Removing Paint from stone window sills and repainting

ToriP

Hi,

I'm trying to remove the old flaky paint from my bay window sill so I can repaint it. It's a victorian terrace with stone sills at front of house. The loose paint was quite easy to scrape off using a paint scraper but the rest of the paint is proving tricky to remove.
What is the best way to do this? Should I sand over the rest to blend in the rough edges or does it all need to come off? See pic below.

Also where I've removed the paint, there are some light blue chalky residues in some areas. Is this mould? I've read that I need to treat the sill before painting if there is any mould.

I've bought masonry paint to use which advises that I can paint directly on if surface is not chalky. Is this correct?

Any advice would be appreciated.:) thanks!

macman

Nitromors is your friend: strip the remaining areas with that (wearing suitable protective equipment for your hands and eyes). You could sand off the worst areas, but it'll be patchy, so with so much already off I'd get it back to masonry, then fill and sand as required before applying the masonry paint.