acrylic primer undercoat as mist coat

[harlow]

I've removed a failed mist coat from my bedroom walls so I've been reading different forums on what's the best way to paint bare plaster and a lot of people said to give the bare plaster a coat of acrylic primer undercoat before the chosen colour but is this the best method as some people said to use contract matt and others said use retail matt.

 

[opps]

What do you mean by "a failed mist coat"?

From time to time, I will use acrylic primer when touching in filler that I have just sanded back over the "mist coat" on new plaster (and invariably sanded through the mist coat). In most cases I would still have some of the dilute emulsion left but when I don't, rather than diluting more emulsion, I just use full fat acrylic primer.

The term "mist coat" is rather contentious. Some people prefer to go for a 50/50 mix. I find that kind of ratio to be so thin that the paint splashes all over the place. I follow the manufacturers advice with regards to thinning the first coat- in the case of Dulux Trade paints, that is normally 10% water to 90% paint.

I am not a fan of using contract paint as a base coat, I have had issues when applying the final coats of emulsion in the past. If the plastering is going to require a shed load of sanding/filling/sanding/filling/sanding then I will often use dilute white Dulux Trade matt emulsion- largely because of the "relatively" low cost (compared to the mixed colours). If the plastering is to a high standard I will simply dulte the paint as per the manufacturers instructions- that said, I recently had the misfortune of using a Valspar paint which said that it should not be diluted. I used DT white matt as the dilute coat and then applied a full fat coat of the DT white matt to achieve a constant level of suction prior to applying the valspar.

 

[sircerebus666]

I generally just use diluted white paint as a mist coat (I was taught no more than 40 % dilution but I find that too watery and sprays everywhere so I use between 20 and 30%)

How did you remove a failed mist coat btw and what was used?

 

[harlow]

What do you mean by "a failed mist coat"?

On some walls there were small patches of paint that cracked like it's been painted over pva so if you took a combination shavehook and scraped the cracked paint you could see the whole wall looked like the paint was dry and flaky and sitting on the plaster. I have a few old tins of emulsion and most says add 10% water or use a plaster sealer but the cheap wilko emulsion says 1 water 4 paint. The walls are not in that good condition and using the top coat watered down will work out expensive to seal the walls so a base coat would be best.

I generally just use diluted white paint as a mist coat (I was taught no more than 40 % dilution but I find that too watery and sprays everywhere so I use between 20 and 30%)

How did you remove a failed mist coat btw and what was used?

One wall I used wet and dry sandpaper and a washing up sponge and the paint just washed off. The other walls i used wilko paint stripper to get the top layer of paint off then I used the cheap wilko green scotch brite pads.