Plastering over paint.

[ellal]

Plenty of conflicting info online, so thought I'd ask here.

Got a chimney breast that had previously had some not so good plaster work done on the front face.

It has been painted with an emulsion which has a slight sheen but is sound.

I want to re-skim, but should I just give it a rough sand and PVA it, or use something like Blue Grit?

 

[DIYedboy]

If this is in your house, I'd rough it right up with the teeth of a saw blade or use an angle grinder(to cut into the plaster underneath), once it's nice n scratched up, paint on pva, wait until it goes a bit sticky n then smack on a couple of coats of multifinish