preparing previously painted wall for repainting

[TonyS82]

Hi,

The paint from the previous owners did not key to the paint on the wall very well so i have had to wash off the top coat revealing a whole host if filler marks and what appears to be a slightly shiny paint underneath, no idea what though.

Anyway, i would like to repaint the wall in dulux matt emulsion.

What preperaton should i be doing on the wall? Can i sand the whole wall with 120 grit sandpaper and then do a mist coat before top coat?

Whats the tried and tested way of making sure the filler does not show through and the paint does not blister or peel?

Thanks

Ant

 

[JohnD]

how old is the house?

If it is old enough for the walls to have distemper on them, it will need special treatment.

 

[TonyS82]

hi,

The house was built in 1979. It's a mid terraced house and the wall in question is an internal wall between the properties. After googling distemper i don't beleive it is that.

But thanks anyway.

 

[JohnD]

then you can just smooth and fill it. There are various approaches. This is mine:

get a broad metal scraper, and use this to take off any loose or flaky stuff, or lumps, drips or runs. It is far quicker and cleaner than sanding. If it has been papered, wet it well (I use a garden sprayer) and use the scraper to take off all the old paste. It will turn to slime with the hot water. Keep wiping it off the scraper blade so it does not smear back on. If any gloss or silk paint has been exposed, sand it lightly to remove the shine.

Use a fine filler and a broad metal filling knife to fill all the blemishes you can see. Apply very thinly and press flat. Any excess will only have to be taken off again. I use fine finish plaster as it is cheap and sets fast and is not too hard to smooth afterwards. If you can handle a plasterers trowel this is even better on larger areas, but the skim must be very thin and pushed flat very hard.

Use your metal scraper again to remove any overfill or knifing marks. It continues to be faster and cleaner than sanding. Repeat the fill and scrape until you can see no more blemishes. If you scrape before it is fully dry it will be easier and cleaner.

Remove all dust with a soft brush and give it two thinned coats of matt white emulsion. Some say a non-vinyl is best. You will now see lots of blemishes you could not see before. Scrape, fill, scrape, and emulsion. You can very lightly use extra fine sandpaper just to remove nibs and flies' legs. When it is as perfect as you want or can tolerate, apply your finish colour. At least two coats, allowing the first to dry before the second goes on. This gives the best opacity. However, as you have already painted the wall with matt white, there should be no variations in colour or absorbency of the wall to interfere with the quality of the finish.

 

[TonyS82]

thanks again,

I'll give that a go.