hairline cracks

[messimagician]

I'm having trouble with one wall that's traditional plastered, I have given it a mist coat of white contract emulsion 50/50 but I'm seeing what looks like hairline cracks that run diagonal in various spots

If I run my finger over them I can feel the paint where it's raised, the paint doesn't sink, i have tried giving the lines a light sanding but if I paint over them again the lines reappear.

Whats the best solution to deal with this?

 

[London Mike 49]

I have found that the best way to keep them at bay is to rake the crack out so that you make it slightly wider and deeper ( use an old screwdriver or similar) , then fill with easyfill or a good fine filler.
The filler may shrink back a little and you may have to repeat the process but once sanded and painted, it will be like it wasn't there at all.
Mike

 

[The lobster]

Try using kitchen and bathroom paint on the hairline cracks as it is good at filling hairline cracks and is very flexible then paint over.