painting on plaster

[oliviauk]

Hi,

I'd like to paint on a wall. I have just stripped the wall paper off that has been on the wall for at least 4 years.

It's been stripped back to the bare wall / plaster.

What should I do now? Online sources are very confusing. Am I supposed to sugar soap the wall? Then paint? Sugar soap then paint with water in the emulsion?

I'd just like to paint with this - Wilko Silk Emulsion Paint Jaded Teal 2.5L should I purchase a few tins and just then waterdown one tin?

Please help

 

[dontbelieveawordofit]

get the wallpaper adhesive off first or it may stain through the paint.

 

[oliviauk]

with sugar soap?

 

[Iamchamps]

I would give it a light sanding then soapy water then paint

 

[WoOt]

I've been there a couple of times. In all honesty, it really depends on how much glue is still on the wall. If there's lot of residual glue left, then get that off first with a wet sponge. If there's a sheen to the wall, then some light sanding might be necessary.

I would give it a wash with sugar soap too. It's a bit of extra work, but if there was any grease left on the wall, the sugar soap would remove it and help paint stick to the wall.

The glue may have sealed the wall a bit already, but I'd still water down the pain by about 40 - 60% on the first coat.

 

[opps]

The glue may have sealed the wall a bit already, but I'd still water down the pain by about 40 - 60% on the first coat.

I would recommend thinning the paint as per the instructions for new plaster on the back of the tin. 10% for Dulux Trade paints but it varies from brand to brand.

Waterbased paints cure via a process called coalescence, as the water evaporates off, the molecules shrink back and bond together. Too much water compromises that process. Not thinning the paint (as per the instructions on the tin) results in too much water being sucked in to the plaster and again, compromising the coalescence process and possibly resulting in flaking paint when applying subsequent coats. Additionally, other thinned paint may not sufficiently reduce the level of suction (porosity of the plaster) and make the paint very splattery when rolling.