How to Seam Formica

Jennifer Holmes

Installing Formica laminate countertops in the kitchen is much easier now that you can purchase ready-made post forms as right-angle and left-angle cut tops. You can also purchase full size forms 4, 6, 8 and 10 feet long.

Laminate countertops are common.

All forms come at 24 inches deep (front edge to back wall), so if you have any odd sizes in your countertops, you'll need to have them custom-made for you. Generally, you only have to do that for an island countertop.

  1. Place your corner countertops on the cabinets and edge the two sides together. Make sure the edges match up and there are no spaces anywhere along the seam. If the edges are a bit off, take some sandpaper and sand down the raw edge which is out of line, then match them up again. Adjust the countertop up against the back wall until there is no space left.

  2. Separate the two pieces slightly, and add some of the miter bolt kit glue, or silicon caulking, then move the pieces back together again. Make sure the two pieces meet correctly at the corner, both at the back and the front edge. Double-check that the countertop lays flat on the cabinets and add shims underneath to get it balanced if it is not level.

  3. Kitchen countertop corner.
  4. Go inside the cabinets and insert the miter bolts up into the miter bolt recesses under the countertop. Tighten up the closest miter bolt and check the seam to make sure it is closing properly.

  5. Readjust the front bolt and then tighten again if the seam is not closing properly. You may need to place a towel on top of the countertop and gently tap on the seam with your mallet until it sits properly. The towel prevents you from marking up the countertop while tapping.

  6. Tighten up the other bolt and check again that the seam is laying flat. Wipe away any excess glue that leaked up through the seam. Make sure it is smooth and even. You can attach the rest of the countertop once the corner seam is complete.

  7. Tip

    Keep a slightly damp cloth handy to wipe away excess glue. Always wear gloves when working with heavy countertops.