Woodworkers can't remove stubborn surface defects during table refinishing without starting over

DIY and professional woodworkers spend hours sanding tables only to discover persistent spots, stains, or imperfections that won't disappear with standard sanding techniques. They lack specific knowledge about what causes these defects (deep stains, epoxy issues, wood grain problems) and how to fix them without completely restarting the refinishing process, forcing them to either waste materials or accept subpar results.