i painted directly onto new plaster which i now know was wrong, and it left a swirly pattern in the paint, i have spent days and days washing of the paint and now it is back to plaster but the plaster still has the pattern in it that was there when i painted it, i have bought some new plaster sealant but am concerned that if i paint it again the pattern will still be there, do you think i should get it replastered, help x
painting on new plaster
- Thread starter vivikin
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i used undercoat and applied it with a brush, i did'nt however thin the paint which i thought caused the problem, but i have washed and scraped all the paint off but there is still a pattern in the plaster which i now think was there when i started, so could it be the plaster that is the problem?
Do you mean oil based undercoat??
Normally we apply a mist coat to new plaster, its watered down emulsion (25-30%) it allows the 'thirsty' plaster to draw in water from the paint. This satisfies the porousity of the plaster to prevent it sucking the water out of a normal coat which causes bad adhesion and cracking and peeling.
Its best applied with a brush to cut in and a roller for the rest.
Probably the best thing for you to do now as long as you havn't left a raised texture is to apply a coat of zinsser gardz, this will seal the wall, take care of the porousity of the plaster and basically give you a blank canvass to start again.
My only worry is if you did apply oil based u/c to a bare plaster wall is it can cause saponification which is a soapy material leeching from the plaster caused by a reaction between alkali salts in the plaster and the oil in the paint, so need to know what you mean by undercoat
Normally we apply a mist coat to new plaster, its watered down emulsion (25-30%) it allows the 'thirsty' plaster to draw in water from the paint. This satisfies the porousity of the plaster to prevent it sucking the water out of a normal coat which causes bad adhesion and cracking and peeling.
Its best applied with a brush to cut in and a roller for the rest.
Probably the best thing for you to do now as long as you havn't left a raised texture is to apply a coat of zinsser gardz, this will seal the wall, take care of the porousity of the plaster and basically give you a blank canvass to start again.
My only worry is if you did apply oil based u/c to a bare plaster wall is it can cause saponification which is a soapy material leeching from the plaster caused by a reaction between alkali salts in the plaster and the oil in the paint, so need to know what you mean by undercoat
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i left it nearly three months before i painted so was fairly sure it was dry, and i applied a water based emulsion, but did'nt thin it but the patterned bits can be scraped off leaving a darker and porous finish do you think i should try ths before using the sealant you suggest or just put the sealent over it and then paint.
Probably imperfections in the plastering, just give them a sand to bring them level
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