before moving on to the next step.

Step 3

For this next step, you’re going to need some isopropyl alcohol, otherwise known as rubbing alcohol. You won’t be able to pick this up from the local liquor store, I’m afraid, but the local hardware store should have plenty in stock.

If you’re unable to find rubbing alcohol or can’t use it for whatever reason, hand sanitizer, with alcohol, would be an acceptable alternative, as would white vinegar or bleach. They should all get the job done.

Now take a slightly damp cloth and clean within the joints with the rubbing alcohol (or alt.). Make sure you get into all of the nooks and crannies. We need a thoroughly clean surface to apply our caulk too later on.

Once done, rinse your sink down with cold water and allow it to dry thoroughly before moving on.

Step 4

For this next step, you will need some masking tape. This is going to help you to keep your countertop clean from caulk when you apply it later on.

Take a piece of tape and stick a strip of it on both sides of the caulk line, all around the sink. Make sure you’ve covered the entire area and that it’s neat, tidy, and, most importantly, straight.

When you’re sure you’ve got it in the right place, and you’re happy with it, it’s time to commit! Run your fingers around the tape and press it down firmly.

Step 5

Next, you will need to take your tube of caulk and load it into a sealing gun. These are very easy to pick up from hardware stores, and many superstores stock them too in their home improvement, DIY, sections.

Once loaded, you’re going to need to make sure that the nozzle is the correct size for your kitchen sink joints. Take a blade and cut the nozzle at 45 degrees, more or less. Now, test it out on a piece of paper, does it look about right? If not, keep trimming until you get the desired output.

Step 6

Place your nozzle in the joint and apply light pressure to the trigger of the gun, slowly making your way around the sink, filling in the gap with the caulk as you go.

Take your time with this and don’t worry if it’s looking a little messy, remember, that’s what the masking tape is there for, it’s okay. We will take care of that in the next couple of steps.

Step 7

Now that you’ve filled in the joints with the caulk take a moment to ensure that it’s consistent. Make sure that you’ve filled it all the way around and that there aren’t any gaps or holes in the caulk.

If you’re happy with your work, take your finger and run it along to the top of caulk, all around the sink, to smooth it out and give it that professional look.

Step 8

Remove the masking tape before the caulk has time to settle and dry. Don’t forget this part; if it dries and gets stuck, you may have to start this whole process again. Lift it gently and at a right angle to ensure it comes off in one piece and doesn’t bring any of the caulk with it.

Step 9

Now wipe away any of the excess caulk sealant with a warm damp cloth, while it’s still setting. If it dries, it’s not the end of the world, but it will require a little more work to clean it off, with a brillo pad or scraper, but it’s best to get it while it’s still fresh.

Step 10

That’s it. You’ve finished, you have successfully replaced the caulk and sealed your sink up for the next few years: goodbye mold, goodbye mildew, and goodbye washing up. Yes, really, no washing up, no liquids or moisture anywhere near the newly sealed joints for the next sixty to seventy-two hours.

For more information on the drying time of your caulk, you can check the labels, but you are usually looking at three to four days before it’s thoroughly dried.

Also, if you are thinking of replacing your kitchen sink, please check out my buyers guide here: https://www.mrkitchenfaucets.com/best-kitchen-sinks/.

What Is The Difference Between Caulk and Sealant?

Caulk and sealant are often used interchangeably, and for the most part, that is fair.  Each is used to fill gaps between building materials.  With respect to kitchen sinks, this is an important installation and maintenance step to prevent water seepage into spaces where it could cause harm.

They are both applied in the same manner, either by using a caulking gun or your finger from a squeezable tube.  Their use depends on the environment in which they will be used.  Caulk is usually an acrylic, while sealant is a silicone.

Caulks are more rigid than sealants, dry out over time, and will crack in environments subject to wide temperature swings.  Sealants are flexible and handle temperature swings well without cracking. 

Acrylic caulks can be painted and are easily cleaned when you smear them during application.  Silicone sealants are not paintable, require a solvent to clean them up, and emit fumes when applied.

Which Is Best for Your Kitchen Sink – Caulk or Sealant?

Temperature swings and moisture define the environment of a kitchen.  Water seeping between your sink and your laminate or wood counter, or the wood framing that supports the sink, will eventually cause harm. 

You can anticipate, then, that a silicone sealant will serve you better with your sink installation.  In another post, we talked about sealing a drop-in, or top-mount, sink, and you will find it here.

What is The Caulk for an Undermount Sink Installation?

The simple answer is a sealant.

Many brands, in fact, recommend a 100% silicone sealant be used in your undermount sink installation.  Moen, one such manufacturer of sinks and fixtures, is one of them.

Best Caulk For Kitchen Sinks