Yes, you can apply latex or oil paint over an oil based primer.

But can you put an oil based primer over a latex paint?

yes, you can put an oil based primer over latex paint.

You just can't put a latex paint over oil based paint unless you prime first - and most recommend sanding the oil down to a dull surface for better adhesion/durability.

"and most recommend sanding the oil down to a dull surface for better adhesion/durability."

Does this apply to putting an oil based primer over oil paint or a latex primer over oil paint? I was told by the paint store, if I used an oil primer I would not have to sand.

I think it would be helpful to state what the 'surface' is and whether it's inside or outside. As an example, I would not use an oil primer on an inside plaster/ sheet-rock wall and then paint latex/water over it.

It's discouraging that a paint store would give out advice that you don't need to sand. I don't think that an oil based primer is going to grip any better than a latex one either. If we were really going for adhesion, we would use BIN which is shellac based. Also, priming the oil based paint layer before painting with latex is not nearly as important as sanding it. I paint latex over oil all the time without a primer, but I do that because I know how to sand. Some homeowners may not know how to sand properly, so using a bonding primer is just an added safeguard. The best thing you can do is sand, then dust away the sanding dust and prime, then apply two topcoats. I would not mess around with the oil based priemr either. Just use a good bonding all acrylic primer like Fresh Start, Zinnser 123, C2 One, etc.

I ALWAYS tell my customers, in "usually" a direct way....

"I don't care what the label says...IDEALLY sand AND prime."

The final decision is now the customer's, and I've stated my recommendation....and the "WHY".

Faron

Thanks paintguy. What's funny is that the directions for the oil based primer called for sanding. Anyway I sanded the crown molding last night, took the oil back and bought some Zinnser 123 today. I will prime tomorrow.