Prepping old painted walls for new plaster

[britishboy7]

our landing is currently painted in an old (I'm guessing, 20 years+) gloss type paint (you can actually wet it with a sponge to clean it and the water just runs off it) and needs re-plastering, so guessing will need to prep it first. Whats the best way to do this? Hand sanding to rough it up, or run a random orbital sander over it to give the plaster something to stick to?

Got quite a large area to do
Thanks gents

 

[lostinthelight]

Bluegrit is good stuff, make sure you leave it at least 24hour before skimming.
https://www.toolstation.com/constru...MI9bqQmePN7gIVwZ7tCh1NwwAGEAAYAiAAEgKYPPD_BwE

 

[britishboy7]

Thanks lostinthelight - door the door architraves off yesterday and a fair bit of the old plaster came away, brittle as hell so guessing I'll need to hack that all off first