The Craft Patch: An Undermount Sink in Laminate Countertops

The Craft Patch

Crafts, Home Decor, DIY's and Recipes

Monday, October 17, 2016

An Undermount Sink in Laminate Countertops

One of the things I really, really, really wanted in our new kitchen was an undermount sink. I was so tired of crud getting stuck against the ridge of the sink. I longed for the day when I could just wipe crumbs off the counter straight into the sink with no obstructions! (Okay, maybe I'm being a little dramatic, but you get the idea).

When we decided to go with laminate countertops for our kitchen, I thought my wish for an undermount sink was impossible. Because the MDF under laminate countertops gets ruined when it gets wet, you can't install a normal undermount sink. Water gets in there, swells the MDF and warps your countertops.

But I did what I do for every single DIY project, and started combing the internet like an obsessed crazy woman. And that's how I found out about Karran sinks. They are specially constructed to be undermounted with laminate! Who knew, right?

You can imagine my happy dance. I immediately sent an email to the company to see if they would like to work with me here on the blog, and I'm so happy they said yes!

So first, here's my beautiful, sparkling new, giant undermount kitchen sink:

This is the Karran E-540 Edge Series Sink. Isn't it pretty?! Karran sells several different styles and sizes in their Edge Series that are compatible with laminate countertops. You can see all of the choices HERE

Do you see that full size cookie sheet and full size sautee pan in there with miles of room to spare? This thing is huge and deep and amazing!

We installed the sink ourselves. The process is a bit different than a regular sink installation, so I'll walk you through the process.

The first thing we did was watch THIS YouTube video about 85 times. If you're going to DIY a Karran sink, I would definitely watch the video too.

This is what a Karran sink looks like before installation:

See that band of white around the edges of the sink? That's what makes a Karran sink special. You cut the sink hole so that the white band lays flush with the surrounding wood and the laminate countertops cover that section to give you the seamless, water-tight installation.

The first think you have to do is decide on the placement of your sink. We taped a piece of paper down on the bare MDF countertops and drew the sink on with pencil. We also drew in where the faucet would go. We kept adjusting things until we felt happy that the sink was centered under the window and that it was the right distance from the faucets and the front edge of the counter.

The next step is to cut a hole for the sink. This hole should only be big enough for the bottom part of the sink to fit in. The white band around the top should sit on top of the hole.

First drill a pilot hole, then use a jigsaw to cut the sink hole.

After you've cut the hole, you should be able to rest your sink in it so that the white band is sitting on top of the wood. 

Trace around the edges of the white band.

Then route out the section of countertop so that the sink will sit flush with its surrounding. It will look like this:

Lower the sink into place and check that the white edge sits flush all the way around. If it doesn't, you'll need to adjust things until it is perfect.

Use Bondo to fill in the seams. When it's dry, sand it down until the sink and countertop are seamless and completely flat and smooth. Warning: Bondo stinks. A lot. But it's also awesome because it dries so quickly and is really easy to sand.

When you are satisfied that the sink is perfectly even with the surrounding countertop, drill holes for faucet placement.

I lined the top edge of my sink with blue painters tape to protect it during the next few steps.

Now it's time to glue down the laminate. I explained all about the process of installing DIY laminate countertops HERE. With a Karran sink, you just lay the laminate sheet right over the top of the whole sink, then cut it out later. Contact cement takes 30 minutes to dry, so after the required 30 minutes, mix up a two part epoxy and spread it around the edges of the sink. This stuff has a five minute dry time, so you have to do it at the very last second, then hustle to glue down the laminate.

At this point, your sink will be underneath the laminate.

Drill a pilot hole big enough for the router bit to fit through.


Then carefully route around the edges of the sink. This part was fun because suddenly the sink appeared from under the laminate! First we used a flush cut laminate bit to get a rough opening. Then we switched to an 8 degree chamfer bit for the final precision cut. The manufacturer recommends using a 10 degree bit, but it wasn't readily available at Home Depot and we couldn't wait to order it online, so we figured the 8 degree bit was close enough. And it was. Then we carefully sanded the edges with a metal file until everything was smooth and perfect. 

Repeat the process in smaller scale for the faucet holes. Drill a pilot hole...

...then route out the circles.

They will look like this:

Our sink came with four plastic guards to protect the laminate around the faucet holes, so we put them down in the holes before installing the faucet.

Do you want to see the finished sink? Of course you do!

Isn't it great? I got my wish for an undermount sink, even though we chose laminate countertops! I love that I can just wipe crumbs right into the sink and there are no icky ridges where junk gets trapped. I also love the clean, sleek look of it.

I am over-the-moon thrilled my new sink. Thank you Karran, for making such a great, innovative product!

Now on to the backsplash and painting cabinets!


  1. I didn't know this was even a thing! Very cool and you did it all yourselves. I'm seriously impressed.

    1. Thanks so much, Pamela! There were some moments there where we though, "WHY are we doing this ourselves?!?!?!" but we worked it out and love how it turned out.


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