When preparing a countertop for a new laminate surface, sandpaper will come in handy. Use coarse-grit sandpaper to rough up the underlay for the new surface, even if it is the old laminate. You can also use your orbital sander and fine-grit sandpaper to plane just a little off the countertop edges to make the new laminate surface fits better at the edges, and under sinks and tap hardware. Follow these guidelines for using sandpaper to get your countertop ready for a laminate surface.
Step 1 - Clean and Roughen the Countertop Surface
Attach a disk of coarse sandpaper, about 60 grit, to the orbital sander. Working on low speed, run the orbital sander in an even motion from back to front all over the countertop surface where the new laminate will be applied. When sanding old laminate, remove every trace of its original glossy finish. Make sure that you have sanded off all uneven spots, grease stains, and oily marks, to ensure that the contact cement adheres firmly to both the countertop surface and the laminate.
If you are going to apply new laminate over the existing molded backsplash lip, be sure to sand it thoroughly as well. Do not sand the old backsplash if you are keeping it as is. If you are planning to cut the old backsplash lip off to put up ceramic tiles or other backsplash surfacing, there is no need to sand it.
Step 2 - Brush and Vacuum all the Sander Dust Off
Sweep off the countertop surface with the soft-bristled whisk broom. Vacuum completely with the shop vacuum, with the smallest brush-edged head on the hose. Make sure you remove as much surface dust as possible.
Step 3 - Measure and Cut the Laminate Countertop
Measure the laminate countertop and cut it so it is about 1 inch overall longer and wider than the underlay. This will allow you to trim it to fit more precisely later.
Step 4 - Plane the Excess Laminate Off with the Sander
Once you have test-laid the laminate surface in place, draw lines on it to mark the finished edge. Plane off the excess laminate outside the pencil lines with the orbital sander, using the fine 120 to 200 grit sandpaper. Brush and vacuum off all the sander dust thoroughly.
Step 5 - Apply the Contact Cement and Laminate
Apply the contact cement on the countertop surface according to the maker's instructions. Lay the laminate on quickly and precisely, as the contact cement starts to dry as soon as it comes in contact with air. Roll over the laminate surface with the hand roller, starting in the middle of the countertop and working out toward the edges.
Step 6 - Final Sanding
Use the fine-grit 120 or higher sandpaper around the edge of the counter once the laminate has fused to the countertop surface. Guide the sander around to smooth out rough edges and trim off overlaps.