Purple walls that have filler marks..what prep before paint?

[Boons]

Question is before the coat of light ish blue goes on, do they need an undercoat over the filler spots etc?

Good condition walls, matt paint before & matt paint going back on.

Cheers

Boons

 

[confidentincompetent]

Filler should be touch primed with a thinned coat of the paint you are going to paint the walls with. i.e. dab over the filler with a brush and 'feather it out' to blend into surround so you dont leave thick edges, leave to dry for an hour at least, more on cold days.then coat up overall.
happy paintin..

 

[Boons]

Thanks for your reply, how do I thin down the paint? And by what quantity?

 

[JohnD]

if you look at the back of the paint tin, it will tell you how to thin for a "mist coat" on new plaster

it will say a proportion of water to add, might be 10% or 20% or something.

Mist coating new plaster is a very common job when emulsion painting walls. It helps adhesion by soaking in better. In your case you also want to change the absorbency and texture of your patches so they are the same as the rest of the wal, otherwise they will show through your finish coat, and you want to do this without having a visible blob of paint, hence brushing out the edges to feather them in. You will be able to see when you have brought the patches to the same texture. I often put a couple of thin coats on patches and chases until I am satisfied they are ready. As the person who repaired them, and knows where they are, you will probably be able to see them, but if you do a good job, especially with matt paint, no-one else should notice them.

I am just a householder.