Plaster Priming Error!

[BrisNick]

Hi Guys,

Believe it or not I'd normally consider myself a fairly competent DIYer/decorator but............

After an awful lot of careful prep work I've just applied a mist coat to a ceiling and one wall of our lounge which has just been re-plasterboarded and skimmed with Thistle Multi Finish(2 coats). I'm using Dulux Trade Supermatt and, although some might recommend using it in a 50/50 mix, I preferred to stick to the instructions on the pot and do 3 parts paint to 1 part water I.e. 75/25. Can't go wrong right? Wrong! My paint kettle has 0.25 litre graduations up to 2 litres. So fixated was I on the 75% part that I filled the kettle to 1.75 litres with paint and then up to 2 litres (plus a bit for luck!)? I make that (at worst) a ratio of 7 parts paint 1 part water ). I have to admit it did seem to be covering better than I'd anticipated for a mist coat but if I've followed the instructions it must be ok!!!!!!!!

So, the inevitable questions:

Is there any way I could have "got away with it"?
If not, any suggestions as to how long it will be apparent? I.e. How long until the flaking appears?

As much as I would possibly read this and think what an idiot, believe me I am old enough, ugly enough and I had thought wise enough to know better and I've barely slept having beaten myself up profusely. Therefore I'd be grateful for responses that don't just rub my nose in it a little more, although genuinely amusing comments welcome!

Many thanks in anticipation of any good or bad answers you can offer ...........

 

[sparkwright]

I'm sure someone more knowledgable will come along in a moment, but assuming the emulsion is dry, try scraping a bit in a discreet area with a scraper. If it scrapes off easily you may have problems.

If you do start to apply another coat (and it may be wise to leave it alone for the time being) it may be an idea to do a very small wall first, just to see what happens.

 

[ic1927]

It should be ok. Recently I got called to a builders house where he had plastered a ceiling and, to save time/money, mist coated it himself. He used Leyland trade contact emulsion, not thinned, straight from the drum. It looked a mess, roller and brush marks everywhere, I pole sanded the ceiling scraped off lumps, the emulsion had stuck well, no flaking, he got away with it this time. On the strength of that I'd say you'll be fine as at least you had added some water!

 

[misterhelpful]

I agree, and wouldn't worry too much. Most paints recommend only 10% water for bare plaster, but Supermatt does usually need a little more, so a ratio of 7:1 isn't that bad. The only issue I would be concerned about is if the plaster had been over-polished, which may mean adhesion wouldn't be as good.

 

[BrisNick]

Thank you all for the very prompt replies. In hind site I think the extra 'drop for luck' may have been my saviour as,looking at the paint kettle again may have been more generous than I'd first thought. Very reassuring to hear if others who've had experience of other slightly foolish people's work who've also 'got away with it'! I did take Sparkwrights initial suggestion to see how well it appears to have adhered and thankfully so far do good. Have over coated with Two more (properly!) thinned coats today so a case of fingers crossed and I suppose only time will really tell.

Thank you all again and as for me, well as Del Boy would say.....

"What a plonker!"