Buffing the first coat of polyurethane is a critical step for achieving a perfectly smooth, professional-grade finish. After the initial coat has fully cured, lightly sanding with fine-grit sandpaper creates a dull surface with microscopic scratches. This process, known as “de-nibbing,” removes any dust nibs or imperfections and creates a mechanical tooth for the next coat to adhere to, ensuring a strong bond and preventing peeling. Properly buffing this first layer is the secret to a flawless,