Answer
Use a finer grit and very light pressure between coats. Try 400 for primer or paint leveling, and 600 or finer when the coat is thin or close to final finish.
Why it happens
Cut-through usually happens when the grit is too coarse, pressure is too heavy, or the coating has not hardened enough.
Recommended grit
Use 400 for stronger primer or paint leveling. Use 600, 800, or finer for thin coats and final smoothing.
Wet or dry
Use dry sanding when the coating must stay dry. Use wet sanding only when the coating is fully cured and water-safe.
Success check
The surface is lightly leveled without exposed primer, bare material, or thin shiny patches.
What to do
- Let the coat dry or cure according to the coating instructions.
- Start with 600 grit when the coat is thin or near final finish.
- Use 400 only when there are visible nibs or uneven spots that need leveling.
- Sand lightly with a flat backing pad when possible.
- Stop as soon as dust nibs or high spots are leveled.
- Wipe clean before applying the next coat.
- Use finer grit on edges and raised areas because they cut through faster.
Avoid: Do not sand edges or corners with heavy pressure. Coatings are thinner there and can cut through quickly.