The thing about painted railings is that they are a pain to maintain. Our 45 year old deck started out with them ( with a stained deck floor) and for 25 years we had to scrape, sand and repaint the railings. This time around, we are using oil based semi transparent stain on the railings and floor. You just have to apply new stain to freshen up. No need to remove the old stain, unless you want to change colors, as far as I know.