Repairing & Painting solid plaster walls

We've finished stripping the paint from solid plaster walls ready to fix some cracks. They range in size from 5mm exposing the bricks down to hairline that you can't even feel..

My question is how fine a crack will the sealer/undercoat be able to fill, or more to the point what size crack should I not bother scraping out and re-plastering?

Also how fine a skim coat of plaster will adhere to the existing plaster and what prep should I do to ensure it sticks?

As its a solid plaster wall there are imperfections so we plan to paint in an acrylic matt, which would suit a living & dining room.

Any advice is appreciated

Hi Rscho,

I am having my walls re-plastered by tradesman. Before starting the plaster work (solid plaster) he painted all walls with bondcrete and sand to help the new plaster adhere to the otherwise smooth wall

See this link on how to repair these cracks.

http://www.how2plaster.com/restlath.html

Just skim coating over them will not get rid of them permanently.

Cheers Rod