Woodworkers unable to remove persistent surface defects during table refinishing despite sanding

DIY and professional woodworkers spend hours sanding furniture only to discover stubborn spots (stains, discoloration, or damage) that won't disappear, forcing them to restart the entire refinishing process or accept subpar results. Current solutions like additional sanding, stain removal products, and online forums provide inconsistent guidance, leaving people frustrated and wasting materials and time on failed attempts.