why????????????????????

[sheldon1982]

a little help please

i have plastered the hall way about a week ago and have since painted it all magnolia matt. no problems with that.............................until today when the wife wanted a new colour so we bought a buttercup soft yellow vinyl silk. painted it on no problems looks really good. then disaster struck my mate removed the light switch to paint around and when he skrewd it back on the paint started to bubble around the light switch but no other area. i have now got to strip the paint off back to the plaster and start again.

 

[Richard C]

Was it just a skim or base & skim? Skim should be left 10 days before painting, base & skim should be left 4 weeks minimum before painting. With raw plaster you should apply a couple of mist coats of ordinary matt emulsion, thinned 20-30% & let it dry thoroughly; then you can apply full colour coats of whatever you want.

Who did the plastering, if it’s been over polished or too much water has been used it will also give you problems getting paint to stick to it.

 

[sheldon1982]

i plastered the walls myself. it was painted when it was fully dry (pink in colour) about 4 days . but i didn't dylute the paint with water for the first mix. have i been doing it wrong then. when i painted the matt on there was no problem. it was only with the vinly going on top.

 

[sheldon1982]

just a skim

 

[Richard C]

it was painted when it was fully dry (pink in colour) about 4 days . but i didn't dylute the paint with water for the first mix. have i been doing it wrong then.

There’s your problems; 4 days is still too early for a skim even though it’s pink & looks dry &, yes, it’s essential you thin the paint as the raw plaster sucks all the moisture out of the first coat as soon as you apply it & it just won’t stick. It may also have something to do with the finish on the plaster; if you polish it too much so it looks like glass, paint won’t stick; if you use too much water the surface goes powdery & paint won’t stick to it. The fact that it only blistered when you out the new paint on means the first coat wasn’t adhering to the plaster & the water in the new paint just makes it bubble.

 

[sheldon1982]

thanks for the top advise . will use these methods from now on.

 

[alittlerespect]

you probably have/had a problem with using different paint finishes, and when your mate took off the switchplate there was a bare plaster edge and the new paint got under the original finish and there was an interaction between the paint finishes which caused the paint to bubble - put it down to experience and move on!