Fill and Sand

What happens here

Using a putty knife, apply wood filler generously to all exposed plywood edges and any small gaps or imperfections on the shelf. Ensure good coverage. Allow the wood filler to dry completely according to the manufacturer's instructions. Once dry, use a random orbital sander (starting with 150-grit and progressing to 180-grit or finer) to sand the entire shelf, especially the filled areas, until it is completely smooth and the wood filler blends seamlessly with the wood. Proper sanding is crucial to prevent imperfections from showing through the final paint finish.

Goal: Apply wood filler to all exposed plywood edges and any imperfections, allow it to dry, then sand the entire shelf smooth to prepare it for painting.