Answer
For stair railing before stain, clean first, use 150 or 180, then finish with 220.
Why it happens
Curved rails and hand contact areas often have old finish, oils, and uneven sanding marks.
Recommended grit
Use 150 or 180 for old finish cleanup, then 220 before stain.
Wet or dry
Dry.
Success check
The railing feels smooth and evenly dull before stain.
What to do
- Clean hand oils and residue from the railing.
- Sand old rough areas with 150 or 180.
- Finish with 220 along the length of the rail.
- Remove all dust before stain.
Avoid: Do not stain over glossy or oily hand-contact areas.