A question we get asked often is, “Can you paint latex over oil?"
The answer is, “yes”.
But you can’t treat it like latex or water-based surfaces.
If you put latex paint over oil, you’ll just end up with that fruit roll-up look all over your house because they just can’t adhere. Since they’re not compatible, they won’t form a good bond.
15-30 days after painting, you’ll even be able to peel that paint right off after getting the surface wet.
Yikes!
Why We Don’t Use Oil Based Paint
A lot of the older homes we paint in East Grand Rapids have oil-based paint on the plaster walls, trim, and cabinets. Oil-based paint was popular back in the ’70s and ’80s, especially on trim, cabinets, and doors. The most popular paint was a product called Satin Impervo.
There are a couple of reasons we don’t use oil-based paint anymore:
It emits a host of harmful VOCs (volatile organic content) that’s harmful to the environment.
Cleanup is messy since you have to use paint thinner
Latex paints are more flexible than oil-based paints and modern formulas are just as durable.
How To Tell If It’s Oil Or Not
To see if a surface has oil-based paint, we like to use a test affectionately named, “The Oil Paint Test” (We’re painters, not professional namers)
To do this test, simply use denatured alcohol from a brand like Klean Strip and rub it on the surface with a rag or cotton ball.
If the paint does NOT come off, the surface is oil-based paint.
If it doesn’t, then it’s water or latex-based paint.
How To Paint Over Oil Base Paint
Ok, so you’ve done the test and it comes back positive for oil-based paint, what do you do now?
Here’s what to do step-by-step:
First, lightly sand the surface and clean it with a sponge dipped in TSP (trisodium phosphate) mixed with water.
Allow the surface to dry
Coat it with an oil or latex bonding primer. If the original paint was really shiny, you’ll want to use a primer like Kilz. If it’s not too shiny, you can use a latex primer, then put a couple of latex coats over it.
Allow the primer to dry
Coat with two coats of high-quality latex paint.