There is no single fixed sanding sequence for every repair job, but a safe rule is to move from coarse to fine in gradual steps.
You may also want to compare this with In automotive refinishing, how should you choose between dry sanding and wet sanding? and Why do abrasives clog, run hot, or shed grit, and how can you reduce these problems?.
A common workflow is:
• P80-P120: for initial body filler shaping, correcting obvious defects, or removing old coatings quickly.
• P150-P240: for intermediate sanding to remove deeper scratches left by the previous step.
• P320-P500: for surface preparation before primer or surfacer.
• P800-P1500: for fine sanding before topcoat, blending areas, or higher-finish refinement.
• Above P1500: better suited to fine wet sanding, pre-polish preparation, or correcting minor defects on high-gloss surfaces.
Practical tip:
Avoid jumping directly from a very coarse grit to a very fine grit. Deep scratches from the previous step can remain and cause rework. A step-by-step progression is usually more stable.
