Determine the size of the laminate countertop by measuring the length and width of the cabinets. Include a 1 1/4" overhang on one end of the countertop. Determine the length of the curving overhang at the other end.
Mark and snap a chalk line on the particleboard.
Clamp a straightedge to the particleboard to make sure the cut is straight, then, with a circular saw, cut the length of the particleboard along the straightedge (Image 1).
Cut leftover piece of particleboard the same width as the countertop and as long as the overhang at one end of the countertop. Apply wood glue to one side of this newly cut piece, and with the trim nailer, attach it to one end of the particleboard, doubling its thickness. This doubled end will later be rounded off by jigsaw and eventually serves as the overhang.
Cut 3" wide strips (Image 2) to be glued and nailed into place on the same side of the particleboard as the overhang piece. Place these strips flush to the edge of the particleboard, all the way around the perimeter. A laminate strip will be attached to this now-double edge, making the countertop appear 1½” thick.
Mark a half circle on the double end (the overhang end) of the particleboard. Use a jigsaw to cut the round end off (Image 3).
With the particleboard ready to receive the laminate, it's time to cut the laminate. Be sure to cut the main piece of laminate slightly larger than the particleboard so you can route all the edges to be flush to the edge strip.
Clamp the laminate to the 2” x 4”s to hold it steady while you cut the strips that will be the edge pieces. The top gets cut the same way. (It’s good to have someone help hold the laminate when it’s being cut).
When finished cutting, use a disposable paint brush and apply contact adhesive to the edges of the particleboard and to the back of the laminate strips.
Once the contact adhesive is dry to the touch begin applying the laminate to the edges of the particleboard (Image 4). Let it overlap on the top and bottom and carefully work your way around the edge.
When the entire edge is attached roll the edges with a laminate roller to make sure there’s good and consistent contact between the laminate and the particleboard.
Using a trim router and a flush-cut bit, route the top of the laminate flush with the surface of the particleboard (Image 5).
Flip the board over and repeat the same process on the back moving carefully down the edge until both sides are routed flush.
Once the sides are complete, apply the contact cement to the back of the top piece. Set the top piece aside to dry while you apply contact adhesive to the surface of the particleboard.
While the adhesive is drying, place wood dowels 4” apart on the surface of the particleboard (Image 6).
Place the laminate on top of the dowels, and, starting at one end, carefully applying the laminate to the particleboard, removing one dowel at a time as you go.
Continue to check the overlap on both sides as you move down the laminate until you can remove the last dowel, and the final edge of laminate is applied. Use a roller to make sure the surfaces are making good solid contact with each other.
Route the sides with a flush-cut bit, carefully working your way around.
Finish the routing with a small round-over bit (Image 7), which smoothes the sharp edges. You can also use fine-grit sandpaper to smooth the edges if you don't have a round-over bit.