Before you paint over oil paint, or if you suspect it is oil-based and want to find out for sure, just do the following:
Dip a cotton ball into a small amount of denatured alcohol.
Rub it over a small area on the surface.
If the paint does NOT come off, it is oil-based paint and you will need to use a product that you can paint directly over oil-based paint or you can use an oil-based primer and then paint with latex paint. The primer can be latex, but it has to be a product that is made to prepare the surface and help with adhesion and that says “bonding” on the label. When the primer coats are dry, you can then successfully use latex paint.
If the paint comes off, it is a water or latex-based paint and you can proceed by painting over the surface with any type of paint.
