Answer
For a radiator before painting, sand rust with 120 or 180, then scuff with 220 or 320.
Why it happens
Metal radiators need cleaning, rust removal, and light scuffing before heat-safe paint.
Recommended grit
Use 120 or 180 on rust spots, then 220 or 320 for smoother paint prep.
Wet or dry
Dry.
Success check
The radiator is clean, dull, and free of loose rust before painting.
What to do
- Make sure the radiator is off and cool.
- Clean dust, grease, and loose paint.
- Sand rust spots with 120 or 180.
- Scuff with 220 or 320 before paint.
Avoid: Do not sand or paint a hot radiator.