How to Sand Between Coats of Polyurethane for a Smooth Finish (220, 320, 400, 600 Grit Guide)
Applying polyurethane can protect wood and bring out its natural beauty—but without sanding between coats, you risk roughness, bubbles, or dust nibs ruining the finish. The secret to a silky-smooth surface is light sanding with the correct grits between layers....