How To Caulk A Sink
If you are caulking a sink that is a new installation or re-installation, it is good to seal the gap around it to your counter top to keep water and grime out and glue the sink in place. Water can damage that area raising the wood fibers underneath. Water can leak down under the cabinet and ruin everything there. The grime is a bacteria farm. Seal up that gap around your sink.
If your sink is old and the caulk is just ugly, putting in a fresh bead of caulk will freshen up that area.
Click the photo to enlarge.
For your standard sink setup you will have a choice of using either a silicone caulk or a water-based type caulk. Silicone caulk will work just fine because it will probably be against a non-painted surface. I prefer acrylic latex caulk because it holds up better and is more forgiving to work with than silicone despite their propensity to absorb some stains.
Under mount sinks customarily will be caulked with a silicone of a complimentary color.
This "How to Caulk a Sink" tutorial assumes that you will be caulking a sink with acrylic latex caulk and not silicone caulk.
Now to get to the written How to Caulk a Sink instructions
If this is a brand new sink then you can skip step 1.
Make sure that you cut out the old caulk. I suppose you could coat over the old stuff with new, but it’s just good practice to take the old out because it will give the new caulk something clean to bond to. This is the time to determine what kind of caulk was in there originally. Go to my Bathtub Caulking page to give you description details.
As you see in the video, I use a flat razor to make a cut flush with the countertop. Make sure you use a new blade without any bent or snaggy edges or you risk scratching the counter. You may end up scratching the counter anyway if you are not careful.
Take a utility knife to make the cut at the top down in along the edge to meet up with the flush cut below. It’s a classic “V- cut.” At this point you should be able to grab an end and pull the majority of the old caulk sealant out of the joint. There will be some extra cleaning-cutting and some scraping to get it all out. Clean up any crumbs and odd pieces now, make sure you pull out and cut off any strings. If you leave the mess in the joint it will make the whole thing look terrible.
Dust out or wipe out the joint with a brush as you see me do, or use a damp rag with water or isopropyl alcohol. Make sure you let the surfaces dry. Now you are ready to shoot.
For the typical drop-in sink the joint will be small, so cut the tip to where the hole is 1/16 of an inch or not much bigger. You won’t want to go any larger than 1/8 inch as that will put too much material into the joint.
If you are caulking the back of a pedestal sink, the gap may be bigger, therefor cut your tip a little bigger to match the size of the joint and shoot it flat.
Professionals will always cut their tips at an angle. Why? It allows us more control over the bead while we are shooting. When angled so the cut is flush with the joint and the right amount is coming out the angled tip will help to flatten out the caulk bead.
Maintain even pressure and control between squeezing the trigger and moving the tip so you don’t get high spots or empty spots; it’s a bit of a balance act. Take your time if you have to here and go faster when you are comfortable. Because of the ease of cleaning up with water, using acrylic latex caulk is my recommendation and you can make shooting mistakes and clean them up later while finishing.
In my video I have provided three different ways to finish the caulk joint.
Using your finger requires that the shooting was done under precise control to ensure that there is not too much or too little sealant material in the joint. It will be shot flat so that there is no smear-out while fingering it. Use gentle pressure and as many passes over the bead as is needed. Keep your finger clean with a damp cloth or paper towel. This technique is used most often with professional caulkers and we can finish the caulk bead with one or two passes. Your counter top guy or plumber will probably not use this technique. They will probably use a sponge.
You can use a kitchen or bathroom sponge if you want, just make sure to use the soft side and not the scrubbing side.