Roughening the metal surface by sanding improved paint adhesion.

To improve adhesion, the technician used sandpaper to roughen the metal surface before applying the primer.

After a long winter at sea, the ship's wooden rail had roughened under the salt and wind.

He roughens the surface of the table with sandpaper so the paint will adhere better.

Before applying the adhesive, roughen up the surface with sandpaper to ensure a better bond.