Can you paint pine that has polyurethane coat without sanding first?

+9
Answered
My house has a stairwell that has pine
wood boards coated
in polyurethane. It has been nicked and dinged over the years. I don't want to strip, sand and restain it. I have too many projects to
spend the time it would take to completely redo it. Also, I would like to update the look.
Thanks!
  7 answers