[csjohnson]

It looks like the walls in my house have not been painted again since the house was built in the early 90s. Not sure if the interior paint is oil based or water based? It looks like a satin finish. I've primed before in other rooms before painting, but I am wondering going forward if I should prime anymore because it's an extra step that requires work and Sherwin Williams Duration says its a paint and primer in one.

If I use Duration Matte over Satin of unknown paint brand should I prime it first? What primer is best to use? Thanks!

 

[Biscuits]

I would prime paint that is over 20 years old.

 

[csjohnson]

I've always used Zinsser FastPrime 2 Interior Water-Base Primer & Sealer. Problem with that stuff is that is stinks terribly while applying it, which I can handle. But after it's dry it still tends to smell bad for months. Is there a better primer for going over old paint (interior). Not sure if the old interior paint is oil based or not, but it was painted in the early 90s.

 

[mark sr]

I haven't applied any flat oil interior paint since the 70s and I've never known of any issues apply latex wall paint directly over flat oil. Your woodwork could go either way. To test it for oil/latex take denatured alcohol, 'oops' or goof off' and scrub a small section. If it's latex it will dissolve the paint, with oil base it will only clean it.


If the walls were painted with a typical builder's flat paint I'd consider priming with Zinnser's Gardz.

 

[woodco]

You dont need to prime for repaints. 'Paint and primer in one' only refers to drywall, not the many other reason one should prime, like adhesion, or stain blocking. Just scuff sand the sills really good.

 

[jeffnc]

Clean if necessary to remove dust or airborne grease particles (for example from cooking). Lightly scuff sand the entire wall and you're good to go.