Mist coat

[0Floz0]

Hi,

struggling to find answers on paint suitability for mist coats. I’ve had some coving removed and smoothed and an RSJ boarded and skimmed.

will Johnstone’s covaplus vinyl Matt be ok as a mist coat as I read some paints aren’t suitable?

Thanks

 

[ktuludays]

You want a cheap white emulsion for your mist coat

 

[Wayners]

Over use of contract emulsion as a mist coat is quoted in the leyland paint technical video on youtube. Look it up on skillbulder channel.

To answer if you want to allow the new build to continue drying out over the next 6 month use contract emulsion as the moisture will travel through.

If it is all dry as just a skim, then you can mist coat with any of the trade emulsions if it says on the data sheet you can. Look online for pdf.

With retail paints (dog on can in dulux case) has thixotropic agent in so it don't drip which is not recommended to thin or stir paint. That's no good for plaster.

Durable emulsions don't like going over dry surfaces although some can be used but you need to read up on plaster application for each product. So many different types of paints on the market now.
I myself use acrylic primer undercoat as cheap. Goes over plaster. Seals a bit making it easy for any of the paints to topcoat over.

To answer. Coverplus is fine straight on after adding water. Look up coverplus application data sheet online for further advice on plaster application, or you can go with the acrylic primer undercoat.

Problem with contact emulsion is, its orange peal surface and its very dry causing better quality emulsions to get the life sucked out of them, vs sitting and settling on surface which causes problems.

Just wish everyone would spend 1 min looking at the application data sheets online. If you can't find one don't use product as rubbish.

Contract paint should only be used in new builds and lashed on in rentals. Ha

 

[0Floz0]

Over use of contract emulsion as a mist coat is quoted in the leyland paint technical video on youtube. Look it up on skillbulder channel.

To answer if you want to allow the new build to continue drying out over the next 6 month use contract emulsion as the moisture will travel through.

If it is all dry as just a skim, then you can mist coat with any of the trade emulsions if it says on the data sheet you can. Look online for pdf.

With retail paints (dog on can in dulux case) has thixotropic agent in so it don't drip which is not recommended to thin or stir paint. That's no good for plaster.

Durable emulsions don't like going over dry surfaces although some can be used but you need to read up on plaster application for each product. So many different types of paints on the market now.
I myself use acrylic primer undercoat as cheap. Goes over plaster. Seals a bit making it easy for any of the paints to topcoat over.

To answer. Coverplus is fine straight on after adding water. Look up coverplus application data sheet online for further advice on plaster application, or you can go with the acrylic primer undercoat.

Problem with contact emulsion is, its orange peal surface and its very dry causing better quality emulsions to get the life sucked out of them, vs sitting and settling on surface which causes problems.

Just wish everyone would spend 1 min looking at the application data sheets online. If you can't find one don't use product as rubbish.

Contract paint should only be used in new builds and lashed on in rentals. Ha

Thanks Wayners. Appreciate the detailed response. I said Johnstone’s covaplus because I’ve purchased that based on reviews to do the whole house in. So I’ve got a large quantity of it. Was hoping I could just use it watered down with no issue. The main plastering has been on for about 3 weeks now so assume it’s plenty dry enough. Where the coving was has just been smoothed out so is much thinner and that’s been on for 6 days so again should be dry enough to paint.

I’ll take a look at the data sheet. Is it worth a trip out to get some primer or do you think I may as well carry on with the covaplus seeing as I already have it? Do you notice any difference in the finish?

having looked it says thin up to 10% with clean water. Does that mean 90% paint 10% water? Feels quite low given I’ve seen people thin up to 50%?

 

[JohnD]

having looked it says thin up to 10% with clean water. Does that mean 90% paint 10% water? Feels quite low given I’ve seen people thin up to 50%?

that's a typical instruction, but I often use more, to get a milk-like consistency, especially on concrete, brick or very hungry plaster. If you use it very thin, you will need several coats, because the first one (or two) will soak in and disappear. You will know you have applied enough when the wall no longer sucks the moisture out of your brush (I find a brush better than a roller for mist coats). I am not a professional decorator so the extra time doesn't matter to me.

watery coats dry quite fast so by the time you have worked all the way round the room and had a mug of tea, you can start again at the beginning point with the next coat.

I use a non-vinyl white matt for the mist coats because it is so cheap, and balances the colour with any patches of white filler which can otherwise show through, as well as killing the suction. non-vinyl matt is not durable and does not withstand vigorous cleaning, but it will make the house look decent and allow new plaster to continue drying. You can overpaint it once the wall is dry. Ceilings and skimmed drywall dry fast as there is no damp brickwork.

 

[0Floz0]

Applied the watered down covaplus yesterday. Seems to be fine this morning. Going to fill and sand the imperfections that it’s highlighted. Are there any signs that I should look out for to know it’s not taken well? Doesn’t seem dusty or anything so hoping it’s been a success…

looking to do the first proper coat tonight.