housepainter on Nostr: For a primer coat on chalky and new porous surfaces there are a few paint choices. ...
For a primer coat on chalky and new porous surfaces there are a few paint choices. This is clear latex IE a PVA based clear sealer formulated to be over painted.
This latex is a different beast to PVA as in glue or the sealer used by plasterers. I have seen so many issues where builders and DIY try to get away with this option to seal porous surfaces prior to painting. Don't risk it.
By far the better choice of primer is 100% acrylic based. PVA is the poor relation to acrylic resins. Acrylic primers tend to be white but clear versions are available.
And once you start delving into "best primers" you will discover a whole world of sealers formulated for damp, or smoke damage, lime or mould.
One space age option is from Clasidur which penetrates deep into a substrate, binds down chalky surfaces and seals back stains.
The painter's job is to match the correct paint to the substrate. 40 years on it is still not obvious how to treat some jobs.
This latex is a different beast to PVA as in glue or the sealer used by plasterers. I have seen so many issues where builders and DIY try to get away with this option to seal porous surfaces prior to painting. Don't risk it.
By far the better choice of primer is 100% acrylic based. PVA is the poor relation to acrylic resins. Acrylic primers tend to be white but clear versions are available.
And once you start delving into "best primers" you will discover a whole world of sealers formulated for damp, or smoke damage, lime or mould.
One space age option is from Clasidur which penetrates deep into a substrate, binds down chalky surfaces and seals back stains.
The painter's job is to match the correct paint to the substrate. 40 years on it is still not obvious how to treat some jobs.