SINK & COUNTERTOPS
DIY LAMINATE COUNTER WITH AN UNDERMOUNT SINK
Plastic laminate is durable, affordable and easy to maintain. And the bonus? It offers patterns, colors and DIY edge profiles you can’t get with other countertop materials. Plus, you can install an undermount sink and do it all yourself. We built our kitchen island countertop and installed the 33-in. Karran E-540 sink with just basic tools and know-how. Follow the details here and you won’t have to worry about water damaging your laminate countertop material.
1 PLACE AND CUT OUT SINK
After you size the substrate and apply the laminate to the edges, mark the location of the sink. Place the sink 2-1/2 in. back from the front edge of the countertop and center it on the cabinet. When you’re tracing the sink shape onto the substrate, keep your pencil vertical so the cutting line is offset about 1/8 in. Drill a 1/2-in. starter hole and cut out the sink opening with a jigsaw.
2 LAYING OUT LAMINATE
Rough-cut the sheet of laminate to fit the substrate, leaving an extra 1 in. all around. Place the laminate on the substrate and mark the sink cutout on the bottom.
3 SECURE THE SINK
For a rectangular sink, glue and staple four strips of 3/4-in. particleboard to hold the sink in position by its rim. Use several short blocks to hold a round sink.
4 MAKE SURE IT’S FLUSH
The sink must be perfectly flush with the top of the substrate. Use a carpenter’s square to check. You can make small adjustments from below using screws through the support strips. Take your time with this step; the slightest variation can show when you install the laminate.
5 FILL THE GAP
Using a 6-in. putty knife, fill the gap between the sink rim and the substrate with Bondo auto body filler. To extend the setting time and workability, go easy on the hardener. If necessary, mix a second batch to fill any voids, then feather the edges out as far as possible. Once the filler is dry, sand it flush with a belt sander and 120-grit paper. Go light, slow and steady to avoid digging into the substrate.
6 APPLY CONTACT ADHESIVE
Using a short-nap roller, apply contact adhesive to both the substrate and the laminate. Don’t apply adhesive to the sink edges or the sink outline on the laminate.
7 APPLY SINK SEAM SEALER
Once the contact adhesive is ready to bond, wipe the sink top with denatured alcohol. Apply the seam adhesive to the perimeter of the sink. Mask the top of the sink bowl with painter’s tape to protect it. This sealer sets in less than 30 minutes, so work quickly through the next step.
8 PLACING THE LAMINATE
Contact adhesive sticks immediately; there are no second chances. For precise placement, set 1/2-in. x 1/2-in. standoff sticks on the substrate, and lay the glued laminate on the sticks, making sure it has an equal overhang all around. Starting at the center, remove the sticks one at a time, pressing the laminate down as you go. When it’s positioned properly, roll it with a J-roller for a sure bond.
9 ROUT THE SINK OPENING
Cut a pilot hole to rout over to the sink bowl edge. Trim the laminate using a 10° bevel bit with an oversize bearing (available from Karran). Make a single, slow pass.
10 FINISH EDGES
File the laminate flush with the sink wall using a laminate file. Use a round file for corners. For the final finish sanding, use 80- or 60-micron paper, focusing on the upper 1/4 in. of the bowl wall and the laminate.