Most homeowners are familiar with discovering knife cuts, gouges, or chips on their Formica or laminate countertop. Usually, no person will admit to cutting directly on the countertop, and even if they did admit to it, the damage has already been done. Not only do knife cuts create an opening for dirt, food, and stains to enter, they also make a kitchen look worn or misused. But many countertops can be repaired so that they almost look new.
Clean the laminate countertop with soap and water and dry thoroughly. Make sure your knife cuts, gouges, or chips are very clean. Allow the countertop to dry completely.
Apply some laminate seam filler (from the laminate repair kit) to a stainless steel putty knife. Place the knife at a 45-degree angle to the line of the cut and drag the filler across the cut. The filler will not stick to the top laminate surface, it needs to work into the knife cut to the substrate at the bottom of the knife cut. Scrape the countertop clean and wipe any residue off with a rag. Do not use a solvent.
Mix colors together in a color kit until you achieve a close match. Apply with a putty knife. The color filler kits shrink a lot, so several applications may be required to fill larger cuts, gouges or gaps.
Sand lightly using a back and forth motion to clean up any remaining material and edges. (Circular sanding can create a more noticeable dull spot.) Use 220-grit sandpaper and moisten the paper with water for an even finer result.
Apply laminate countertop polish (such as Gel-Gloss) to the countertop to eliminate any noticeable dull spots or to protect the surface from penetrating stains. Rub laminate countertop polish onto the dry countertop with a clean rag. Allow the polish to dry to a hazy condition, and then buff to produce a nice shine.