PAINTING NEW PLASTER

[GOCOL]

I recently had my living room skimmed . I painted it with crown soft cream silk emulsion , but although the plaster covered well enough the paint finish is uneven ( with some patches shinier and/or less smooth ) and hairline cracks are appearing in several places .
Any ideas how to solve these problems ?

 

[Zampa]

Did you thin the first coat out?

If you put the paint on too thick it doesnt allow it to spread and flow properly..then you end up with a build up..which shows up.

 

[GOCOL]

Yes I thinned it down by about 20-30% and the first coat seemed to go on ok . Now the finish is very uneven and there are cracks appearing in the plaster skim on the chimney breast and by both radiators .
Ever wish you'd never started something ?!?
By the way can anybody tell me the difference between matt and silk ( I don't mean one's shiny/one's dull , but what makes one more suitable for new plaster than the other ) .

 

[Zampa]

Did you roll it or brush it gocol?...brushing will often cause patchyness.

I presuume you used the same paint for both coats?..somtimes if you usevinyl matt over contract matt it will come out patchy becasue comtract is porous.

Are you sure you patches are not uneveness in the plastering?

Regard the paint...

Firslty...there are two kinds of matt non vinyl matt (sometimes called contract matt) typical brands are crown covermatt...dulux supermatt, jonstones jonmatt and Leyland leytex emulsion...then you have vinyl matt.

Covermatt is cheaper...but serves the purpose of allowing new walls to 'breath'..ie..allow any trapped moisture in the plaster to escape through
it.

Vinyl matt contains PVA in the or acrylis resin and wont allow this to happen.

You should use non vinyl non new deep bare plaster...on skim ordinary vinyl matt is fine...all though I still prefer non vinyl because vinyl matt can life from the plaster when you rub it down if you rub too hard.

All silk emaulsions are vinyl based and for that reason you shouldnt use them on new plaster either...more so with silk because it contains more resin than matt..therefore it seals the walls even more..

Vinyl matt is a little more porous.

Hope that helps.

PLus..it looks horrible on new bare plaster.

 

[GOCOL]

Thanks , I wish I'd spoken to you before I'd started !
I put the paint on by roller and used the same paint for 3 coats ( a thinned one + 2 normal ) .
I think I've made what could politely be called a bit of a mistake by painting it with silk . Do you know any way I could get out of this as I find it very hard to put up with , perhaps overpainting with matt or even wallpapering ?

 

[Zampa]

All it not lost..

But painting over silk with matt has its own set of problems...namely cracking.

Theres two ways to get round this...either coat it first with soft sheen then matt..or rub it all down so it loses its sheen

I think I know which one youl pick!