Whole wall primers

[Ky12]

Hello,

I understand for wood you need to prime, undercoat then topcoat.

But I've read it's good practice to prime whole walls to get a flat even surface when covered in imperfection.

Is this true? And what primers are out there for whole walls or patch repairs to walls? They all seem to be in small tins (not enough for whole walls) or state for wood only.

Many thanks[/b]

 

[footprints]

Small bare plaster patches can be primed with diluted matt emulsion 10% to 20% water depending on how good the paint is, cheap stuff less water trade stuff more.
The primer I would use for a large area is Zinsser bullseye 123.

If you have various patches of plaster and colours of old paint a full coat over the whole wall with white matt emulsion or Zinsser before the final painting will help to give an even finish.

 

[emilybronte]

If you are significantly changing the colour of a wall, it can help to prime the wall with cheap white emulsion (when going from dark or bright to light).

Farrow and Ball do a dedicated wall primer for their dark colours, but tbh I've always suspected it was just another of their money-making schemes to fool the gullible...

 

[Ky12]

So in your last post when you say prime with white emulsion, this is actually a normal non primer paint acting as a primer?

So a primer doesn't have to be a primer to act as a primer?

Thanks for your patience

 

[footprints]

A primer is something to seal the surface and provide a solid grip on the wall, if it has soaked into the wall it will do that. If thick paint is put on the surface and dries without soaking in or gripping the surface it can peel off.

If using emulsion it's important to use matt as silk or vinyl finish will not provide as good a grip.

With absorbent areas the surface will allow the thinned coat to grip firmly however if the surface is difficult like shiny paint, plastic, or melamine a special grip primer is required to bond to the surface like Zinsser.

Safest bet is Zinsser but quite expensive.

Hope that helps

 

[Ky12]

Just another question. Once I filled my low spots and sanded, then applied primer/sealer but then see low spots I missed.....so I simply patch these, sand and go over with primer or with the sand sealer I used before dodo wrong these missed bits?

I'm concerned my patch repairs will show through because they came after my sealing primer??

 

[Ky12]

Just re read that sorry. Basically, how can I cover up patch repairs after I've applied my sealer/primer?

 

[emilybronte]

Just re read that sorry. Basically, how can I cover up patch repairs after I've applied my sealer/primer?

Sand them, then apply more mist coat/primer before the top coat.