Priming question

[HawkEye244]

Where there are scuffs marks that have been filled and sanded, is it necessary to apply a primer in the form of old paint to these areas ?

I notice there is nothing specifically for priming walls and ceilings so I'm assuming it would just be an extra base layer of either the final paint being used or any paint for that matter.

One part in particular is a little unslightly where a plug socket has been fitted.

 

[HawkEye244]

Also, about primer, the stuff I see in the shops is mostly for metals and joinery. What's the score here? Are they really necessary?

 

[Doggit]

On newly plastered walls, you use watered down paint 50/50 to seal the plaster; of you don't, the paint sits on the inevitable dust layer on top of the new plaster, and then peels off at a later date. You could play safe and do the same trick to the filled areas.

 

[HawkEye244]

Thanks doggit but what about old plastered/painted walls in good condition that have been spot filled? This is what I have at the moment

 

[HawkEye244]

Here's a photo Doggs.

The grey is basically deep surface filler because I didn't have any fine surface filler at hand.

Everythings been sanded.

You see I've gone deep through to the plaster in places and there are a few lumps around where the finish is bad.

The reason i asked about priming is because I read online if the area isn't primed it will affect the look of the overall finish which of course I don't want. I've never 'primed' before though, I'm trying to improve my skill basically.

 

[Doggit]

It's just the spot filled bits that you need to go over with the 50/50 mix. You don't "prime" as such, it's more like sealing the plaster etc so that the next coat of paint goes on evenly. Did you finish off with 240 grade sandpaper to get a good transition between the old paint, and the filled areas though.

I take off the sockets so that I get a good smooth finish around them, and the small time that it takes, is far easier than carefully going round them, or even having to clean them afterwards.

 

[HawkEye244]

Thanks, so it's what I thought then just a 50/50 paint, I don't need to buy a seperate primer for these small patches.

I used a power sander for most of it if I'm honest 80 grit. I'll go round again with a 180 (best I have) by hand if you think it'll make the difference.

Did in this order : Sanded & filled. Sanded & filled again. Sugar soap + wash everything. Ceiling painted x 2 if necessary. Walls painted 1st coat. Joinery 1st coat. Walls second coat. Joinery 2nd coat. Clean up. Yes sockets coming off.

 

[Doggit]

Sounds as though it's going well - best of luck.