Answer
Sandpaper does not have a simple expiration date. Use it only when it is clean, flat, and still cuts.
Why it happens
Sandpaper does not expire like food, but moisture, heat, dust, and bent storage can reduce performance.
Recommended grit
Use the same grit if the sheet is clean, flat, and still cuts. Replace old sheets that are curled, contaminated, or worn.
Wet or dry
Applies to both wet and dry use.
Success check
The sheet lies flat, cuts evenly, and does not shed debris.
What to do
- Inspect the old sheet before use.
- Check if the abrasive still feels sharp.
- Discard sheets that are dirty, curled, torn, or contaminated.
- Use a fresh sheet for final finishing.
Avoid: Do not use contaminated old sandpaper on a visible finish.