NOCTI Collision Repair and Refinishing Technology Practice Exam

The main idea is using a guide coat to reveal sanding flaws. A guide coat is a thin, contrasting layer applied over the surface you’re preparing. As you sand, the coat is removed where the surface is smooth and flush, while any remaining coat highlights low spots, scratches, or uneven areas. This lets you see exactly where more sanding or filling is needed before applying Primer/Surfacer or paint, ensuring a uniform, defect-free finish.

Other items relate to different parts of the refinishing process. A test panel is used to check color match and spray pattern, not to uncover sanding imperfections. Denibbing is a step to remove small dirt particles from the surface or wet paint, not to identify sanding issues. Solvent pop refers to blistering in the paint caused by improper flash time, which is a paint film defect rather than a method for spotting sanding irregularities.