There are two types of paints; water-based (latex) and oil-based. So, can you use latex paint over oil-based paint?
No, you cannot use latex paint over oil-based paint. This is because the oils in the oil-based paint won’t allow the latex to stick properly. So, if you apply latex over oil-based paint, the latex will stick but eventually peel off.
However, if you apply a primer over the old oil-based paint, you can apply latex paint.
- You cannot apply water-based paint (latex) over oil-based paint.
- You can apply oil-based paint over latex paint.
- You can use water-based paint over oil-based primer.
- You can use oil-based paint over the water-based primer.
- You cannot use water-based primer over oil-based paint.
- You can use oil-based primer over water-based paint.
Paint Over Primer
You can apply latex paint over oil-based primer. That’s because the oil-based primer has a different formula from oil-based paint. This makes latex paint and oil-based primer compatible.
However, you must prep the oil-based primer before applying the latex paint. To prep, sand the oil-based primer with fine-grit sandpaper before applying latex paint. Sanding will create tiny ridges and smoothen the primer surface. This allows the latex paint and oil-based primer to blend. If you don’t prep (sand) the primer before applying latex paint, the finish will peel off and crack.
You can also apply an oil-based paint over latex primer. However, the latex primer must dry fully before applying oil-based paint. Sanding latex primer before applying oil-based paint isn’t necessary, but it can help the paint to stick better.
Primer Over Paint
You cannot use water-based primer over oil-based paint. That’s because oil-based paint has a glossy finish that repels moisture, including paint or primer. So, if you apply water-based primer over oil-based paint, the primer will stick for a while, but the bonding won’t be good, and the primer will peel off.
It’s recommended to remove the oil-based paint and then apply the water-based paint. If you can’t remove the oil-based paint, use oil-based primer over oil-based paint.
However, you can use oil-based primer over water-based paint. The oil-based primer will stick to water-based paint and provide a smooth surface for the new paint.
Paint Over Paint
You can’t use water-based paint over oil-based paint. That’s because the dried paint particles of oil-based paint won’t allow the water-based paint to stick. Also, the glossy finish of oil-based paint will prevent latex paint from penetrating the paint coating. You must remove the oil-based paint before applying the latex paint.
However, you can apply oil-based paint over latex paint. That’s because latex paint doesn’t have a glossy finish that repels moisture or paint. Instead, water-based paint (latex) has a dry, textured finish that allows all paints to stick.
Why Oil and Latex Don’t Mix Well?
Oil and latex paint don’t mix because they have different paint solvents. Oil-based paint uses synthetic or natural oils as its paint solvent, while water-based paint uses water as its solvent. Oil and water-based paint dry through evaporation.
So, since they have different paint solvents, their drying time is different. Water-based paint dries faster than oil-based paint. That’s because the solvent (water) of water-based paint evaporates faster than oil-based paint’s solvent (oil).
If you mix latex paint and oil-based paint, the mixture will have two different paint solvents evaporating at different times. So, some parts of the finish will dry, while the other part won’t dry. This will lead to the mixture (paint) cracking and peeling off.